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Terry's Astronomy Thread.
Due to the recent spike in interest of the subject, I have decided to keep a regularly updated post-blog about what's happening in the night sky at a given day. I currently take an astronomy course and have a deep interest in the field, and the goal is to
a) Inspire people to enjoy the night sky differently than how it'd commonly be dismissed, thanks to light pollution. b) Spark interest in the subject. c) Educate people about the subject, and events in general. Everyone is welcome to post in this thread, after all the goal is to spark interest! How I will update the thread is this: For the daily-weekly sky at a glance, I will create a new post so that the topic remains active. For the picture of the day, or most other updates, I will update this post so that the main post is also updated. New posts I make will have a copy of all new information I post.j Things I will generally post about: Anything you can physically see in space, auroras, equipment (telescopes, binoculars, cameras, filters), deep space objects, light pollution. Recommend me any suggestions on how I can make this thread better! To make in the future: i) Glossary of terms ii) Better layout, structure, and a "topic-of-the-day". Statistics Charts:   Milestones: March 10, 2012: Astronomy Thread Created. March 17, 2012: Ascend to Page 2. March 21, 2012: Thread Eclipses 500 Views. April 1, 2012: Thread Stickied. April 4, 2012: Thread Eclipses 1,000 Views. April 10, 2012: 1 Month of Existence. (1,200 views, 38.7 visitors a day). May 10, 2012: 2 Months of Existence. (1,878 views, 30.8 visitors a day). May 15, 2012: Thread Eclipses 2,000 Views. June 26, 2012: Thread Eclipses 3,000 Views. (3003 views, 27.8 visitors a day). August 9, 2012: Thread Eclipses 4,000 Views. (4000 views, 26.49 visitors a day). August 10, 2012: 5 Months of Existence. (4055 views, 26.5 visitors a day). September 10, 2012: 6 Months of Existence. (5063 views, 27.6 visitors a day) . September 25, 2012: Thread Eclipses 6,000 Views (6015 views, 30.4 visitors a day). October 10, 2012: Thread Eclipses 7,000 views (32.87 visitors / day) and reaches the 7 month milestone. October 20, 2012: Thread Eclipses 8,000 views (35.75 visitors / day). 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March 10, 2014: Thread Reaches 2 Year Anniversary (47,532 viewers, 63.81 visitors / day)! March 13, 2014: Thread Eclipses 48,000 views (64.17 visitors / day). March 22, 2014: Thread Eclipses 49,000 views (64.73 visitors / day). March 31, 2014: Thread Eclipses 50,000 views (65.28 visitors / day). April 8, 2014: Thread Eclipses 51,000 views (65.89 visitors / day). April 14, 2014: Thread Eclipses 52,000 views (66.66 visitors / day). April 23, 2014: Thread Eclipses 53,000 views (67.16 visitors / day). July 22, 2014: Thread Eclipses 65,000 views (73.85 visitors / day). Updates: March 11, 2012: Added links found by Staiain and Mau5. Thanks guys! March 12, 2012: Center aligned "What's in the Sky Tonight?", "Aurora Tracker", and "Astro Pic of the Day". March 13, 2012: Implemented International Space Station Tracker. March 20, 2012: Organized, Improved links section. April 4, 2012: Added spoiler tags for the month of March to prevent slow computers from lagging. Implemented Light Pollution Map for Lower Canada, US, Northern Mexico, Europe, World. Also implemented a Messier Objects and general skymap. April 16, 2012: Added a video timelapse of ISS's view of the Earth, credit to Reach for finding the video! May 13, 2012: Added an Upcoming Events spoiler tag to see important fascinating events. October 26, 2012: Finished major maintenance of the main post, fixing bad spoiler tags buried in center tags, and did a cleanup of old entries to allow the main post to be updated again. the old entries have been archived; link is available at the end of the "Previous" sections of each entry. December 10, 2012: News feature added, meant to add interesting articles going on in space. March 10, 2013: New aurora monitors added for North and South Poles. July 18, 2013: New link added: NLC / Meteorite Calculator. July 20, 2013: Noctilucent Clouds Tracker feature added; track northern hemisphere NLCs to forecast when an ideal day would be to look out for them. September 16, 2013: Meteor Tracker added: discover how many meteroites are blazing through the North American skies and how fast they are travelling, and where they come from! Helpful Links Clear Dark Sky For North Americans only. You can use the light pollution maps and astronomer's forecasts found in this page to discover how optimal your viewing conditions are. Heavens Above Use this website to track the space station, other satellites, when you can see them pass over! The website also tracks comets, planets, and shows a picture of the orbits of the planets. Moon Phases Calendar Quick and convenient moon phases calendar, shows the month at a glance. (Thanks Mau5 for the find!) NLC / Meteorite Calculator Calculates the height of NLCs or meteorites given the coordinates of two observers' records. Sky and Telescope Great for an "at a glance", and the interesting article that I may pull out here time to time. Stellarium A tool you can download that simulates the night sky where you live. It is possible to go forward and backward in time to check how the sky may have looked in previous and future days. (Thanks Staiain for the find!) SWPC Real-Time Monitor Displays Real-time monitors of space weather. For auroras maps, go to "Estimate Planetary Kp". Telescopes and Binoculars Ever wanted to know information about good telescopes or a set of binoculars? Try looking here. Wiki List of Messier Objects This is a list of all 110 Messier objects. Good for quick reference. Suspicious0bservers Daily Weather Post: October 28, 2014 Past Posts: October 27, 2014 October 26, 2014 October 25, 2014 October 24, 2014 October 23, 2014 October 22, 2014 October 21, 2014 October 20, 2014 October 19, 2014 October 18, 2014 October 17, 2014 October 16, 2014 October 15, 2014 October 14, 2014 October 13, 2014 October 12, 2014 October 11, 2014 October 10, 2014 October 9, 2014 October 8, 2014 October 7, 2014 October 6, 2014 October 5, 2014 October 4, 2014 October 3, 2014 October 2, 2014 October 1, 2014 September 30, 2014 September 29, 2014 September 28, 2014 September 27, 2014 September 26, 2014 September 25, 2014 September 24, 2014 September 23, 2014 September 22, 2014 September 21, 2014 September 20, 2014 September 19, 2014 September 18, 2014 September 17, 2014 September 16, 2014 September 15, 2014 September 14, 2014 September 13, 2014 September 12, 2014 September 11, 2014 September 10, 2014 September 9, 2014 September 8, 2014 September 7, 2014 September 6, 2014 September 5, 2014 September 4, 2014 September 3, 2014 September 2, 2014 September 1, 2014 August 31, 2014 August 30, 2014 August 29, 2014 August 28, 2014 August 27, 2014 August 26, 2014 August 25, 2014 August 24, 2014 August 23, 2014 August 22, 2014 August 21, 2014 August 20, 2014 August 19, 2014 August 18, 2014 August 17, 2014 August 16, 2014 August 15, 2014 August 14, 2014 August 13, 2014 August 12, 2014 August 11, 2014 August 10, 2014 August 9, 2014 August 8, 2014 August 7, 2014 August 6, 2014 August 5, 2014 August 4, 2014 August 3, 2014 August 2, 2014 August 1, 2014 July 31, 2014 July 30, 2014 July 29, 2014 July 28, 2014 July 27, 2014 July 26, 2014 July 25, 2014 July 24, 2014 July 23, 2014 July 22, 2014 July 21, 2014 July 20, 2014 July 19, 2014 July 18, 2014 July 17, 2014 July 16, 2014 July 15, 2014 July 14, 2014 July 13, 2014 July 12, 2014 July 11, 2014 July 10, 2014 July 9, 2014 July 8, 2014 July 7, 2014 July 6, 2014 July 5, 2014 July 4, 2014 July 3, 2014 July 2, 2014 July 1, 2014 June 30, 2014 June 29, 2014 June 28, 2014 June 27, 2014 June 26, 2014 June 25, 2014 June 24, 2014 June 23, 2014 June 22, 2014 June 21, 2014 June 20, 2014 June 19, 2014 June 18, 2014 June 17, 2014 June 16, 2014 June 15, 2014 June 14, 2014 June 13, 2014 June 12, 2014 June 11, 2014 June 10, 2014 June 9, 2014 June 8, 2014 June 7, 2014 June 6, 2014 June 5, 2014 June 4, 2014 June 3, 2014 June 2, 2014 June 1, 2014 Older archived posts may be found here: January 1, 2014 - May 31, 2014 What's in the sky tonight? October 28, 2014 -Super-sunspot AR2192 produced another strong flare on Oct. 27th. The X2-category blast ionized the top of Earth's atmosphere and caused a strong HF radio blackout over the Atlantic Ocean basin as well in South America and western Africa. The blackout started at ~10:15 am EDT (1415 UTC) and lasted for about an hour. -High-latitude auroras are possible on Oct. 28th when Earth crosses through a fold in the heliospheric current sheet. This is called a "solar sector boundary crossing," and NOAA forecasters estimate a 40% chance of polar geomagnetic storms when it occurs. Previous Days: October 27, 2014 -AR2192 is the biggest sunspot in nearly 25 years, and it is still growing. The active region now covers 2750 millionths of the solar disk, an area equivalent to 33 planet Earths skinned and spread out flat. It is so large that sky watchers are seeing it with the naked eye when the sun is dimmed by low-hanging clouds or, in this case, dense fog. Barry Freas took the picture on October 26th from Red Hill, Kentucky. "It was a very foggy morning," he says. "AR2192 was remarkable." Big sunspots tend to produce strong flares, and AR2192 is no exception. It is crackling with magnetic activity. In the past three days alone it has unleashed 3 X-class flares and 8 M-flares. The most intense of these flares have caused HF radio blackouts and other communication disturbances on the dayside of Earth. Usually, strong flares are accompanied by massive CMEs--billion-ton clouds of electrified gas that billow away from the blast site. So far, however, none of the eruptions from AR2192 has produced a major CME. Without a series of CMEs to hit Earth and rattle our planet's magnetic field, there have been no geomagnetic storms nor any widespread auroras.  October 26, 2014 -Giant sunspot AR2192 is growing again, which means high solar activity is unlikely to subside this weekend. NOAA forecasters estimate an 85% chance of M-class flares and a 45% chance of X-flares during the next 24 hours. -Since Friday, AR2192 has produced two major X-class solar flares: X3 (Oct. 24 @ 2140 UT) and X1 (Oct 25 @ 1709 UT). An X2 erupted just 3 hours ago. -On Oct. 23rd, just as the New Moon was about to pass in front of the sun, the students of Earth to Sky Calculus launched a helium balloon carrying a Nikon D7000 camera. Their goal: to set the record for high-altitude photography of an eclipse. During a two-hour flight to the edge of space, the camera captured 11 images of the crescent sun. The final picture, taken just a split second before the balloon exploded, was GPS-tagged with an altitude of 108,900 feet. To put this achievement into context, consider the following: Most people who photographed the eclipse carefully mounted their cameras on a rock-solid tripod, or used the precision clock-drive of a telescope to track the sun. The students, however, managed the same trick from an un-stabilized platform, spinning, buffeted by wind, and racing upward to the heavens at 15 mph. Their photos show that DLSR astrophotography from an suborbital helium balloon is possible, and they will surely refine their techniques for even better photos in the future. Earth to Sky Calculus: https://www.facebook.com/pages/Earth...74490502634920   October 25, 2014 -Giant sunspot AR2192 erupted again on Oct. 24th (21:40 UT), producing a powerful X3-class solar flare. Using a backyard solar telescope, Sergio Castillo of Corona, California, was monitoring the sunspot when it exploded, and he snapped this picture. "This flare was so intense that it almost shorted out my computer! Well ... not really," says Castillo, "but I knew right away that it was an X-class eruption." A pulse of extreme UV radiation from the flare ionized the upper layers of Earth's atmosphere, causing a brief but strong blackout of HF radio communications over the dayside of Earth. Such blackouts may be noticed by amateur radio operators, aviators, and mariners. Coronagraph data from the Solar and Heliospheric Observatory (SOHO) suggest that the explosion did not hurl a significant CME toward our planet. (Interestinngly, none of the X-flares from this active region has so far produced a major CME.) As a result, Earth-effects may be limited to the radio blackout. -Sunspot AR2192, now facing Earth, is the largest sunspot of the current solar cycle. Sprawling across more than 200,000 km of solar terrain, wider than the planet Jupiter, this is the type of sunspot that comes along every 10 years or so. To put AR2192 in context, spaceweather.com reader Hagan Hensley of San Antonio TX placed it beside pictures of two other significant sunspots from the years 2001 and 1947. "Using Photoshop, I created this composite image of three big sunspots: AR2192 (2014), AR9393 (2001) and the great sunspot of 1947, the largest ever recorded," explains Hensley. "Positions on the solar disk shifted somewhat to avoid overlap." Spaceweather.com didn't exist in 1947, so we're not sure what happened then. In 2001, however, giant sunspot AR9393 was fully covered by the web site. In March of that year, the sunspot unleashed multiple X-flares, caused radio blackouts and radiation storms, and sparked red auroras seen as far south as Mexico. -Despite shrinking by ~10% on Oct. 24th, sunspot AR2192 remains the largest and most active sunspot of the current solar cycle. By far. NOAA forecasters estimate an 85% chance of M-class flares and a 45% chance of X-flares on Oct. 25th.   October 24, 2014 -The afternoon sun over North America looked a little unusual on Thursday. It was crescent shaped. James W. Young photographed the phenomenon from Wrightwood, California. "What a beautiful eclipse," says Young. "Sunspot AR2192 made it extra special." Millions of sky watchers in Canada, the USA and Mexico saw the Moon pass in front of the sun, covering as much as 70% of the solar disk over Alaska and as little as 12% over Florida. -I've also included my own shot of the same sunspot group from my 300mm lens in Toronto, albeit not a impressive of a shot.   October 23, 2014 -On Thursday, Oct. 23rd, the Moon will pass in front of the sun, off center, producing a partial solar eclipse visible from almost all of North America. This animated visibility map shows when to look. LINK: http://shadowandsubstance.com/ The event will be particularly beautiful in the Central and Eastern time zones where maximum eclipse occurs at sunset. The farther north and west you are, the deeper Thursday afternoon's partial solar eclipse will become.   October 22, 2014 -Solar activity is high. During the past 48 hours, monster sunspot AR2192 has produced a series of seven M-class solar flares of increasing intensity. The eruptions crossed the threshold into X-territory with an X1-class flare on Oct. 22nd. NASA's Solar Dynamics Observatory recorded a powerful flash of extreme UV radiation in the sunspot's magnetic canopy at 14:30 UT. Remarkably, not one of the explosions so far has hurled a significant CME toward Earth. The primary effect of the flares has been to ionize Earth's upper atmosphere, causing a series of short-lived HF radio communications blackouts. Such blackouts may be noticed by amateur radio operators, aviators, and mariners. Earth-effects could increase in the days ahead. AR2192 has an unstable 'beta-gamma-delta' magnetic field that harbors energy for powerful explosions, and the active region is turning toward Earth. NOAA forecasters estimate at 65% chance of M-class flares and a 20% chance of X-flares during the next 24 hours. Solar flare alerts: text, voice AR2192 is shaping up to be the biggest sunspot in many years. Its area is now approaching that of AR0486, the last great sunspot of the previous solar cycle, which covered 2610 millionths of the solar disc on Oct. 30, 2003. As of 0h UT today AR 2192 is 2410 millionths. (Thanks to Geoff Chester of the US Naval Observatory for this comparison.) The sun face from October 30, 2003 is shown below side-by-side with the sun face today for comparison. Because the sunspot is so large--now about as wide as the planet Jupiter--people are beginning to notice it at sunset when the sun is dimmed by clouds or haze. Pilot Brian Whittaker took this picture on Oct. 21st while flying 36,000 ft over Resolute, Nunavut, Canada. "I was impressed to photograph the giant sunspot as the sun set over Arctic Canada," says Whittaker. "Actually, the sun was temporarily rising because of our great relative speed over the lines of longitude at N75 degrees! Note the green upper rim."     October 21, 2014 -The biggest sunspot of the current solar cycle is turning toward Earth. This morning when astronomer Karzaman Ahmad of Malaysia's Langkawi Nagtional Observatory looked through the eyepiece of his solar telescope, he declared AR2192 a "monster" and snapped this picture. This behemoth active region is 125,000 km wide, almost as big as the planet Jupiter. These dimensions make it an easy target for backyard solar telescopes. A few days ago, AR2192 unleashed an X1-class solar flare. Since then the sunspot has almost doubled in size and developed an increasingly unstable 'beta-gamma-delta' magnetic field. It would seem to be just a matter of time before another strong explosion occurs. NOAA forecasters estimate at 60% chance of M-class flares and a 20% chance of X-flares on Oct. 21st. -A high-speed stream of solar wind is buffeting Earth's magnetic field, sparking bright lights around both poles. "This evening the auroras appeared everywhere," reports Anne Birgitte Fyhn, who photographed the display from a pond on Kvaløya island, Tromsø, Norway. "They were amazing," she says. "I ran around the pond a couple of times taking pictures from different spots. Finally, I decided to just sit down, look up, and enjoy the show." High-latitude sky watchers should remain alert for auroras on Oct. 21-22. NOAA forecasters estmate a 45% chance of geomagnetic storms as the solar wind continues to blow.   October 20, 2014 -Big sunspot AR2192 has grown even bigger, spreading across 1/3rd more solar terrain today than it did yesterday. NASA's Solar Dynamics Observatory recorded the expansion. The chances of an explosion are growing along with the sunspot. On Oct. 20th, NOAA forecasters boosted the odds of an M-class flare to 60% and an X-flare to 20%. Yesterday, the sunspot produced a long-duration X1-flare and a strong HF radio blackout over Asia and Australia. The next X-flare, if one occurs, will be even more geoeffective as the sunspot turns toward Earth. If you have a solar telescope, now is a great time to look at the sun. AR2192 looks absolutely spectacular.  October 19, 2014 -Today, Oct. 19th, Comet Siding Spring is buzzing Mars. The encounter is so close, the atmosphere of the comet could brush against the atmosphere of the planet. Will this spark auroras on Mars? Follow a webcast of the encounter courtesy of the Virtual Telescope project; watch in real time starting at 16:45 UT (12:45 p.m. EDT) today, or watch the recording later. LINK: http://www.virtualtelescope.eu/2014/...-online-event/ -This comes as no surprise. Behemoth sunspot AR2192 has unleashed an X1-class solar flare. NASA's Solar Dynamics Observatory recorded the blast in this extreme UV image of the sun on Oct. 19th (0500 UT). A pulse of ultraviolet and X-radiation from the flare caused a brief but strong HF radio blackout on the dayside of Earth, mainly over Asia and Australia. Also, the explosion probably hurled a CME into space. This possibility has not yet been confirmed by SOHO coronagraph data. If a CME is forthcoming, it will probably sail wide of Earth due to the sunspot's location near the sun's eastern limb. Big sunspots tend to produce big flares, and clearly AR2192 is no exception. More X-flares are likely as AR2192 turns toward Earth in the days ahead. Also, if you have a solar telescope, point it at the sun. This active region is a real beauty.     October 18, 2014 -Most rainbows are caused by light reflected once, or sometimes twice, inside raindrops. Larger numbers of reflections are possible, but the rainbows they create are very rare. After years of searching, atmospheric optics experts have sighted a rainbow caused by five reflections, the elusive 5th-order rainbow. Details here: http://www.atoptics.co.uk/fz1063.htm Publication: http://www.opticsinfobase.org/ao/abs...ri=ao-54-4-B26 -A large and active sunspot is rotating over the sun's southeastern limb on Oct. 17th. J. P. Brahic sends this picture of the behemoth to spaceweather.com from Uzès, France: "I inserted a picture of Earth for scale," says Brahic. The sunspot's primary dark core could swallow our entire planet with room to spare. This sunspot could cause a sharp increase in solar activity over the weekend. Earlier this week, while it was still hidden behind the southeastern limb, the active region unleashed several M-class solar flares and hurled a massive CME into space. Considering the fact that the blast site was partially eclipsed by the edge of the sun, those flares were probably much stronger than their nominal classification. Now that the sunspot has revealed itself, X-flares may be in the offing.  October 17, 2014 -Before dawn Saturday morning, Jupiter shines above the waning Moon, as shown at right. Although they look rather close together, Jupiter is 2,100 times farther in the background — it's at a distance of 47 light-minutes, compared to the Moon's 1.3 light-seconds. -On Sunday, Oct. 19th, Comet Siding Spring will pass only 140,000 km away from Mars. For comparison, that's about 1/3rd the distance between Earth and the Moon. For a while last year, astronomers thought the comet might actually hit Mars, setting off a cataclysmic climate change experiment, but now we know it's going to be a near miss. Last night, only three days before closest approach, astrophotographer Damian Peach snapped this picture. "The comet is presently moving against the dense star clouds of the southern Milky Way," says Peach. "Soon, however, it will reach Mars." An international fleet of Mars orbiters and rovers will observe the encounter from close range. The most interesting data could come from MAVEN, a NASA spacecraft that has reached Mars just ahead of the comet. MAVEN is designed to study the martian atmosphere. That's good, because when the comet arrives, the atmosphere of the comet will likely brush against the atmosphere of Mars, possibly sparking auroras on the Red Planet. MAVEN could record these alien lights. "Just as exciting," adds comet researcher Karl Battams of the Naval Research Lab, "is the prospect of the Mars Reconnaissance Orbiter's HiRISE camera being able to actually resolve (i.e. determine the shape of) the nucleus of the comet. ESA and NASA spacecraft have seen comet nuclei before, but comet Siding Spring is a little different. It's an 'Oort Cloud comet' on its first ever foray into our solar system. This means it is largely pristine and will likely not have undergone any major changes since it formed. We've never seen one of these comets up close. Never. We don't know exactly what to expect." Experienced amateur astronomers with mid-sized telescopes and sensitive digital cameras should have no trouble photographing Comet Siding Spring in the nights ahead. It can be found glowing like a 12th magnitude star in the constellation Ophiuchus right next to ... you guessed it ... the planet Mars.  October 16, 2014 -For the second day in a row, auroras are dancing around the Arctic Circle. The lights were sparked by a minor CME impact on Oct. 14th and amplified on Oct. 15th when Earth passed through a fold in the heliospheric current sheet. NOAA forecasters estimate a 40% chance of continued polar geomagnetic storms on Oct. 16th. -A sunspot capable of powerful eruptions is about to rotate onto the Earthside of the sun. It announced itself on Oct. 14th by hurling a spectacular CME over the sun's southeastern limb: The underlying explosion was hidden behind the southeastern edge of the sun. Even in eclipse, however, the blast registered M2 on the Richter Scale of Solar Flares. The actual rating must have been must higher, perhaps even X-class.  October 15, 2014 -This Sunday, Oct. 19th, Comet Siding Spring will pass only 140,000 km from Mars. The encounter is so close, the atmosphere of the comet could brush against the atmosphere of the planet. Will this spark auroras on Mars? A video below from NASA weighs the odds of some very strange space weather. -Last-quarter Moon (exactly so at 3:12 p.m. Eastern Daylight Time). The Moon rises around midnight tonight, below Gemini. By early dawn on Thursday the 16th it's very high in the south — with Pollux and Castor above it, Procyon to its lower right, and bright Jupiter shining farther to its lower left. October 14, 2014 -When the European Space Agency's Rosetta probe arrived at Comet 67P/Churyumov–Gerasimenko in August, one of the biggest surprises was the boulders: The comet's core is littered with them. Rosetta's OSIRIS camera photographed this specimen, a 45-meter-wide behemoth named "Cheops," on Sept. 19th. On Nov. 12th, Rosetta will drop a lander onto the surface of the comet, and these boulders are a key hazard Philae must avoid. But are they really boulders? "Maybe they only look like rocky boulders," says Art Chmielewski, the US Rosetta Project Manager at JPL. "Some scientists believe that they are 'flimsy' boulders. They may be more like dirty snow balls made in very cold weather. If so they are very fragile and would collapse under the lander. I hope Philae will not find out if that is true." Claudia Alexander, the Project Scientist for the US Rosetta Project says the boulders could be telling us something new about the way comets "sublimate"--that is, the way sunlight converts cometary ices into jets of gas. "I personally wonder if we've gotten the sublimation process understood in the reverse. In other other words, instead of sublimation coming forth from a crack or fissure in the ground, sublimation emerges from cliff-sides, or 'spires' or vertical features, and then these features collapse when the vapor has been evacuated." Boulders could be debris from such a process. "Obviously Rosetta is perfectly poised to make the measurements that will help us understand the physics of this process, and better understand cometary geology!"  October 13, 2014 -High-latitude auroras are possible on Oct. 14th when Earth crosses through a fold in the heliospheric current sheet. This is called a "solar sector boundary crossing," and NOAA forecasters estimate a 25% chance of polar geomagnetic storms when it occurs. -Look up at the Moon. The surface of Earth's satellite never seems to change. Indeed, planetary scientists have long thought that lunar volcanism came to an abrupt end about a billion years ago, and little has changed since. On Oct. 12th, NASA announced evidence to the contrary. A camera onboard the Lunar Reconnaissance Orbiter (LRO) has found signs of eruptions that occurred no more than 100 million years ago. 100 million years may sound like a long time, but in geological terms it's just a blink of an eye. The volcanic craters LRO found were erupting during the Cretaceous period--the heyday of dinosaurs. Some of the volcanic features may be even younger, 50 million years old, a time when mammals were replacing dinosaurs as dominant lifeforms. "This finding is the kind of science that is literally going to make geologists rewrite the textbooks about the Moon," said John Keller, LRO project scientist at the Goddard Space Flight Center." Using its high-resolution camera, LRO has found scores of these geologically "fresh" eruptions. The features are too small to be seen from Earth, averaging less than a third of a mile (500 meters) across in their largest dimension, but they appear to be widespread. "These young volcanic features are prime targets for future exploration, both robotic and human," said Mark Robinson, principal investigator for the Lunar Reconnaissance Orbiter Camera (LROC) at Arizona State University.  October 12, 2014 -There are only two sunspots visible on the solar disk, and both of them appear to be in a state of decay. NOAA forecasters estimate a waning 20% chance of M-flares and only a 1% chance of X-flares this weekend. -Orion preview: With fall well underway, the "winter" constellation Orion rises in the east by 11 or midnight, depending on how far east or west (respectively) you live in your time zone. It's well to the lower right of the waning Moon. Orion's Belt will be vertical, as it always is when Orion is rising for mid-northern skywatchers. Orion reaches its highest stand in the south well before the first light of dawn, with the Moon now above it (on the morning of the 13th).  October 11, 2014 -The Moon late this evening shines near Aldebaran amid the Hyades. Take a look with binoculars. This will be a challenging scene to photograph (use a long lens), what with the Moon's brilliance and the Hyades stars' faintness. By dawn they've moved over to high in the southwest. -A magnetic filament near the sun's southwestern limb collapsed during the late hours of Oct. 10th. Earth-orbiting satellites detected a C3-class Hyder flare when the filament hit the solar surface: movie. The eruption also hurled a CME into space, but the storm cloud appears set to miss Earth. October 10, 2014 -NOAA forecasters have raised the odds of an M-class solar flare today to 40%. The likely source is sunspot AR2182, which has tripled in size since yesterday. Because the sunspot is near the sun's western limb, however, its flares may not be geoeffective. -At this time of year, only a few weeks after the equinox, Northern Lights are almost always visible somewhere around the Arctic Circle. "Last night I was flying to Europe from Calgary and I strategically selected the window seat hoping for a show," reports traveler Christy Turner. This is what she saw. "Boy did I luck out!" she says. Indeed she did. During her flight, the interplanetary magnetic field (IMF) around Earth tipped south. South-pointing IMFs pry open a crack in Earth's magnetosphere, allowing solar wind to pour through and ignite auroras.  October 9, 2014 -During a lunar eclipse, the normally-bright full Moon darkens as it passes through the shadow of Earth. Millions of sky watchers witnessed this beautiful dimming on Oct. 8th. David Boatwright of Californiia experienced the eclipse in a different way. His solar array browned out. "My home has a 4.5 kW photovoltaic solar system on its roof," he explains. "During the day it produces a good amount of electricity. It even produces a couple of volts from ambient light at night. A full Moon will increase it to nearly 4 volts DC when overhead." "Pictured above is a screen shot of the power output from my system. As you can see, it recorded the lunar eclipse. The voltage was cut in half during totality. From 3:30am to 4:30am PDT, the DC voltage dropped from 4 volts to 2 volts and then back up to 3volts at the conclusion of the eclipse. I believe the 1 volt difference, before vs. after the eclipse, is due to the Moon being lower in the sky when the eclipse ended." "By the way, I was watching the eclipse in my backyard as this voltage drop was occurring," he says.  October 8, 2014 -Solar activity is low, and the quiet is likely to continue. Not one of the six sunspot groups on the disk of the sun has the type of unstable magnetic field that poses a threat for strong eruptions. NOAA forecasters estimate a scant 5% chance of M-flares on Oct. 8th. -Altair is the brightest star high in the south at nightfall. Very far to its lower left (about six fist-widths) is Fomalhaut, almost as bright. -As the total lunar eclipse ends and the moon sets over the North American continent, like almost all other lunar eclipses, there is a solar eclipse that joins it in 2 weeks. The October 23 partial solar eclipse also favours North America, and the further north in latitude you are, the better your chance of seeing it. The further west you are, the more likely you are to see the whole thing. Use this link to find out how much of an eclipse you will have! http://eclipse.gsfc.nasa.gov/SEsearc...p?Ecl=20141023 For those around the Toronto latitude, you are looking at a 50% cover at maximum eclipse. Toronto will see the eclipse as the sun sets.  October 7, 2014 -On Wednesday morning, Oct. 8th, there will be a total lunar eclipse. Observers across the Pacific side of Earth can see the normally-pale full Moon turn a beautiful shade of red as it passes through the sunset-colored shadow of our planet. The Moon first dips into Earth's shadow at approximately 9:15 UT (2:15 a.m. PDT), kicking off the partial phase of the eclipse. Totality, when the Moon is fully immersed, begins at 10:25 UT (3:25 a.m. PDT) and lasts for nearly an hour. Details: http://eclipse.gsfc.nasa.gov/OH/OHfi...2014-Fig03.pdf  October 6, 2014 -As twilight fades, look for Arcturus, the Spring Star, twinkling in the west to west-northwest. It's still pretty easy to see. But how much later into the fall, as it sinks away, will you be able to keep it in view? -Jupiter (magnitude –1.9, at the Cancer-Leo border) rises in the east-northeast around 2 or 3 a.m. It shines brightly high in the east before and during dawn. It forms a big triangle with Pollux above it (by about two fists at arm's length) and Procyon to their right. Look below Jupiter and a bit left for Regulus. October 5, 2014 -The sun is peppered with spots, but not one of the eight numbered sunspot groups on the solar disk has the type of unstable magnetic field that poses a threat for strong flares. Solar activity is low. NOAA forecasters estimate a 15% chance of M-flares today, decreasing to only 5% tomorrow. October 4, 2014 -The W pattern of Cassiopeia stands vertically (on its dimmer end) high in the northeast around 10 or 11 p.m., depending on your location. By then the Big Dipper is lying level just above the north-northwest horizon — if you live in the mid-northern latitudes. As far south as San Diego and Jacksonville, the Dipper will lie partly below the horizon. -Mark your calendar. On Wednesday morning, Oct. 8th, observers across the Pacific side of Earth will see the Moon turn a beautiful shade of red as it passes through the sunset-colored shadow of our planet. Totality begins at 10:25 UT (3:25 a.m. PDT) and lasts for nearly an hour. Don't miss it! Details: http://eclipse.gsfc.nasa.gov/LEplot/...2014Oct08T.pdf -The Moon is waxing full. That means now is a good time to look for lunar coronas. Lauri Kangas photographed this specimen over Fort Frances, Ontario, on October 2nd. Lunar coronas are made of moonlight diffracted by tiny droplets of water in the air. Sometimes the droplets are supplied by passing clouds. This time, however, they came in the form of fog. "Late in that evening the temperature dropped rapidly and a ground fog developed," says Kangas. "I could see the tiny water droplets with my flashlight. These water droplets formed a beautiful corona around the Moon. To the naked eye the blue colored ring was awesome." Rings around the Moon also form when ice crystals drift by, but those are ice halos, and they have a different appearance.  October 3, 2014 -Departing sunspot complex AR2172-AR2173 erupted on Oct. 2nd around 1915 UT, producing an M7-class solar flare. NASA Solar Dynamics Observatory photographed a massive plume of debris flying away from the blast site. A flash of UV radiation from the flare ionized the top of Earth's atmosphere, briefly disturbing the normal propagation of shortwave and VLF radio signals on the dayside of Earth. Otherwise there should be few Earth-effects from this eruption. Perched on the sun's western limb, the instigating sunspot group is not facing our planet and most of the explosion's debris should sail wide of Earth. There is a slim chance that a CME emerging from the blast site could deliver a glancing blow to Earth's magnetic field in a few days. To evaluate this possibility, NOAA analysts are looking carefully at coronagraph data from SOHO and STEREO.  October 2, 2014 -If you thought an X1-class solar flare was bad, how about an X100,000? NASA's Swift spacecraft has detected such a explosion. Fortunately for life on Earth, it did not come from the sun. The source of the super-flare was another star almost 60 light-years away. -It only looks like a lunchbox. Pictured below is a Space Weather Buoy--an insulated capsule containing a cosmic ray detector, video cameras, GPS trackers, and other sensors. On Sept. 28th, it flew 115,000 feet above Earth's surface to check radiation levels in the stratosphere. This picture was taken at the apex of the flight. In collaboration with Spaceweather.com, the students of Earth to Sky Calculus have been launching these buoys on a regular basis to study the effect of solar activity on Earth's upper atmosphere. Their latest flight has a sharply defined purpose: to find out if stratospheric radiation is rebounding from a "Forbush Decrease" earlier this month. The story begins on Sept. 12th when a CME hit Earth head-on, sparking the strongest geomagnetic storm of the year. The students launched a Space Weather Buoy into the storm, expecting to measure an increase in energetic particles. Instead of more, however, they measured less. The CME swept away many of the cosmic rays around Earth and, as a result, radiation levels in the stratosphere dropped. This counterintuitive effect is called a "Forbush Decrease" after the 20th century physicist Scott Forbush who first described it. Now that the CME is long gone, cosmic radiation levels around Earth should be returning to normal. But are they? The answer lies inside the payload, which a team recovered yesterday from a remote landing site in Death Valley National Park. Stay tuned. Note: The students wish to thank Sander Geophysics for sponsoring this flight. (Note their logo in the upper right corner of the payload.) Their generous contribution of $500 paid for the helium and other supplies necessary to get this research off the ground.  October 1, 2014 -So far this week, solar activity has been low. However, there are five sunspots on the solar disk poised to break the quiet. All of them have 'beta-gamma' magnetic fields that harbor energy for moderately strong eruptions. NOAA forecasters estimate a 65% chance of M-class solar flares and a 15% chance of X-flares. -For the 5th day in a row, observers around the Arctic Circle are reporting dynamic auroras. Pilot Brian Whittaker photographed this outburst on Sept. 30th while he was flying 35,000 feet over Hudson Bay, Canada. "For many hours we watched the sky come alive, often with rapid pulses," Whittaker says. "It was mostly cloudy below, but a fantastic show at 35,000 ft." The ongoing display is a result of our planet's response to the interplanetary magnetic field (IMF). For days the IMF has been tipping south, slightly, just enough to open a crack in Earth's magnetosphere. Solar wind leaks in to fuel the auroras. Conditions favor more auroras tonight. NOAA forecasters estimate a 35% chance of polar geomagnetic storms on Oct. 1st. However, a full-fledged storm is not required for Northern Lights at this time of year. The odds of Arctic auroras are, therefore, quite a bit higher than 35%.  September 30, 2014 -Arcturus is the bright star due west at nightfall. It's an orange giant 37 light-years away. Off to its right in the northwest is the Big Dipper, most of whose stars are about 80 light-years away. They're both sinking lower every week now. -Saturn (magnitude +0.6, in Libra) is sinking away into the afterglow of sunset. Look for it well to the right of the Mars-Antares pair, and probably a little lower depending on your latitude. September 29, 2014 -There are now four sunspot groups on the solar disk with unstable magnetic fields, which means an eruption today is likely. NOAA forecasters have raised the daily odds of an M-class solar flare to 75% and an X-flare to 15%. -While much attention is being paid to the fact that September's equinox kicked off aurora season in the Northern Hemisphere, we should not forget that the Southern Hemisphere has just experienced the exact same equinox. It is aurora season there, too. Petr Horálek sends this example of Southern Lights over Lauder, New Zealand, on Sept 25th. "The auroras burned very low above the southern horizon here at the NIWA atmospheric research station," Horálek says. "The opened dome is the BOOTES telescope, which is used to detect the optical afterglow of distant gamma-ray bursts. A green lidar behind me reflected from the dome, giving it a green hue." For reasons researchers do not fully understand, at this time of year even gentle gusts of solar wind can ignite beautiful auroras. Right now Earth is passing through a minor stream of solar wind that has both poles aglow.  September 28, 2014 -Weekend fireworks were predicted, and the sun complied. On Sunday, Sept. 28th (0258 UT), the magnetic canopy of sunspot AR2173 erupted, producing an M5-class solar flare. The sun was high overhead in Australia when Matt Wastell of Brisbane photographed the explosion. Extreme UV radiation from the flare ionized the top of Earth's atmosphere, disturbing the normal propagation of radio transmissions around our planet. In particular, there was a limited blackout of HF radio communications and a probable loss of shortwave radio contact in daylit areas for some tens of minutes. At the moment, we do not know if this explosion hurled a coronal mass ejection (CME) toward Earth. Based on the impulsiveness (brevity) of the flare, we think not. A final answer awaits coronagraph data from the SOHO and STEREO spacecraft. Wastell's picture, which he took using a solar telescope tuned to the red glow of solar hydrogen, shows more than a half-dozen dark magnetic filaments winding across the face of the sun. Like sunspots, these filaments pose a threat for flares. When a magnetic filament collapses it can hit the stellar surface and explode, causing a type of "spotless" explosion called a Hyder flare. Taking into account all of the sunspots as well as the filaments, NOAA forecasters estimate a 65% chance of M-class flares and a 10% chance of X-flares in the next 24 hours.  September 27, 2014 -Fast-growing sunspot AR2175 has developed a 'beta-gamma-delta' magnetic field that harbors energy for significant eruptions. As a result, NOAA forecasters have upped the daily odds of M-class flares to 65% and X-flares to 10%. Stay tuned for weekend fireworks. -During the early hours of Sept. 26th, something exploded behind the southeastern edge of the solar disk. NASA's Solar Dynamics Observatory photographed a massive plume of debris rising over the sun's limb. As the inset shows, the plasma-plume was big enough to swallow dozens of planets Earth. In this case, however, Earth was not in the line of fire. The ejecta will completely miss our planet. X-rays from the eruption registered C8 on the Richter Scale of Solar Flares. The actual intensity must have been much higher, though, because the flare was eclipsed by the edge of the sun. The underlying active region might be potent. In a few days, the blast site will emerge into view as the sun's rotation turns it toward Earth. Then we will be able to evaluate its potential for future eruptions, increasingly geoeffective as the sun slowly spins on its axis.  September 26, 2014 -New sunspot AR2175 didn't exist one day ago. Now it stretches more than 100,000 km across the face of the sun with a primary dark core larger than Earth. The fast-growing region has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. -As early as 8 or 9 p.m. now look for Fomalhaut, the lonely 1st-magnitude Autumn Star, twinkling on its way up from the southeast horizon. It will be highest due south around 11 or midnight (depending on your location). -The waxing crescent Moon works its way eastward above the star-and-planet display low in the southwestern twilight. (These scenes are plotted for the middle of North America.)  September 25, 2014 -A CME launched into space by the M2-class flare of Sept 23rd will not hit Earth, according to NOAA analysts. Forecast models predict that it will sail wide of our planet. More CMEs may be in the offing, however. The source of the Sept. 23rd explosion, big sunspot AR2172, has an unstable magnetic field that is likely to erupt again. Because the sun's rotation is turning the sunspot toward Earth, future CMEs will probably be geoeffective. -How do you know it's autumn in Iceland? It's when the icebergs turn green. Last night, Steve Lansdell photographed the phenomenon from the Jokulsaron Ice Lagoon. "We've seen auroras 4 nights in a row, but last night was really spectacular," says Lansdell. "The green lit up the icebergs in a wonderful display that thrilled my friends." These are equinox auroras, appearing less than 48 hours after the onset of northern autumn. For reasons researchers don't fully understand, auroras love equinoxes. At this time of year even a gentle gust of solar wind can spark a beautiful display. Mindful of the season, NOAA forecasters estimate a 50% chance of more polar geomagnetic storms--and more green ice--in the next 24 hours.  September 24, 2014 -Today, the interplanetary magnetic field (IMF) near Earth is tilting south, not much, but enough to open a crack in Earth's magnetosphere. Solar wind is pouring through the opening to fuel beautiful polar auroras. NOAA forecasters estimate a 40% chance that a full-fledged geomagnetic storm could develop in the next 24 hours. -Northern autumn began with a bang, albeit only a medium-sized one. Big sunspot AR2172 erupted on Sept. 23rd at 2316 UT, producing an impulsive M2-class solar flare. NASA's Solar Dynamics Observatory captured the extreme ultraviolet flash. The explosion might have hurled a CME toward Earth, but SOHO and STEREO coronagraph data are not yet available to confirm this possibility. Stay tuned for updates in the hours ahead. Meanwhile, more flares are in the offing. AR2172 continues to grow and it has a 'beta-gamma' magnetic field that harbors energy for strong explosions. NOAA forcasters estimate a 30% chance of M-class flares and a 5% chance of X-flares on Sept. 24th.  September 23, 2014 -Solar activity is low. However, new sunspot AR2172 threatens to break the quiet. Karzaman Ahmad photographed the behemoth active region on Sept. 22nd from the Langkawi National Observatory in Maylasia. The sunspot's primary dark cores are nearly as wide as Earth, and the entire group stretches more than 80,000 km from end to end. These dimensions make AR2172 an easy target for small solar telescopes. "I took the picture using an 11-inch telescope," says Ahmad. Yesterday, for a while, the sunspot's magnetic field displayed an unstable mixture of polarities that harbored energy for strong explosions. Now the threat has subsided. As the situation shifts back and forth, NOAA forcasters estimate a 30% chance of M-class flares and a 5% chance of X-flares on Sept. 23rd. -Today, Sept. 23rd at 0229 UT, the sun crossed the celestial equator heading south. The crossing marks the beginning of fall in the northern hemisphere--a.k.a. the autumnal equinox. Equinox means equal night. With the sun near the celestial equator, we experience equal amounts of daylight and darkness, 12 hours of each. Good news for sky watchers: It's also the beginning of aurora season.  September 22, 2014 -NOAA forecasters estimate a 30% chance of polar geomagnetic storms on Sept. 23-24 when a co-rotating interaction region (CIR) is expected to hit Earth's magnetic field. CIRs are transition zones between fast- and slow-moving solar wind streams. Solar wind plasma piles up in these regions, producing density gradients and shock waves that do a good job of sparking auroras. -The northern autumnal equinox is less than a day away. That's good news for sky watchers because, for reasons researchers do not fully understand, auroras love equinoxes. At this time of year even gentle gusts of solar wind can spark a nice display of Northern Lights. Igor Matveev took the picture on Sept. 19th from Monchegorsk, Russia. There was no geomagnetic storm predicted that night--and no meteor shower. Yet Matveev saw both. "What luck!" he says. "I caught the entire meteor streaking beneath the auroras." No CME was required to spark the auroras. Instead, a relatively minor fluctuation in the magnetism of the solar wind caused the display. Tomorrow's CIR (co-rotating interaction region), explained above, could be even more effective.  September 21, 2014 -On Sept. 23th the sun will cross the celestial equator heading south, marking the end of northern summer. That's good news for high-latitude sky watchers because, for reasons researchers do not fully understand, auroras love equinoxes. At this time of year when the seasons are changing, even gentle gusts of solar wind can spark a nice display of Northern Lights. Harald Albrigtsen took the picture on Sept. 19th from Kvaløya, Norway. There was no geomagnetic storm predicted that night, and indeed no CME struck our planet. Instead a relatively minor fluctuation in the magnetic orientation of the solar wind sparked the display. NOAA forecasters estimate a 30% chance of polar geomagnetic storms on Sept 21st, and the probability of Arctic auroras is probably even higher than that. -Sky watchers in parts of California are finding that, suddenly, they can view sunspots without a solar telescope. Smoke from the epic King Fire is providing a natural filter. David Wheat photographed the fiery sunset from Tuolumne CA. "Notice the 3 sunspots on the upper left of the solar disk " points out Wheat. The fire, which began a week ago in a canyon east of Sacramento, has ballooned in size to 80,000 acres, larger than the city of Portland. Dense smoke has grounded planes and choked the air for hundreds of miles around the blaze--including a Sierra peak where the headquarters of Spaceweather.com is located. Because the fire is only 10% contained, fiery sunsets will likely continue for days to come.    September 20, 2014 -Although the sun is peppered with spots, not one them has the type of complex magnetic field that harbors energy for strong explosions. NOAA forecasters estimate a slight 20% chance of M-class solar flares during what should be a quiet weekend. -In bright twilight, Mercury and fainter Spica are in conjunction 0.6° apart just above the west-southwest horizon. Use binoculars to scan for them about 20 minutes after sunset. The eclipsing variable star Algol (Beta Persei) should be at its minimum light, magnitude 3.4 instead of its usual 2.1, for a couple of hours centered on 10:55 p.m. EDT. In early dawn on Sunday the 21st, the waning crescent Moon shines far below Jupiter and closer to the right of Regulus, as shown below. September 19, 2014 -No geomagnetic storm was in the forecast for Sept. 19th, but a storm occurred anyway. Sky watchers around the Arctic Circle saw the midnight sky turn green as magnetometers registered an unexpected G1-class disturbance between 0300 and 0600 UT. "Suddenly there were lots of Northern Lights above the Lofoten Islands of Norway," reports Eric Fokke, who put his camera on the ground to record the display through a patch of mushrooms. "Unfortunately there was no Moon to illuminate the mushroms, so I had to take this picture under streetlights," says Fokke. "The auroras were bright enough to see despite the manmade glare." The source of the display was a fluctuation in the interplanetary magnetic field (IMF). During the early hours of Sept. 19th, the IMF tipped south, opening a crack in our planet's magnetosphere. Solar wind poured in to fuel the storm. NOAA forecasters estimate a 20% chance of more polar geomagnetic storms tonight. In other words, if you're an Arctic photographer, there's a 1 in 5 chance you should find a pumpkin patch.  September 18, 2014 -A minor CME expected to hit Earth's magnetic field on Sept. 17th apparently did not. Either it sailed wide of our planet or its impact was too puny to detect. With no CME to rattle Earth's magnetic field, NOAA forecasters have downgraded the chances of a geomagnetic storm today to only 20%. -Iceland's largest volcano is restless. The Bardarbunga volcano system, located under the massive Vatnajoekull glacier, has been rocked by hundreds of tremors daily since mid-August. Lava is currently spewing from fissures, prompting fears of a much larger eruption. Local photographers, meanwhile, are having a great time recording a rare mix of lava-red and aurora-green in the night sky. Thorsten Boeckel sends this photo from Mývatn, Iceland. "The red shine of the fissure eruption together with the green aurora provided a phantastic view," he says. A full-fledged eruption of this volcano has the potential to be even more disruptive than the 2010 eruption of nearby Eyjafjallajokull, which threw air traffic into chaos across Europe. According to the Icelandic Met Office, there are no signs of decreasing magma output as of Sept. 17th. This means more lava is in the offing--along with more phantastic photo-ops as aurora season unfolds around the Arctic Circle.  September 17, 2014 -A slow-moving CME propelled toward Earth by an erupting magnetic filament on the sun is expected to arrive today, Sept. 17th. NOAA forecasters estimate a 50% chance of minor geomagnetic storms in response to the sluggish impact. High-latitude sky watchers, be alert for auroras. -On Sept. 12th, a CME hit Earth's magnetic field, igniting the most intense geomagnetic storm of the year. The students of Earth to Sky Calculus quickly launched a helium balloon to the stratosphere to see what effect the storm was having on Earth's upper atmosphere. They expected to measure more radiation than usual. Instead, they measured less. This plot shows a sharp drop in high energy radiation on Sept. 12th compared to previous flights in May, June, and August. What caused this counterintuitive drop? Answer: When the CME swept past Earth, it swept aside many of the cosmic rays that normally surround our planet. The effect is called a "Forbush Decrease," after American physicist Scott F. Forbush who first described it. Wherever CMEs go, cosmic rays are deflected by magnetic fields inside the CME. Forbush decreases have been observed on Earth and in Earth orbit onboard Mir and the ISS. The Pioneer 10 and 11 and Voyager 1 and 2 spacecraft have experienced them, too, beyond the orbit of Neptune. Now high school students have detected a Forbush Decrease in the stratosphere using little more than an insulated lunchbox and a helium balloon. The balloon's lunchbox-payload is shown here suspended almost 110,000 feet above the Sierras of central California. Inside the payload, there was a high-energy radiation sensor, a cryogenic thermometer, multiple GPS altimeters and trackers, and three cameras. During the 2.5 hour flight, the buoy collected more than 50 gigabytes of video and science data ranging in altitude from 8500 ft to 113,700 ft above sea level. The analysis is still underway. The students wish to thank Caisson Biotech LLC for sponsoring this flight. Note their logo on the upper right corner of the payload! -If you would like to sponsor an upcoming balloon launch, support the next generation of scientists, and have your logo flown to the edge of space, please contact Dr. Tony Phillips to make arrangements. The cost of sponsorship is $500. Sponsors receive a complete video of the flight along with advertising exposure on spaceweather.com. Email:
dr.tony.phillips@gmail.com
  September 16, 2014 -Solar activity is low. However, sunspots AR2157, AR2158 and AR2164 have 'beta-gamma' magnetic fields that harbor energy for significant eruptions. NOAA forecasters estimate a 50% chance of M-class flares on Sept. 16th. September 15, 2014 -Last-quarter Moon (exactly last-quarter at 10:05 p.m. EDT). The Moon rises around midnight tonight under the horn-tips of Taurus. It stands high in the south over Orion by Tuesday's dawn. -Another CME is en route to Earth. It was launched in our direction three days ago by the eruption of a magnetic filament near the center of the solar disk. The impact won't be as effective as the double-whammy of Sept. 12th, described below. Nevertheless, NOAA forecasters estimate a 40% chance of polar geomagnetic storms on Sept. 16th when the CME arrives. High-latitude sky watchers should remain alert for auroras. -At the peak of the September 11-12 storm, observers in Scandinavia witnessed stunning coronas and even a rare aurora-rainbow ensemble. A hint of auroras were even photographed in Arizona. The below image was taken by Kjetil Skogli of Tromsø Norway. His comments: "During a workshop I had for group of photographers we experienced a rare combination late evening. Northern lights above a rainbow. It was rainy in the lower part of a valley and we had the moon behind us. The rainbow stayed there for hours. For me this was the third time I experienced this during my 11 years as a Aurora photographer Every time it has been in the same valley." Link to image: http://spaceweathergallery.com/indiv...load_id=101791 September 14, 2014 -Sunspot AR2158, the source of last week's powerful X-flare, is decaying as it turns away from Earth. This is decreasing the chance of another geoeffective explosion. NOAA forecasters put the odds of an X-flare today at a waning 25%. -While the web site Spaceweather.com was down during the most intense geomagnetic storm of the year, the webmaster shook off the stress by going outside ... and launching a space weather probe. Carried aloft by a helium balloon, the probe was prepared and released by the students of Earth to Sky Calculus just as the planetary K-index hit 7during the waning hours of Sept. 12th. Inside the balloon's payload, there was a high-energy radiation sensor, a cryogenic thermometer, multiple GPS altimeters and trackers, and three cameras to record the flight. The launch was the latest in an ongoing series of suborbital balloon flights to measure the effect of stormy space weather on Earth's atmosphere from ground level to the stratosphere. Soon, the group will release an entire year's worth of data of interest to commercial aviation and space tourism. After a 2.5 hour flight, the payload has parachuted back to Earth and landed in the Inyo Mountains of central California. A student team will recover the payload and its sensors this weekend.  September 13, 2014 -As predicted, a pair of CMEs hit Earth's magnetic field in quick succession on Sept. 11th and 12th. The result was a G3-class geomagnetic storm, the most intense of the year so far. At the peak of the storm on Sept 12-13, bright auroras ringed the Arctic Circle and spilled down over several northern-tier US states. The sky over Maine exploded in a rainbow of colors. "I took the picture from Casco, Maine, facing north towards the Presidential Range in New Hampshire," says photographer John Stetson. "Red, purple, green, blue--all the colors were there!" The storm is subsiding now. Nevertheless, high-latitude sky watchers should remain alert for auroras. NOAA forecasters estimate a whopping 90% chance of additional polar geomagetic activity on Sept. 13th as Earth passes through the wake of the double CME. Sky watchers should remain alert for auroras. -On Sept. 12th, Spaceweather.com was offline for more than 12 hours during the most intense geomagnetic storm of the year. Ironically, the outage was not caused by solar activity. A hardware failure in the network of our Internet service provider brought the web site down at the worst possible time. Webmaster Dr. Tony Phillips apologizes to our readers, alert subscribers, and advertisers for the outage. We are taking steps to make sure this cannot happen again.  September 12, 2014 -The first of two CMEs expected to hit Earth's magnetic field on Sept. 12th has arrived, and a minor (G1-class) geomagnetic storm is underway as a result of the impact. The second and potentially more powerful CME is still en route. NOAA forecasters say geomagnetic storming could become strong (G3-class) during the late hours of Sept. 12th and Sept 13th after the second CME arrives. -Observers in Canada and several northern-tier US states saw mild green auroras after the first impact. Matthew Moses sends this picture from Munger, MN. "It was a somewhat subdued display," says Moses. "I am looking forward to see what the next CME treats us to." The next CME, now only hours away, was launched by an X-class flare, so it is potent. However, not every potent CME produces a potent geomagnetic storm. It all depends on the inner magnetic architecture of the CME, which is unknown until the CME actually arrives. NOAA forecasters are estimating a 45% chance that strong magnetic disturbances will reach mid-latitudes on Sept 13--almost like a coin toss. Sky watchers should remain alert for auroras. September 11, 2014 -A pair of CMEs is heading for Earth. The two solar storm clouds were launched on Sept. 9th and 10th by strong explosions in the magnetic canopy of sunspot AR2158. NOAA forecasters estimate a nearly 80% chance of polar geomagnetic storms on Sept. 12th when the first of the two CMEs arrives. Auroras are in the offing, possibly visible at mid-latitudes before the weekend. -Sunspot AR2158 erupted on Sept. 10th at 17:46 UT, producing an X1.6-class solar flare. A flash of ultraviolet radiation from the explosion ionized the upper layers of Earth's atmosphere, disturbing HF radio communications for more than an hour. More importantly, the explosion hurled a CME directly toward Earth. The Solar and Heliospheric Observatory photographed the expanding cloud. Radio emissions from shock waves at the leading edge of the CME suggest that the cloud tore through the sun's atmosphere at speeds as high as 3750 km/s. That would make this a very fast moving storm, and likely to reach Earth before the weekend. Auroras are definitely in the offing. -The X-flare of Sept 10th caused a radio blackout on Earth. Ironically, it also caused a blast of radio noise. Radio astronomers and hams in the Americas and across the Pacific Ocean heard static roaring from the loudspeakers of their shortwave receivers. "It was absolutely howling," reports Thomas Ashcraft, who sends this 3-minute recording from his amateur radio observatory in rural New Mexico. "This is what I heard at the onset of the flare," he explains. "By the time the flare peaked, it became almost too intense for my ears." Advice: Listen to the sound file using stereo headphones. The two channels correspond to two radio frequencies--22 and 23 MHz. Link: http://www.spaceweather.com/images20...shcraft_02.mp3 Radio emissions like these are caused by shock waves in the sun's atmosphere. Looking at the CME pictured in the news item above, it is easy to imagine how the fast-moving cloud would spawn shock waves in the atmosphere overlying sunspot AR2158. Those shock waves triggered plasma instabilities which, in turn, generated the shortwave radio emissions. More radio bursts may be in the offing. Sunspots AR2157 and AR2158 have unstable magnetic fields that harboor energy for strong explosions. NOAA forecasters estimate a 40% chance of X-class flares and a whopping 85% chance of M-flares on Sept. 11th.   September 10, 2014 -The gibbous Moon, still big, rises in the east in late twilight. Look well above it for the bottom corner of the up-tilted Great Square of Pegasus. -NOAA forecasters have issued a geomagnetic storm warning for Sept. 12th when a CME (described below) is expected to deliver a glancing but potent blow to Earth's magnetic field. The storm could reach moderate intensity (G2-class) with auroras visible across northern-tier US states such as Maine, Michigan, and Minnnesota. -Yesterday, the magnetic canopy of sunspot AR2158 erupted, producing an explosion that lasted more than 6 hours. The flare peaked on Sept. 9th at 00:30 UT with a classification of M4 on the Richter Scale of Solar Flares. Long-duration flares tend to produce bright CMEs, and this one was no exception. Coronagraphs onboard the Solar and Heliospheric Observatory observed a CME racing out of the blast site at nearly 1,000 km/s (2.2 million mph). Most of the storm cloud is heading north of the sun-Earth line, but not all. A fraction of the CME will deliver a glancing blow to Earth's magnetic field during the early hours of Sept. 12th. In the past few weeks, glancing blows from minor CMEs have sparked beautiful auroras around the Arctic Circle. This CME could spark even better displays. NOAA forecasters estimate a 79% (not a typo: 79%) chance of polar geomagnetic storming on Sept. 12th.  September 9, 2014 -Arcturus is the bright star fairly high due west at nightfall. It's an orange giant 37 light-years away. Off to its right in the northwest is the Big Dipper, most of whose stars are about 80 light-years away. -Reports are circulating of a meteorite strike in Nicaragua on Sunday, Sept. 7th. Because the timing coincides with the flyby of asteroid 2014 RC, some reporters have suggested a link. We are skeptical. The crater outside Managua looks more like it was dug by a backhoe than excavated by a high-energy meteoritic explosion. Also, no streak of light corresponding to a meteor was actually observed. Stay tuned for updates on this developing story. http://www.bbc.com/news/world-latin-america-29106843 -The northern autumnal equinox is less than two weeks away. That makes tonight's full Moon the Harvest Moon, the full Moon closest to the beginning of Fall. Ruslan Merzlyakov sends this picture of the pumpkin-colored orb from Nykøbing Mors, Denmark: "It was a very beautiful moonrise!" he says. The name "Harvest Moon" harkens back to a bygone era. Before the days of electric lights, farmers relied on moonlight to harvest crops which ripened all at once in autumn. They couldn't afford to stop working at sunset, so "harvest moonlight" was essential to their operations. The flow of electricity has made the Moon obsolete as a source of practical illumination, but not as an object of beauty. Step outside tonight at sunset, look east and enjoy the view.  September 8, 2014 -NOAA forecasters have raised the odds of an X-class solar flare today to 30%. Two sunspots turning toward Earth pose a threat for such eruptions: AR2157 and AR2158. Both are capable of strong geoeffective activity. -On Sunday, Sept. 7th, house-sized asteroid 2014 RC flew past Earth. There was no danger of a collision, but the space rock was close. It sailed just underneath Earth's belt of geeosynchronous satellites and about 40,000 km over New Zealand. Using robotic telescope in Australia, a team of astronomers led by Ernesto Guido photographed 2014 RC zipping through the southern constellation Phoenix at 10 km/s (22,000 mph). 2014 RC came from the asteroid belt just beyond the orbit of Mars. According to NASA, "2014 RC will return to our planet's neighborhood in the future. The asteroid's future motion will be closely monitored, but no future threatening Earth encounters have been identified."  September 7, 2014 -Look for bright Vega passing your zenith in late twilight, if you live in the world's mid-northern latitudes. Vega goes right through your zenith if you're at latitude 39° north (near Baltimore, Kansas City, Lake Tahoe, Sendai, Beijing, Athens, Lisbon). How closely can you judge this? -According to NOAA analysts, a CME hit Earth's magnetic field on Sept. 6th at 1525 UT. However, the impact was weak and did not spark geomagnetic storms. September 6, 2014 -This is International Observe the Moon night! Zoom in on the map http://observethemoonnight.org/ to find an event near you. Or set up your own telescope for the public, and add your event to the map so people can find you! The Moon is waxing gibbous, two days from full. (Just make sure it'll be in view from your site when you tell people to come!) Also, look to the right of the Moon, by a little more than a fist-width at arm's length, for two faintish (3rd-magnitude) stars: Alpha and Beta Capricorni, one above the other. Alpha is the one on top. With sharp vision, you can barely see that it's double. Binoculars resolve it easily. -NOAA forecasters estimate a 25% chance of polar geomagnetic storms on Sept. 6th when a CME is expected to deliver a glancing blow to Earth's magnetic field. High-latitude sky watchers should be alert for auroras. September 5, 2014 -Saturn, Mars, Delta (δ) Scorpii, and Antares form an equally-spaced ragged line in the southwest at dusk, as shown at right. Delta Scorpii used to be a bit dimmer than Beta above it. Then in July 2000 it doubled in brightness. It has remained bright, with slow fluctuations, ever since. Look high above the Moon this evening for Altair. -This Sunday, a house-sized asteroid named "2014 RC" will fly through the Earth-Moon system almost inside the orbit of geosynchronous satellites. At closest approach, Sept. 7th at 18:18 UTC, the 20-meter-wide space rock will pass just 40,000 km over New Zealand. This diagram from NASA shows the geometry of the encounter. There is no danger of a collision with Earth. Asteroid 2014 RC was discovered on the night of August 31 by the Catalina Sky Survey near Tucson, Arizona, and independently detected the next night by the Pan-STARRS 1 telescope, located on the summit of Haleakalā on Maui, Hawaii. Follow-up observations quickly confirmed the orbit of 2014 RC: it comes from just beyond the orbit of Mars. The close appproach of this space rock offers researchers an opportunity for point-blank studies of a near-Earth asteroid. Even amateur astronomers will be able to track it. Around the time of closest approach, it will brighten to magnitude +11.5 as it zips through the constellation Pisces. This means it will be invisible to the naked eye but a relatively easy target for backyard telescopes equipped with CCD cameras. According to NASA, "[the orbit of 2014 RC] will bring it back to our planet's neighborhood in the future. The asteroid's future motion will be closely monitored, but no future threatening Earth encounters have been identified." If you want to try and see this asteroid for yourself, use the following link for tracking information: http://www.minorplanetcenter.net/db_...RC&commit=Show   September 4, 2014 -In Friday's dawn, use binoculars to help pick up Venus just above the eastern horizon about 30 minutes before sunrise. It's far to the lower left of Jupiter. Can you make out Regulus, less than a hundredth as bright, within 1° of Venus? -On Sept. 2nd, an enormous filament of dark plasma, which had been snaking across the face of the sun for days, became unstable and erupted. NASA's Solar Dynamics Observatory recorded the event (movies: #1, #2). A CME emerging from the blast site appears to have an Earth-directed component. According to NOAA analysts, the CME could deliver a glancing blow to Earth's magnetic field on Sept. 6th. This is not a particularly fast or powerful CME. Nevertheless, the coming impact could spark auroras. The last two minor CMEs that struck Earth in late August triggered beautiful displays of Northern and Southern Lights. The reason: it's aurora season. High-latitude sky watchers should prepare for Sept. 6th. September 3, 2014 -For days, amateur astronomers around the world have been monitoring an enormous filament of dark plasma snaking across the face of the sun. Yesterday it erupted. A movie from NASA's Solar Dynamics Observatory seems to show debris from the blast hurtling in the general direction of Earth. Stay tuned for coronagraph data, which could confirm or refute an Earth-directed CME. September 2, 2014 -The Great Square of Pegasus is well up in the east as soon as nightfall is complete. It's larger than your fist at arm's length and currently stands on one corner. Seen from your latitude at your time, how close is its balance to being perfect? -A sunspot located just behind the sun's northeastern limb exploded yesterday, Sept. 1st @ 1105 UT, producing "a significant solar flare," according to NOAA analysts. NASA's STEREO-B spacecraft, stationed over the farside of the sun, recorded the extreme ultraviolet flash. A fast CME emerged from the blast site traveling approximately 2000 km/s (4.5 million mph). The flare also produced strong radio bursts and a farside solar proton storm. Only the intervening limb of the sun prevented Earth effects. When flares occur on the Earthside of the sun, we classify them according to their X-ray intensity: C (weak), M (medium), or X (strong). Farside explosions, however, cannot be precisely classified because none of the spacecraft stationed over the farside of the sun are equipped with X-ray sensors. Based on the appearance of the flare at UV wavelengths, plus other factors such as the CME and radiation storm, we would guess that this was a strong-M or X-class event. Soon, the source of the explosion will reveal itself as solar rotation carries it up and over the sun's NE limb. Earth-directed solar activity could be just a few days away.   September 1, 2014 -First-quarter Moon this evening and Tuesday evening (exactly first quarter at 7:11 a.m. Eastern Daylight Time Tuesday morning). It's passing over Scorpius, as shown below. -After a long, long summer day, Arctic skies are darkening again, and in the sunset observers are seeing rays of green in the twilight blue. Frank Olsen of Sortland, Norway, took this picture at sunset on Aug. 31st. "I went out last night to catch the sunset--but mostly the auroras," says Olsen. "Even before it was dark, the Northern Lights made an appearance." More lights are in the offing. NOAA forecasters estimate a 20% of polar geomagnetic storms during the next 24 hours. The odds of Arctic auroras are higher, however, because it doesn't take a full-fledged storm to turn the twilight green at polar latitudes.  August 31, 2014 -Spot the Moon at dusk with Saturn to its right and Mars to its lower left (for North America). -As the stars come out this week, the first you see may be Arcturus shining high in the west. As the sky gets a little darker, look to its right for the Big Dipper scooping down in the northwest. -As northern summer comes to a close, electrical storms are rumbling across the USA. After nightfall, red sprites can be seen dancing across the cloudtops. On Aug. 20th, Tom A. Warner photographed these speciments above New Underwood, South Dakota. "On the night of Aug 20th, intense storms developed in north central South Dakota," says Warner. "Skies cleared out to the west and offered a chance to capture some sprites from the northern activity." He saw not only sprites, but also green-glowing gravity waves. The waves are, literally, the ripple effect of a powerful thunderstorm on the mesosphere some 80 km above Earth's surface. From space, these waves look like a giant atmospheric bull's eye. From the ground, they appear to be green ripples in the sky, as shown in Warner's images. Left to themselves, gravity waves would be invisible to the human eye. We see them, however, because they are colored green by an aurora-like phenomenon called "airglow." Airglow is caused by an assortment of chemical reactions in the upper atmosphere driven mainly by solar ultraviolet radiation. Gravity waves rippling away from the central axis of a thunderstorm cause temperature and density perturbations in the upper atmosphere. Speaking simplistically, those perturbations alter the chemical reaction rates of airglow, leading to more-bright or less-bright bands depending on whether the rates are boosted or diminished, respectively. Inhabiting the upper reaches of Earth's atmosphere alongside meteors, noctilucent clouds and some auroras, sprites and mesospheric gravity waves are true space weather phenomena. Now is a good time to see them.  August 30, 2014 -The waxing crescent Moon now shines closer to Saturn and Mars, as shown above. Can you see little Alpha Librae in the middle of the narrow triangle they make? -In mid-November, ESA's Rosetta spacecraft will make history by dropping a probe onto the surface of a comet. Bristling with 10 sensors including a camera, the Philae lander will touchdown somewhere on the rugged double-lobed core of comet 67P/Churyumov-Gerasimenko. August 29, 2014 -The Moon is coming back into the evening sky. Look for the waxing crescent low in the west-southwest in twilight, as shown at lower right. Can you make out Spica twinkling beneath it? Binoculars help. Far to their upper left are Saturn and Mars. -"After a long summer without stars, the Northern Lights have finally returned," reports Fredrik Broms of Tromsø, Norway (70 deg N latitude). "Last night's display was so strong that, although constellations such as Cassiopeia are still only to be made out very faintly on the blue night sky, the auroras shimmered and danced in an explosion of colors!" This is what he saw almost directly overhead around local midnight on August 28th: -The twilight display was sparked by a pair of CME impacts on August 27th. As Earth passed through the wake of the storm clouds, the interplanetary magnetic field (IMF) around Earth tipped south. This opened a crack in our planet's magnetosphere; solar wind poured in to fuel a light show that lasted for nearly three days and nights. NOAA forecasters estimate a 20% chance of polar geomagnetic storms on Aug. 29th as CME effects wane. Arctic sky watchers should remain alert for green in the twilight.  August 28, 2014 -The Great Square of Pegasus is now well up in the east as soon as nightfall is complete. It's larger than your fist at arm's length and currently stands on one corner. Seen from your latitude at your time, how close is the balance to perfect? -Go outside just after sunset and look southwest. Something there will make you do a double-take. Mars and Saturn have converged alongside the second brightest star in Libra to form a pretty twilight triangle. "It was an amazing triangle," says photographer Marek Nikodem of Szubin, Poland. The planets are labeled in Nikodem's photo, but that star is not. That's because its name wouldn't fit. The second brightest star in Libra is Zubenelgenubi. Pronounced "zoo-BEN-el-je-NEW-bee," it is a double star 77 light years from Earth easily split by binoculars or a small backyard telescope. Soon, the threesome will become a foursome. The crescent Moon will pass through the triangle on August 30th and 31st. On those evenings, in the time it takes to scan your telescope around a small patch of sky, you can see a double star, the rings of Saturn, the red disk of Mars, and the cratered landscape of the Moon. Mark your calendar!  August 27, 2014 -Arctic sky watchers should be alert for auroras. Currently, solar wind conditions favor geomagnetic activity at high-latitudes, sparking Northern Lights bright enough to shine through the late-summer twilight. Mike Theiss sends this picture from the east coast of Iceland. "The lights were incredible," says Theiss. "They changed intensity on and off for about 3 hours on Aug. 27th." These auroras signal the arrival of a CME launched toward Earth on Aug. 22nd. As NOAA analysts predicted, the solar wind speed did not change much in response to the CME. However, the storm cloud contained a south-pointing magnetic field that opened a crack in Earth's magnetosphere. Solar wind is pouring in to fuel the ongoing display. -orking over the weekend, Rosetta mission planners and scientists narrowed a list of 10 candidate landing sites to only 5. They are circled in this image of the core of 67P/Churyumov-Gerasimenko. In mid-November, Rosetta's Philae lander will attempt to touch down in one of these locations--the first time humankind has ever landed a probe on the core of a comet. The candidate sites are distributed as follows: three (I, B and J) on the comet's smaller lobe and two (A and C) on the larger. The comet's canyon-like neck has been excluded. All of the candidate landing sites provide at least six hours of daylight per comet rotation and offer some flat terrain. According to the ESA, every site has the potential for unique scientific discoveries by the lander's 10 instruments. A full discussion of each site may be found in this ESA press release. By September 14th, the five candidates will have been assessed and ranked, leading to the selection of a primary landing site, for which a fully detailed strategy for the landing operations will be developed, along with a backup.   August 26, 2014 -If you're in the Earth's mid-northern latitudes, bright Vega shines near your zenith just as night becomes fully dark. Whenever you see Vega most nearly straight up, you know that Sagittarius, with its deep-sky riches, is at its highest in the south. -Yesterday, active sunspot AR2148 erupted twice, producing a rapidfire pair of M-class solar flares (M2 @ 1511 UT and M3 @ 2021 UT). The Solar and Heliospheric Observatory recorded a corresponding pair of CMEs emerging from the blast site. According to NOAA analysts, the first CME does not have an Earth-directed component. The second CME looks even less Earth-directed than the first. In short, they missed. More eruptions may be in the offing. Sunspots AR2146 and AR2149 both have complex magnetic fields that harbor energy for strong flares. NOAA forecasters estimate a 55% chance of M-class flares and 10% chance of X-flares on August 26th.  August 25, 2014 -Have you ever wondered what a lunchbox suspended 112,000 feet above Earth's surface would look like? The answer is, this: -This is actually a Space Weather Buoy--a lunchbox containing a cosmic ray detector, cameras, GPS trackers, a thermometer and other sensors. It flew to the stratosphere on August 22nd tethered to a suborbital helium balloon. In collaboration with Spaceweather.com, the students of Earth to Sky Calculus have been launching these buoys on a regular basis to study the effect of solar activity on Earth's upper atmosphere. Soon, they will release results from a year-long campaign covering altitudes of interest to aviation, space tourism, and ozone research. The students wish to thank Eden Botanicals for sponsoring the August 22nd flight. (Note their logo on the corner of the payload.) This was the student group's 58th successful launch--almost all paid for by a combination of donations and commercial advertising. If you would like your own logo sent to the stratosphere, visit the spaceweather.com website and contact dr.tony.phillips@earthlink.net .  August 24, 2014 -Mars and Saturn are closest together this evening and Monday evening, separated by 3.4°. They're the same brightness but not the same color. And compare Mars's color to that of its rival Antares, not quite as bright, in Scorpius about 20° to the left. (See the last illustration below.) Mars will pass Antares by just 3° in late September. -On Saturday morning, Aug. 23rd, Venus, Jupiter and the crescent Moon converged to form a bright triangle in the pre-dawn sky. On Sunday morning the triangle dispersed. Pete Lawrence photographed the break-up from the seashore in Selsey, West Sussex, UK. "Venus and Jupiter were easy targets this morning, but the thin (4%) crescent Moon was a different matter!" says Lawrence. "It was almost invisible in the red glow of sunrise." (can't find the moon in the image below? http://puu.sh/b5Ol2/77db7e425b.jpg ) -Did you oversleep on Saturday? No problem. Another "celestial triangle" is in the offing. Right now the Moon is passing the sun en route to the evening sky. On August 31st it will join Mars and Saturn in the constellation Libra. Visible after sunset, the new triangle won't be quite as luminous as the old one, because Mars + Saturn is not as bright as Venus + Jupiter, but the formaton will still be very pretty.  August 23, 2014 [left]-August is prime Milky Way time. After dark, the Milky Way runs from Sagittarius and Scorpius in the south-southwest, up and left across Aquila and through the big Summer Triangle very high in the southeast and east, and on down through Cassiopeia to Perseus rising low in the north-northeast. -Europe's Rosetta probe has been at Comet 67P/Churyumov-Gerasimenko for two weeks, taking close-up pictures and making measurements of the comet's strange landscape. According to ESA, researchers now have the data they need to start picking a landing site. This weekend, mission planners will meet to consider 10 candidate locations, with the goal of narrowing the list to 5 by Monday. August 22, 2014 -Altair is the brightest star shining halfway up the southeastern sky after nightfall. Look to its left, by a little more than a fist at arm's length, for the dim but distinctive constellation Delphinus, the Dolphin. He's leaping leftward, just below the Milky Way. -In Saturday's dawn, the thin waning crescent Moon forms an elegant triangle with Jupiter and Venus low in the east, as shown at lower right. -Visually, the CME that struck Earth's magnetic field on August 19th was dim and unimpressive. The auroras it produced were magnificent. "For the first time in my life, I saw the Northern Lights," says Tadas Janušonis who sends this photo from Vabalninkas, Lithuania. "It is a very rare phenomenon here in Lithuania," he says, "but the August 19th impact was strong enough to [produce] them." Actually, the impact was weak. A CME like this one hits with a mechanical pressure of no more than 1 or 2 nanoPascals. That's 1 or 2 billionths of a Pascal - softer than a baby's breath. The reason it was so effective had more to do with its inner magnetic structure. This CME contained a region of south-pointing magnetism that partially canceled Earth's north-pointing magnetic field, opening a crack in the magnetosphere. Solar wind poured and fueled the display.   August 21, 2014 -As soon as the stars come out, the Great Square of Pegasus stands low in the east. It's balancing on one corner, and your fist at arm's length fits inside it. It rises higher through the evening and floats highest overhead around 2 or 3 a.m. -For the past month, the sun has been mostly quiet with only a smattering of C- and B-class solar flares. As flares go, these are puny. In fact, when the sun is crackling with flares no stronger than B-class, we often say that "solar activity is very low." But is it, really? A B-class solar flare packs a bigger punch than is generally supposed. Consider this specimen photographed by Harald Paleske of Weißenfels/ OT Langendorf, Germany, on August 17th. "This was a B8-class flare in sunspot AR2144," says Paleske. "Despite poor seeing, I was able to capture a high-resolution view of the explosion using my 225mm Unigraph solartelescope." The violence frozen in these snapshots belies the idea that this was a weak explosion. And indeed it was not. A typical B-class solar flare releases as much energy as 100 million WWII atomic bombs. Only on the sun, which is itself a 1027 ton self-contained nuclear explosion, would such a blast be considered puny. So the next time you hear that the forecast calls for "low solar activity," remember ... everything is relative. Today's forecast, by the way, calls for low solar activity with only a 10% chance of M-class solar flares.  August 20, 2014 -A moderate (G2-class) geomagnetic storm that erupted following a CME strike on August 19th is subsiding now. At its peak, the storm sparked auroras around both poles visible from the ground and from space. Astronaut Reid Wiseman took this picture from the window of the International Space Station: "Never in my wildest dreams did I imagine this," tweeted Wiseman (@astro_reid). "Unbelievable." Around the Arctic Circle where the midnight sun has overwhelmed auroras since Spring, observers caught their first glimpse of Northern Lights in months "At one point a massive corona unfolded just over my head!" reports Alexander Kuznetsov from the Finnish Lapland. "It was a great season opener," added Pekka Hyytinen of Tampere, Finland. "I also caught a lightning strike in one of my photos." Solar wind conditions are unsettled but calming as Earth passes through the wake of the CME. NOAA forecasters estimate a waning 30% to 15% chance of more geomagnetic storms during the next 24 hours.  August 19, 2014 -If you're in the Earth's mid-northern latitudes, bright Vega passes close by your zenith just as night becomes fully dark. Whenever you see Vega at its closest to straight up, you know that Sagittarius, with its deep-sky riches, is at its highest in the south. -A minor CME hit Earth's magnetic field on August 19th at approximately 06:30 UT. The impact was not a strong one. Nevertheless, mild to moderate geomagnetic storms are possible at high latitudes as Earth moves through the CME's wake on August 19-20. -Set your alarm for dawn. Venus and Jupiter are putting on a fantastic show in the early morning sky. At daybreak on Tuesday, August 19, Marek Nikodem caught the planets rising over Szubin, Poland: "It was a beautiful celestial dawn," says Nikodem, "definitely worth waking up for." Following their 0.2o near-miss on Monday, August 18th, Venus and Jupiter are separating, but not too quickly. They'll remain in the same patch of sunrise sky for the rest of the week. A date of special interest is August 23rd when the crescent Moon joins the planets to form a must-see celestial triangle.  August 18, 2014 -Look northeast as soon as the stars come out for W-shaped Cassiopeia. In twilight it's not quite as high as the Big Dipper is in the northwest, but right after dark, Cassiopeia and the Dipper reach their balance point. Summer is nearing its end. -NOAA forecasters estimate a 30% chance of polar geomagnetic storms on August 18th when a faint CME is expected to strike Earth's magnetic field head-on. This is not a major event. Nevertheless, high-latitude sky watchers should be alert for auroras when the CME arrives. -This morning Venus and Jupiter converged in the pre-dawn sky for a spectacular conjunction. At closest aproach they were barely 0.2o apart. Didier Van Hellemont sends this picture from Les Estables, France. "I photographed Venus and Jupiter from Mount Mezenc, one of the higher points of the Auvergne region in France," says Van Hellemont. "The sky was so clear and beautiful. It was definitely worth the early wake-up call." The planets are separating now, but not too quickly. They will still be a beautiful pair for the rest of the week. A date of special interest is August 23rd when the crescent Moon joins the planets to form a bright celestial triangle in the eastern pre-dawn sky. Observing tips: Go outside 30 minutes before sunrise and look north-northeast. No telescope is required. Jupiter and Venus are bright enough to see with the naked eye even from light polluted cities. Try following the bright pair after the dawn sky begins to brighten. A tight conjunction of Venus and Jupiter framed by twilight blue is a great way to start the day.  August 17, 2014 -As dawn brightens on Monday morning, look for Jupiter and Venus having their very close conjunction low in the east-northeast, 0.2° or 0.3° apart, as shown below. The best view should be about 60 to 30 minutes before your local sunrise time. -The Moon is at last quarter (exact at 8:26 a.m. on the 17th EDT). It shines high in the southeast in early dawn on this date, with the Pleiades roughly a fist-width at arm's length to its left and a bit higher.  August 16, 2014 -The two brightest stars of summer are Vega, overhead right after dark, and Arcturus, shining in the west. Vega is a white-hot type-A star 25 light-years away. Arcturus is an orange-yellow-hot type-K giant 37 light-years distant. Their color difference is fairly clear to the unaided eye. Both are dozens of times more luminous than the Sun. -Set your alarm for dawn! Venus and Jupiter are converging for a spectacular conjunction in the early morning sky. Closest approach: August 18th. Video: https://www.youtube.com/watch?v=yK57BMj2Vj4 August 15, 2014 -For the next several mornings, look low in the east-northeast about 45 to 30 minutes before sunrise for Venus and Jupiter very close together. On Saturday morning, these two brightest planets are still 2° apart, as shown at right. They'll be closest on Monday morning the 18th: just 0.2° or 0.25° apart at the time of dawn for Europe, 0.3° by the time dawn reaches the Americas. -Solar activity has been low for more than month, and there are scant signs of change in the offing. Not one of the sunspots now crossing the solar disk poses a threat for strong eruptions. As a result, NOAA forecasters put the odds of an M- or X-class solar flare during the next 24 hours at no more than 1%. -On August 6th, Europe's Rosetta spacecraft rendezvoused with Comet 67P/Churyumov-Gerasimenko and began to fly alongside it. Seven days later, mission scientists released this spectacular view of the comet's double-lobed core. A closer look reveals many interesting features: While the comet's head (in the top half of the image) is scored with parallel linear features, the neck is peppered with boulders resting on a smooth underlying terrain. In comparison, the comet's body (lower half of the image) is jagged and dimpled by crater-like depressions. Now imagine this magnificent landscape ruptured by dozens of geysers spewing dust and gas into space. Future pictures may show exactly that. Rosetta will follow this comet for more than a year as it approaches the sun. In 2015, if not sooner, solar heating will activate the comet's icy core, creating a riot of activity the likes of which no spacecraft has ever seen before. Stay tuned for that. Full Res Image: http://www.esa.int/var/esa/storage/i...7_August_a.jpg   August 14, 2014 -Vega is almost overhead after dark. The brightest star in the southeast is Altair, nearly as bright. Altair is flagged by little Tarazed (3rd magnitude) a finger-width above it: an orange giant far in Altair's background. -Observers reporting to the International Meteor Organization say that Perseid meteor rates are still high, greater than 40 per hour on Aug. 13-14. This means Earth has not yet exited the debris stream of parent comet Swift-Tuttle. If it is dark where you live, go outside and look up. -Before the Perseid meteor shower began, forecasters worried that people might not see it due to the glare of a supermoon. This photo illustrates why the Perseids succeeded in spite of lunar interference; the shower is rich in fireballs. "This was the brightest Perseid I saw on the night of August 12/13," says photographer Pete Lawrence. "Visually, it was a stunner!" After the meteor exploded over Lawrence's home in Selsey, UK, a wispy trail of debris appeared where the meteor had been a split-second before. "I recorded it in the very next frame," he says. This is "meteor smoke," a sinuous cloud of microscopic cinders tracing the path of the incinerating fireball. The particles of meteor smoke disperse in Earth's upper atmosphere and, ultimately, become the seeds of noctilucent clouds. All meteors produce such smoke, but only the brightest fireballs create a lingering trail bright enough to see with the unaided eye. Light from the supermoon, ironically, helps us see meteor smoke, because reflected moonlight increases the visibility of smoky debris. As a result, the smoke may have been photographed more often than usual during the 2014 Perseids. -Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. On Aug. 13, 2014, the network reported 163 fireballs. (99 Perseids, 61 sporadics, 1 Northern Delta Aquarid, 1 Southern Delta Aquarid, 1 Southern Iota Aquarid)   August 13, 2014 -The waning gibbous Moon rises in the east just about at the end of twilight. Look above the Moon (or above where it's just about to rise) for the Great Square of Pegasus, larger than your fist at arm's length and standing on one corner. -Comet Siding Spring is about to fly historically close to Mars. The encounter could spark Martian auroras, a meteor shower, and other unpredictable effects. Whatever happens, NASA's fleet of Mars satellites will have a ringside seat. August 12, 2014 -Peak Perseid meteor night late tonight. But the Moon, just two days after full, compromises the view. -The annual Perseid meteor shower peaks tonight, Aug. 12-13, as Earth passes through a stream of debris from Comet Swift-Tuttle. Forecasters expect peak rates of 30 to 40 meteors per hour, less than usual because of the glare from the waning supermoon. Observing tips: To reduce the effects of moonlight, pick an observing site with clear, dry air. Also try watching the sky from the moonshadow of a tall building or other obstacle. Many Perseid fireballs will be visible in spite of the glare. [NASA chat] Unaffected by moonlight, the Canadian Meteor Orbit Radar (CMOR) is scanning the skies above North America for echoes from disintegrating meteoroids. The latest CMOR sky map shows strong activity from the constellation Perseus (PER). The Perseids are not alone. In the southern hemisphere, a cluster of lesser radiants is also active. Foremost among them is the Southern Delta Aquarids (SDA) probably caused by debris from Comet 96P/Machholz. Delta Aquarid fireballs will augment the Perseids south of the equator.  August 11, 2014 -Mars is pulling a little closer to Saturn every day. Spot them in the southwest at dusk; Mars is the one on the lower right. Tonight they're still 8° apart. Look farther to the lower right of Mars for twinkly Spica. -The full Moon of August 10th was as much as 14% bigger and 30% brighter than other full Moons of the year. Some say that makes it a supermoon. Others retort that it's really not as super as the media has made it out to be. Who's correct? Vesa Vauhkonen of Rautalampi, Finland, took a stab at settling the question with this side-by-side comparison. "I compared the normal full Moon of March 2014 with the Supermoon of Aug 2014," says Vauhkonen. "In individual images, the difference in size might be difficult to see, but putting them side by side makes the difference clear. I used the same photo settings for both images, so the scaling has no errors." Supermoons are possible because the Moon's orbit is not a circle, it is an ellipse. One side, perigee, is 50,000 km closer than the other, apogee. On August 10th the Moon became full just as it reached perigee, the point closest to Earth. This caused the Moon to appear authentically bigger and brighter than usual.  August 10, 2014 -Largest full Moon of the year, but not by much. Can you really detect any difference? The Moon is only 8% larger than average. -As the one-month anniversary of the "All-Quiet Event" approaches, the sun's global X-ray output is sinking again. Solar activity is very low. Only one sunspot (AR2135) poses a threat for significant flares, but it seems reluctant to erupt. -Tonight's full Moon is the biggest and brightest full Moon of the year. Astronomers call it a perigee moon; the popular term is "supermoon." Stephen Mudge photographed the bright orb rising over the Mormon temple in Brisbane, Queensland, on Aug. 10th. Supermoons are possible because the Moon's orbit is not a circle, it is an ellipse. One side, perigee, is 50,000 km closer than the other, apogee. Today the Moon becomes full just as it reaches perigee, the point closest to Earth. The perigee supermoon you see tonight is as much as 14% closer and 30% brighter than other full Moons of the year. Go outside at sunset, look east, and enjoy the super-moonlight!  August 9, 2014 -If you're in the Earth's mid-northern latitudes, bright Vega passes close by your zenith around 10 or 11 p.m. (depending on where you live east-west in your time zone). Wherever you are, Deneb always passes the zenith two hours after Vega. -Sunspot AR2135 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Like every other sunspot that has crossed the solar disk in the past month, however, AR2135 seems reluctant to erupt. Solar activity is low and will likely remain so for the rest of the weekend. -On Friday, August 8th, Europe's robotic cargo carrier, the "George Lemaitre," flew just 4 miles underneath the International Space Station. In Berlin, Germany, astrophotographer Thomas Becker recorded the close encounter. "I caught the two spacecraft over the Wilhelm-Foerster-Observatory in Berlin," says Becker. "Bright moonlight completed the scenery." Loaded with more than seven tons of fuel and supplies, the George Lemaitre (a.k.a. "ATV-5") is scheduled to dock with the ISS on Tuesday, Aug. 12th. Friday's preliminary flyby allowed mission controllers to test a suite of lasers and sensors that may be incorporated into the design of future European spacecraft. George Lemaitre, the man, was a 20th century Belgian astronomer and physicist credited with proposing the theory of the expansion of the universe. ATV-5, the fifth in Europe's series of Automated Transfer Vehicles for shuttling supplies to the ISS, was named in his honor. Track when the ISS will orbit over your head with http://heavens-above.com/  August 8, 2014 -Already you may see an occasional Perseid meteor if you keep an eye on the night sky. The shower's peak night is predicted for next Tuesday (August 12–13), but moonlight will compromise the view all week. Look northeast as the stars come out for W-shaped Cassiopeia. It's still not quite as high as the Big Dipper is in the northwest, but the two are on their way to their dusk balance point week by week. Get a preview of this by checking on them around 11 p.m. (depending on your location). -This Friday, Aug. 8th, the students of Earth to Sky Calculus will continue their ongoing campaign of high-altitude research with the launch of another Space Weather Radiation Buoy. The purpose of the research is to discover how solar activity affects the ozone layer and alters levels of radiation at altitudes of interest to aviation and space tourism. August 7, 2014 -Vega is the brightest star very high in the east after dusk, almost overhead. The brightest in the southeast is Altair, nearly as bright. Altair is flagged by little Tarazed (3rd magnitude) a finger-width above it: an orange giant far in Altair's background. -For the first time ever, a spacecraft from Earth is traveling alongside a comet. Yesterday, at the end of a 10 year and 6 billion km journey, the European Space Agency's Rosetta probe reached 67P/Churyumov-Gerasimenko. On approach, Rosetta's OSIRIS camera took this stunning picture of the comet's nucleus only 130 km away. The image clearly shows a range of features including boulders, craters and steep cliffs. As the ESA science team noted this morning, "choosing a landing site will not be easy." More close-up shots may be found here. Rosetta has reached the comet, but it is not in orbit yet. As the below video shows, the spacecraft will spend the next month maneuvering closer and closer to the comet's core. When Rosetta dscends to within about 30 km of the surface in early September, the comet's weak gravity will be able to capture the spacecraft into a final orbit.  August 6, 2014 -Antares is well to the lower right of the Moon this evening, as shown here. More than twice as far to the Moon's upper left shines Altair. -The European Space Agency's Rosetta probe has reached 67P/Churyumov-Gerasimenko and is maneuvering to go into orbit around the comet's core. This is an historic event. After Rosetta goes into orbit, it will follow the comet around the sun, observing its activity from point-blank range for more than a year. Moreover, in November, Rosetta will drop a lander onto the comet's strange surface. Today's events are being streamed live by the ESA. Link: http://sci.esa.int/rosetta/54457-ros...he-event-live/ -On Tuesday morning, August 5th, a SpaceX Falcon 9 rocket lifted off from Cape Canaveral carrying the AsiaSat 8 telecommunications satellite. About an hour and a half after the 4 AM launch, electric-blue clouds appeared over Orlando FL. "These clouds appeared just before sunrise," says photographer Mike Bartils. These are, essentially, man-made noctilucent clouds (NLCs). Water vapor in the exhaust of the rocket crystallized in the high atmosphere, creating an icy cloud that turned blue when it was hit by the rays of the morning sun. Years ago, space shuttle launches produced similar displays. Natural NLCs form around Earth's poles when water vapor in the mesosphere crystalizes around meteor smoke. Sometimes they spread as far south as Colorado and Utah, but rarely or never Florida. Electric-blue over the Sunshine State requires a rocket launch, and that's what happened today.   August 5, 2014 -Look below the Moon this evening for the red supergiant Antares, as shown at right. Around Antares and to its right are other stars of upper Scorpius. -Meteor activity is increasing as Earth plunges deeper into the debris stream of Comet Swift-Tuttle, source of the annual Perseid meteor shower. On the night of Aug 3-4, NASA cameras recorded more than a dozen Perseid fireballs over the USA. Counts are high even though the shower's peak is still more than a week away. To see for yourself, get away from city lights and look up during the dark hours before sunrise. -On Saturday night, August 2nd, NASA meteor cameras detected a fireball that exploded in a flash of light many times brighter than the Moon. It came not from the Perseid debris stream, but rather from the vicinity of the asteroid belt between Mars and Jupiter. "The meteoroid was about 15 inches in diameter and weighed close to 100 lbs," says Bill Cooke of NASA's Meteoroid Environment Office. "Travelling 47,000 miles per hour, it broke apart in a brilliant flash of light above the Alabama town of Henagar. Our cameras continued to track a large fragment until it disappeared 18 miles above Gaylesville, located near Lake Weiss close to the Georgia state line. At last sight, the fragment was still traveling at 11,000 miles per hour. Based on the meteor's speed, final altitude, and weak doppler radar signatures, we believe that this fireball produced small meteorites on the ground somewhere between Borden Springs, AL and Lake Weiss." The NASA Meteoroid Environment Office would like to hear from those in the area around Alabama's Lake Weiss who may have heard sonic booms or similar sounds around 10:20 PM Saturday night. Please contact Dr. Bill Cooke at william.j.cooke@nasa.gov with reports. Link to the movie: http://fireballs.ndc.nasa.gov/events...31914A_02A.avi  August 4, 2014 -This weekend, Jupiter and Mercury are in conjunction. Don't bother looking because the meeting takes place in the noontime sky. What human eyes cannot see, however, spacecraft can. Using an opaque disk to block the glare of the sun, the Solar and Heliospheric Observatory (SOHO) is monitoring the encounter. At closest approach on August 2nd, the two bright planets were less than 1o apart. If such an alignment occured at night, it would surely be headline news. At noon, its just spaceweather news.   August 3, 2014 -This weekend the ESA released a new image of Comet 67P/Churyumov-Gerasimenko as seen from the Rosetta probe only 1000 km away. It shows the rough surface of the comet's double nucleus in amazing detail: The photo was taken on Aug. 1st at 02:48 UTC by Rosetta's OSIRIS Narrow Angle Camera. The dark spot near image-center is an artifact from the onboard CCD. This new view heightens anticipation for August 6th when Rosetta reaches the comet and goes into orbit around it. Then we will see the strange double-core from point-blank range, and researchers can start to pick touchdown sites for Philae, a lander that will descend to the comet's surface in November.  August 2, 2014 -The Moon shines about midway between Spica and Mars this evening, as shown below (plotted for the middle of North America). -This weekend, Jupiter and Mercury are in conjunction. Don't bother looking because the meeting takes place in the noontime sky. What human eyes cannot see, however, spacecraft can. Using an opaque disk to block the glare of the sun, the Solar and Heliospheric Observatory (SOHO) is monitoring the encounter. At closest approach on August 2nd, the two bright planets will be less than 1o apart. If such an alignment occured at night, it would surely be headline news. At noon, its just spaceweather news.  August 1, 2014 -At dusk this evening, the Moon forms the lower-right end of a very long, curving line of celestial objects. Counting to the Moon's upper left, these are Spica, Mars, and Saturn, as shown here. -Today is Lammas Day or Lughnasadh, one of the four traditional "cross-quarter" days midway between the solstices and equinoxes. More or less. The actual midpoint between the June solstice and the September equinox this year comes at 2:40 a.m. August 7th Eastern Daylight Time (6:40 UT). That will be the exact center of (astronomical) summer. -ESA's Rosetta probe is now only five days away from a historic encounter with Comet 67P/Churyumov-Gerasimenko. If all goes as planned, Rosetta will become the first spacecraft to orbit a comet, follow it around the sun, and even drop a lander on its surface. Readers got a sneak preview yesterday when ESA released dramatic new images of the comet's core and atmosphere. The comet's atmosphere or "coma" (left), is a mixture of gas and dust slowly evaporating away from the sun-warmed core (right). At the moment, the coma is diffuse and relatively calm. That's because the comet is still far from the sun, about 544 million kilometers away in the cold dark space between Mars and Jupiter. A year from now this could change, however, as the comet swings by the sun only 185 million kilometers away. Increased solar heating will liberate jets of dust and high-speed streamers of gas, swelling the coma into something larger and much more dangerous to the spacecraft. Rosetta is meeting up with the comet now so that researchers can not only study how the comet warms up along its orbit and how activity develops, but also because it is much safer to learn how to operate in such a new environment when the activity is relatively low. Moreover, landing would be significantly more challenging next year when activity is expected to be much higher.  July 31, 2014 -In a really dark sky, the Milky Way now forms a magnificent arch high across the whole eastern sky after darkness is complete. It runs all the way from below Cassiopeia in the north-northeast, up and across Cygnus and the Summer Triangle high in the east, and down past the spout of the Sagittarius Teapot in the south. -On Oct. 19, 2014, Comet Siding Spring (C/2013 A1) will pass extremely close to Mars. For a while last year researchers thought the comet's core might strike the planet's surface. Now we know that it will be a near miss. Siding Spring will glide by Mars only 132,000 km away--about 1/3rd of the distance between Earth and the Moon. On July 28th, UK astrophotographer Damian Peach photographed the comet en route to Mars passing by the galaxy Fornax A. "This proved to be a rather fascinating conjunction due to the strange appearance of Fornax A," says Peach. "The various faint shells surrounding it are thought to have been caused by several galactic collisions in the remote past." Three months from now the comet will reach Mars. Although the comet's nucleus will not strike the planet, gas and dust spewing out of the comet's core will likely interact with the Martian atmosphere. There could be a meteor shower, auroras, and other effects that no one can predict. NASA's fleet of Mars spacecraft and rovers will record whatever happens.  July 30, 2014 -The two brightest stars of summer are Vega, just east of the zenith after dark, and Arcturus, less high toward the west. Both are zero magnitude. The next zero-magnitude star to make its appearance will be Capella. It doesn't emerge until the early-morning hours. Look for it low in the north-northeast after about 1 a.m. local time (depending on your location, especially your latitude). -As the sunspot number rebounds from a deep low in mid-July, the chance of flares is increasing, too. However, the biggest threat for a flare today might not be a sunspot at all. Instead, our attention turns to a long dark filament of magnetism. Astrophotograher Jack Newton photographed the structure on July 29th from his observatory in Osoyoos, British Columbia. Stretching more than 100,000 km from end to end, and filled with dense plasma, the sinuous filament is held aloft by solar magnetic fields. If it snaps or collapses and hits the stellar surface below, the result could be a Hyder flare--a type of explosion that does not require a sunspot. NOAA forecasters estimate an increasing 25% chance of M-flares and a small but non-negligible 5% chance of X-flares on July 30th.  July 29, 2014 -Vega is the brightest star very high in the east. Far down to its lower right shines Altair, almost as bright. Altair is flagged by little Tarazed (3rd magnitude) a finger-width above it, an orange giant far in Altair's background. -The European Space Agency's Rosetta spacecraft is now less than 2300 km from Comet 67P/Churyumov-Gerasimenko. In only 9 days, Rosetta will reach the comet's core and go into orbit around it. Latest images from the probe's navigation camera show a strangely-shaped nucleus that is coming into sharper focus day by day.  July 28, 2014 -Mars continues its eastward trek against the cosmic backdrop. Look southwest at dusk. You'll notice that it's now definitely closer to Saturn than Antares is. Mars is to Saturn's lower right; Antares is to Saturn's lower left. -NOAA forecasters estimate a 20% chance of polar geomagnetic storms today when Earth makes contact with a minor solar wind stream. Sky watchers around the darkening Arctic Circle should be alert for auroras. -Earth is entering a broad stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. Although the peak of the shower is not expected until August, meteors are already flitting acrosss the night sky. On July 27th, NASA cameras caught this Perseid fireball flying over New Mexico. Over the weekend, NASA detected a total of five Perseid fireballs, a "micro-flurry" that signals the beginning of the annual display. Normally the best time to watch would be during the shower's peak: August 11th through 13th. This year, however, the supermoon will cast an interfering glare across the nights of maximum activity, reducing visibility from 120 meteors per hour (the typical Perseid peak rate) to less than 30. Instead, late July-early August might be the best time to watch as Earth plunges deeper into the debris stream before the Moon becomes full. If you go out meteor watching in the nights ahead, you'll likely see another shower, too: the Southern Delta Aquariids. Produced by debris from Comet 96P/Machholz, this shower peaks on July 29-30 with 15 to 20 meteors per hour. This is considered to be a minor shower, but rich enough in fireballs to merit attention. NASA will stream the display from an observing site at the Marshall Space Flight Center in Alabama. Live video begins on July 29th at 9:30 pm EDT.  July 27, 2014 -Despite an uptick in the sunspot number, solar activity remains low. AR2121 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares, but so far the quiet sunspot seems dis-inclined to erupt. A significant flare this weekend would be a surprise. -What a difference 10 years can make. The Solar Max of 2014 has been mild, producing relatively few sunspots and meagre auroras. A decade ago, however, a much more potent Solar Max was underway. A strong solar storm on July 27, 2004, sparked Northern Lights as far south as the Anza-Borrego Desert of California. Photographer Dennis Mammana recalls the night: "It was ten years ago--during the pre-dawn hours of July 27, 2004--that the Anza-Borrego Desert of Southern California was bathed in the most unusual of light—that of the aurora borealis. On this morning it danced over so wide an area of the northern sky that it required four wide-angle images stitched carefully together to capture it all." "As the sky darkened the night before, solar data convinced me that we in the Desert Southwest might get a rare display of Northern Lights, so I aimed a camera north and set it to take one exposure every minute. From time to time I checked the camera's LCD screen to see if it had captured anything of interest. Then, just before 4 a.m., I discovered blue streaks across the image. 'What a lousy time for the sensor to crap out on me!', I thought. But as I scrolled through the previous images to learn where it went bad, I saw the blue streaks dancing gracefully across the scene. It was the Northern Lights!" "I hastily threw all my gear in the back of the Jeep and headed for an interesting foreground a couple of miles away. And the photo you see is the result--perhaps the only image of the northern lights with ocotillos in the foreground!" Mammana's recollection reminds us what a "good Solar Max" is really like. There is still hope, however, that the ongoing mini-Max might produce some good displays. Statistics of previous solar cycles show that the strongest geomagnetic storms tend to occur during the declining phase of solar cycles--in other words, just where we are now. There may yet be SoCal auroras in the offing before this Solar Max is done. July 26, 2014 -New Moon (exact at 6:42 p.m. EDT). Summer is hardly more than a third over, astronomically speaking. But already the Great Square of Pegasus, symbol of the coming fall, heaves up from behind the east-northeast horizon at dusk and climbs higher in the east through the evening. It's balancing on one corner. -The return of old sunspots AR2107 and AR2108 from the farside of the sun has failed to elevate solar activity. The two formerly-active regions decayed during their two week absence and are now little more than "sunspot corpses." Forecasters expect the quiet sun to remain quiet throughout the weekend. -Auroras were *not* in the forecast this weekend. Nevertheless, "they're baaaaaaack," reports Bob Conzemius, who saw the Northern Lights on July 26th over Grand Rapids, Minnesota: "It has been a pretty quiet summer in northern Minnesota for seeing auroras, so it was nice to see them again," says Conzemius. "I shot entirely within the city limits of Grand Rapids, starting from my front yard and ending at McKinney Lake as it was getting light at 4:00 AM CDT." The source of this unexpected display was a fluctuation in the interplanetary magnetic field. The IMF tipped south, opening a crack in Earth's magnetospere. Solar wind poured in and ignited the auroras.  July 25, 2014 -Mars and Spica shine in the southwest at nightfall. Mars keeps pulling farther away from Spica; they're now 6° apart. Saturn glows pale yellow to their upper left. Arcturus sparkles high to their upper right. -In the middle of Solar Max, the sun has slipped into a state that resembles Solar Minimum. Sunspot numbers are low; the sun's X-ray and radio output are depressed; and NOAA forecasters estimate a scant 1% chance of solar flares during the next 24 hours. The quiet could be disturbed during the weekend, however, by the expected return of two old sunspots currently transiting the farside of the sun. -The luminous tendrils of noctilucent clouds (NLCs) have been likened to "frozen lightning", slow-moving bolts of electric-blue that slowly zig-zag across the twilight sky during the months of Arctic summer. Last night photographer P-M Hedén witnessed a display over Hedesunda, Sweden, that suggested a different name: "They looked like 'veins of Heaven,'" he says. "I was really hoping for a good show like this because my children came along to watch," says Hedén. "We were not disappointed. From the beginning at 23:00 local time we saw noctilucent clouds all around the sky - amazing! Around 1 AM we had veins of Heaven both in the sky and reflected in the water."  July 24, 2014 -In a really dark sky, the Milky Way now forms a magnificent arch high across the whole eastern sky after darkness is complete. It runs all the way from below Cassiopeia in the north-northeast, up and across Cygnus and the Summer Triangle in the east, and down past the spout of the Sagittarius Teapot in the south. -This week, Jupiter is passing behind the sun. Normally solar interference would make it difficult for radio astronomers to pick up Jupiter's shortwave radio bursts. Because the sun is so quiet, however, Jupiter is still able to maake itself heard. "I was able to capture distinct narrow-band radio emissions from Jupiter on July 21st," reports Thomas Ashcraft of New Mexico. They are the sloping lines in this dynamic spectrum he recorded using a RadioJove Project dual dipole antenna. "At the time Jupiter was 6.3 Astronomical Units (585,621,586 miles) distant from Earth," he adds. "I think this is a neat observation because it means there is always the possibility of receiving Jupiter radio emissions here on Earth--even when the sun is in the way and Jupiter is very distant." Jupiter's radio storms are caused by natural radio lasers in the planet's magnetosphere that sweep past Earth as Jupiter rotates. Electrical currents flowing between Jupiter's upper atmosphere and the volcanic moon Io can boost these emissions to power levels easily detected by ham radio antennas on Earth. Jovian "S-bursts" and "L-bursts" mimic the sounds of woodpeckers, whales, and waves crashing on the beach.   July 23, 2014 -As dawn brightens on Thursday morning the 24th, spot Venus low in the east-northeast with the waning crescent Moon to its right and Mercury still to its lower left, as shown here. -Today is the second anniversary of a scary near-miss. On July 23, 2012, Earth narrowly evaded a powerful solar storm capable of knocking civilization back into the 19th century. The event confirms that "solar superstorms" are real, and the odds of impact may be higher than we think: 12% in the next 10 years http://science.nasa.gov/science-news...ul_superstorm/ -Last night, a bank of noctilucent clouds (NLCs) rippled across northern Europe. "They were stunning," reports Alex Lebedev, who witnessed the apparition from Kohtla-Järve, Ida-Virumaa, Estonia. "Viewing it by eye was even better than the photo," he says. NLCs are Earth's highest clouds. Seeded by "meteor smoke," they form at the edge of space 83 km above Earth's surface. When sunlight hits the tiny ice crystals that form around the meteor debris, the clouds glow electric blue. July is the best month to see NLCs. They favor the climate of summer because that is when water molecules, warmed by summer sunlight, are wafted up from the lower atmosphere to mix with the meteor smoke. That is also, ironically, when the upper atmosphere is coldest, allowing the ice crystals of NLCs to form. The natural habitat of noctilucent clouds is the Arctic Circle. In recent years, however, they have spread to lower latitudes with sightings as far south as Utah and Colorado. This will likely happen in 2014 as well.  July 22, 2014 -Vega is the brightest star very high in the east. Far down to its lower right shines Altair, almost as bright. Altair is flagged by little Tarazed a finger-width above it, an orange-giant star far in Altair's background. -Solar activity remains very low. There is only one sunspot (AR2119) on the Earth-facing side of the sun, and it has a simple magnetic field that poses no threat for strong explosions. NOAA forecasters estimate a scant 1% chance of M- or X-flares during the next 24 hours. -Some of us have seen the midnight sun. Even more have witnessed sundogs. But have many people have seen a mashup of the two--the elusive midnight sundog? On July 21-22, Stine Bratteberg photographed the combo from Bleik, Andøya, Norway. "These fantastic sundogs appeared near midnight on the last day of the summer Midnight Sun here in northern Norway," says Bratteberg. Sundogs, the rainbow-colored splashes of light on either side of the sun, are caused by sunlight striking ice crystals in the air. Plate-shaped crystals flutter down from the sky like leaves falling from trees. Aerodynamic forces align their flat sides parallel to the ground, and when sunlight hits a patch of well-aligned crystals at the right distance from the sun, voila!--a sundog. Bratteberg's photo also captured a faint midnight sun halo and a midnight upper tangent arc. You can see a lot of midnight atmospheric optics from the Arctic Circle. But not for much longer. As northern summer comes to an end, the midnight sun will fade and auroras will chase the sundogs into the darkening Arctic night.   July 21, 2014 -As dawn begins very early early Tuesday morning the 22nd, look for Aldebaran near the waning crescent Moon in the east as shown below. Can you catch the Hyades stars before dawn gets too bright? -The "All Quiet Event" is still underway. For the 6th day in a row, solar activity is extremely low, with weak solar wind, no flares, and a sunspot number near zero. NOAA forecasters put the odds of a significant flare today at no more than 1%. July 20, 2014 -Solar activity is extremely low. Nevertheless, space weather continues. High above thunderstorms in the American west, red sprites are dancing across the cloudtops, reaching up to the edge of space itself. Harald Edens photographed this specimen on July 18th from the Langmuir Laboratory for Atmospheric Research in New Mexico. "This colorful sprite occurred over a large thunderstorm system in northeast New Mexico and was visible to the naked eye," says Edens. "I took the picture using a Nikon D4s and a 50 mm f/2 lens at ISO 25600." Inhabiting the upper reaches of Earth's atmosphere alongside noctilucent clouds, meteors, and some auroras, sprites are a true space weather phenomenon. Some researchers believe they are linked to cosmic rays: subatomic particles from deep space striking the top of Earth's atmosphere produce secondary electrons that, in turn, could provide the spark that triggers sprites. Although sprites have been seen for at least a century, most scientists did not believe they existed until after 1989 when sprites were photographed by cameras onboard the space shuttle. Now "sprite chasers" regularly photograph the upward bolts from their own homes. Give it a try!   July 19, 2014 -Mars at dusk is still slightly less than 3° (two finger widths at arm's length) from Spica in the southwestern sky. But they're widening and sinking lower day by day. -For the 4th day in a row, solar activity is extremely low. Compared to the beginning of July, when sunspots were abundant, the sun's global X-ray output has dropped by a factor of ten. Moreover, on July 17th the sunspot number fell all the way to zero. We call it "the All Quiet Event." As July 19th unfolds, the sun is no longer completely blank. Three small sunspots are emerging, circled in this image from NASA's Solar Dynamics Observatory. These small sunspots are not about to break the quiet. None of them has the kind of complex magnetic field that harbors energy for strong flares. NOAA forecasters estimate the odds of a significant flare (M- or X-class) in the next 24 hours to be no more than 1%. Before July 17, 2014, the previous spotless day was August 14, 2011, a gap of nearly 3 years. What happened then provides context for what is happening now. Overall, 2011 was a year of relatively high solar activity with multiple X-flares; the spotless sun was just a temporary intermission. 2014 will probably be remembered the same way. Or not. Almost anything is possible because, as one pundit observes, "you just can't predict the sun."  July 18, 2014 -Last-quarter Moon (exact at 10:08 p.m. Eastern Daylight Time). The Moon rises around midnight tonight, shining in Pisces. -This week, solar activity has sharply declined. There is only one numbered sunspot on the Earth-facing side of the sun, and it is so small you might have trouble finding it. The sun today draws similarities to 2008-2009, where there were years of spotlessness when the sun plunged into the deepest solar minimum in a century. The resemblance, however, is only superficial. Deep inside the sun, the solar dynamo is still churning out knots of magnetism that should soon bob to the surface to make new sunspots. Solar Max is not finished, it's just miniature. Until the sunspots return, solar flares are unlikely. NOAA forecasters estimate the odds of an M-flare today to be no more than 1%.  July 17, 2014 -The Big Dipper, high in the northwest after dark, is beginning to turning around to "scoop up water" through the nights of summer and early fall. -The waning Moon, nearly at last quarter, rises around 11 or midnight and climbs high in the early-morning hours. Far in its background is Uranus, magnitude 5.8. -The European Space Agency's Rosetta probe is now less than 10,000 km from its target: 67P/Churyumov-Gerasimenko. Rosetta is expected to reach and begin orbiting the comet's nucleus on August 6th. Long-range images suggest that the comet is a contact binary. This could present some interesting challenges for Philae, the probe's lander, which is slated to touch down on the comet's surface in early November. A contact binary occurs when two celestial objects, such as asteroids or comets, slowly move towards each other until they are touching. The slow approach of the two means they will form a single-oddly shaped body, rather than rebounding of one another. Nine near-Earth objects are known to be contact binaries. However, it is estimated that as many as 15 per cent of all near-Earth asteroids more than 650 feet (200 metres) in size are actually contact binaries.  July 16, 2014 [left]-If you have a dark enough sky, the Milky Way now forms a magnificent arch high across the whole eastern sky after nightfall is complete. It runs all the way from below Cassiopeia in the north-northeast, up and across Cygnus and the Summer Triangle in the east, and down past the spout of the Sagittarius Teapot in the south. -Ten days ago, the sun was peppered with large spots. Now it is nearly blank. This image taken on July 15th by NASA's Solar Dynamics Observatory shows a solar disk almost completely devoid of dark cores. Long-time readers absorbing this image might be reminded of 2008-2009, years when the sun plunged into the deepest solar minimum in a century. The resemblance, however, is only superficial. Underneath the visible surface of the sun, the solar dynamo is still churning out knots of magnetism that will soon bob to the surface to make sunspots. Solar Max is not finished. For today, though, it has been paused. Solar activity is low, and NOAA forecasters put the odds of an X-class flare at less than 1%.  July 15, 2014 -Vega is the brightest star very high in the east. Far down to its lower right shines Altair, almost as bright. Look left of Altair by about a fist and a half at arm's length, and a little lower, for dim, compact Delphinus, the Dolphin. It's leaping in the lower edge of the Milky Way. -Frequent fliers who look out the window of their planes often see the shadow of the aircraft dipping in and out of clouds below. The interplay of light and shadow with water droplets in the clouds can produce colorful rings of light called "glories." On July 13th, Tony DeFreece saw a glory that was not a colorful ring, but rather a heart. "I was flying over Oregon when I looked out and saw this heart-shaped figure," he says. "It was one of those moments when the Universe aligns and takes your breath away." DeFreece suspects, probably correctly, that the shape of the clouds bent the usual circular glory into the heart-shaped apparition. Mystery solved? Not entirely. Glories are caused by sunlight reflected backwards from water droplets in clouds. Exactly how backscattering produces the colorful rings, however, is a mystery involving surface waves and multiple reflections within individual droplets. Each sighting is a lovely puzzle, so grab the window seat and keep an eye on the clouds below. -NASA's New Horizons spacecraft is only a year away from Pluto. Researchers are buzzing with anticipation as humankind prepares to encounter a new world for the first time in decades.  July 14, 2014 -The tail of Scorpius is low in the south after dark — how low depends on how far north you are. Look for the two stars especially close together in the tail. These are Lambda and fainter Upsilon Scorpii, Shaula and Lesath, known as the Cat's Eyes. They're canted at an angle. -They point west by nearly a fist-width toward Mu Scorpii, a much tighter pair known as the Little Cat's Eyes. Can you resolve Mu without using binoculars? -All week, Mercury remains almost the same distance to the lower left of bright Venus low in the dawn. The best view may be about 45 minutes before sunrise, depending on how clear the air is. -The odds of an Earth-directed solar flare are plummeting as sunspots AR2108 and AR2109 rotate over over the sun's western limb. The departure of these two active regions leaves the face of the sun almost blank. Solar activity should remain low for the next 24-48 hours.  July 13, 2014 -This is the evening when Mars shines closest to Spica. Look southwest at nightfall. They're 1.3° apart. Fiery Mars is the brighter one. -Last night another outbreak of noctilucent clouds appeared over Europe. Photographer Peter Rosén of Stockholm, Sweden, stitched together 24 exposures taken with a fisheye lens to produce a "Little Planet" projection. "The NLC display last night was just incredible and covered half of the sky with electric blue filaments," says Rosen. "Normaly the Moon would have stolen the show, but a night like this it looked quite lonely on the southern horizon." NLCs are Earth's highest clouds. Seeded by "meteor smoke," they form at the edge of space 83 km above Earth's surface. When sunlight hits the tiny ice crystals that make up these clouds, they glow electric blue. In the northern hemisphere, July is the best month to see them. NLCs appear during summer because that is when water molecules are wafted up from the lower atmosphere to mix with the meteor smoke. That is also, ironically, when the upper atmosphere is coldest, allowing the ice crystals of NLCs to form. The natural habitat of noctilucent clouds is the Arctic Circle. In recent years, however, they have spread to lower latitudes with sightings as far south as Utah and Colorado. This will likely happen in 2014 as well.  July 12, 2014 -Look far above the still-full Moon this evening, and a bit left, to spot Altair. Continue a similar distance in roughly the same direction, and there's brighter Vega. -Earth could receive a glancing blow from a CME on July 13th. It comes from a magnetic filament that erupted from the sun's northern hemisphere on July 9th and hurled part of itself into space. Minor geomagnetic storms are possible when the CME arrives. -Today's full Moon is a perigee "supermoon," as much as 14% closer and 30% brighter than other full moons of the year. John Stetson photographed the swollen orb setting over Sebago Lake, Maine, this morning just minutes after sunrise. "An inferior mirage appears in the foreground where the lake meets the shoreline," points out Stetson. This was just the first of three supermooons in a row. Two more are coming on August 10th and September 9th. -This week, the sun is peppered with big spots. In some places, you can see them even at midnight. "Here in Lofoten islands, north of the Arctic circle, the sun never sets," reports Therese van Nieuwenhoven, "so we can observe sunspots around the clock. "As we enjoyed the beautiful midnight Sun in the north above the sea, my husband was projecting the large sunspots on a white piece of paper," she explains. Earlier in the week, several of these sunspots posed a threat for strong flares, but now the odds of an explosion are declining. Only one of the decaying active regions (AR2108) still has an unstable 'beta-gamma' magnetic field. NOAA forecasters estimate a waning 60% chance of M-flares on July 12th.   July 11, 2014 -Mars and Spica form a striking pair in the southwestern sky at dusk! They're now just under 2° apart. On Sunday evening they'll be at their minimum separation, 1.3°. Watch them change day by day. -Full Moon tonight and Saturday night (exactly full at 7:25 a.m. Saturday morning Eastern Daylight Time.) This evening the Moon shines in northern Sagittarius. Tomorrow it's in western Capricornus. July 10, 2014 -Vega is the brightest star very high in the east these evenings. The brightest to its lower left is Deneb. Farther to Vega's lower right is Altair. These make up the big Summer Triangle. -Solar activity is low, but the quiet is unlikely to persist. There are three sunspots with unstable magnetic fields capable of strong eruptions: AR2108, AR2109, AR2113. NOAA forecasters estimate a 75% chance of M-flares and 15% chance of X-flares on July 10th. -After weeks of sightings over Europe, noctilucent clouds (NLCs) are spreading to North America. "A spectacular display emerged over the Edmonton area on July 8/9," reports Canadian photographer Mark Zalcik. "For awhile there were multiple zones of billow-type NLC, including the snake-like one in this photo."  July 9, 2014 -Yesterday, July 8th, Earth-orbiting satellites detected a strong M6-class solar flare. NASA's Solar Dynamics Observatory recorded the extreme ultraviolet flash. X-ray and UV radiation from the flare sent waves of ionization coursing through Earth's upper atmosphere. This briefly disturbed the propagation of shortwave radio transmissions around the dayside of our planet, especially over Europe and North America. Conditions have since returned to normal. The flare came as little surprise. A phalanx of large sunspots is crossing the solar disk, and forecasters have been predicting an explosion for more than a week. However, the source of the flare was unexpected. It came from a minor and seemingly harmless sunspot named AR2113. Appearances notwithstanding, AR2113 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. With this flare, AR2113 joins two other sunspots capable of potent activity: AR2108 and AR2109. NOAA forecasters estimate a 75% chance of M-flares and a 20% chance of X-flares on July 9th.  July 8, 2014 -The Moon's latest daily shift eastward brings it left of Saturn and upper right of Antares at nightfall. Closer below the Moon are Beta and Delta Scorpii (as seen from North America). -For the second day in a row, the odds of a powerful flare have increased. NOAA forecasters now estimate a 70% chance of M-flares and a 15% chance of X-flares on July 8th. The likely sources are sunspots AR2108 and AR2109; both have unstable "beta-gamma-delta" magnetic fields that harbor energy for eruptions. -This morning in Russia, the sunrise was electric-blue. Bright bands of noctilucent clouds zig-zagged like lightning across the twilight sky, continuing a two-day display that has delighted observers across northern Europe. Michael Zavyalov sends this picture taken July 8th from the city of Yaroslavl. "Another night with bright noctilucent clouds (NLCs) in Yaroslavl!" says Zavyalov. "We could even see their reflection in the water." NLCs are Earth's highest clouds. Seeded by "meteor smoke," they form at the edge of space 83 km above Earth's surface. When sunlight hits the tiny ice crystals that make up these clouds, they glow electric blue. In the northern hemisphere, July is the best month to see them. NLCs appear during summer because that is when water molecules are wafted up from the lower atmosphere to mix with the meteor smoke. That is also, ironically, when the upper atmosphere is coldest, allowing the ice crystals of NLCs to form. The natural habitat of noctilucent clouds is the Arctic Circle. In recent years, however, they have spread to lower latitudes with sightings as far south as Utah and Colorado. This will likely happen in 2014 as well. Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see blue-white tendrils zig-zagging across the sky, you may have spotted a noctilucent cloud.   July 7, 2014 -Now the waxing gibbous Moon shines closely under Saturn in the evening (for North America), as shown at right. For southern South America, the Moon occults Saturn. Timetables: http://www.lunar-occultations.com/io...0708saturn.htm -Another outbreak of noctilucent clouds is underway over Europe. Jim Henderson sends this picture from Torphins, 15 miles west of Aberdeen, Scotland. "This is the second time this summer we've seen extensive NLCs in Scotland," he says. "I took the picture using a Nikon D700 (f5.6) set at at ISO 500 for 3 seconds." High-latitude sky watchers, take note of those settings. July is the best month of the year for noctilucent clouds, and your chance to take a similar picture could be just hours away.   July 6, 2014 -The Moon this evening poses midway between Saturn at its left and the Mars-Spica pair at its right. The Moon is very much in the foreground, just 1.3 light-seconds from Earth. Mars is currently 8½ light-minutes away, Saturn is 78 light-minutes away, and Spica is 250 light-years in the background. -As wide as a World Cup football field, the biggest spacecraft ever built makes a impressive silhouette when it passes in front of the sun. Yesterday, Maximilian Teodorescu of Romania caught the winged shadow of the International Space Station in conjuncton with sunspots AR2104 and AR2107. "This is my first attempt to catch the station with a small-sensor camera at high magnification," he says. "I managed to catch the ISS in three frames." His wife Eliza was right beside him with her own camera and solar filter, and she caught it too. "The moment was all the more spectacular because the ISS path was almost parallel to the very numerous string of sunspots," she notes. One conjunction after another unfolded as their cameras rolled. With the sunspot number so high, now is a good time to catch ISS-sunspot conjunctions.   July 5, 2014 -First-quarter Moon. The half-lit Moon is quite close to Mars as seen from North America. The Moon occults (hides) Mars during daylight for Hawaii and at dusk or night in parts of Latin America. -The two most massive objects in the asteroid belt, dwarf planet Ceres and minor planet Vesta, are converging for a close encounter in the night sky on July 4th and 5th. Last night in Italy, Gianluca Masi used a remotely operated telescope to photograph the monster asteroids only 13 arcminutes apart--less than half the width of a full Moon. The line splitting the two is a terrestrial satellite. At closest approach on July 5th, the two asteroids will be only 10 arcminutes apart in the constellation Virgo. They are too dim to see with the unaided eye, but easy targets for binoculars and small telescopes. Observing tips are available from Sky and Telescope. Got clouds? You can watch the close encounter online. Choose between Gianluca Masi's Virtual Telescope Project (which begins July 5th at 4:00 p.m. EDT) or Slooh's webcast (July 3rd at 8 p.m. Eastern Daylight Time). Virtual Telescope Project: http://www.virtualtelescope.eu/2014/...n-5-july-2014/ Slooh: http://live.slooh.com/ Quite near the two asteroids on the sky, though utterly invisible, is NASA's Dawn spacecraft. Dawn recently finished visiting Vesta and is now en route to Ceres. The ion-propelled spacecraft will enter orbit around Ceres next March. Cameras on Dawn will resolve the pinprick of light you see this weekend into a full-fledged world of unknown wonders. Stay tuned for that!  July 4, 2014 -Out to watch fireworks? As you're waiting for twilight to end, spot the Moon in the west-southwest with Mars and Spica off to its left, as shown for July 4 here. High above them all shines brighter Arcturus. Saturn is farther left. -Ceres and Vesta at their closest. The two leading asteroids, currently magnitudes 8.5 and 7.2, appear closest together this evening and tomorrow evening, just 10 arcminutes apart. 1 Ceres is the largest asteroid, and 4 Vesta sometimes becomes the brightest. -Sky watchers in Europe are reporting an outburst of bright noctilucent clouds (NLCs). The display began at sunset on July 3rd, filling northern horizons with electric-blue ripples, swirls, and tendrils of light. Morten Ross sends this picture from Sandbukta, Norway. "An incredibly bright and widespread display - from northern horizon to zenith!" says Ross. "This is only the third night of July and its already much better than last year." Similar reports have come from France, Germany, Poland, the Netherlands, Scotland, Ireland, England and Belgium. Although most of the reports so far have come from Europe, the nights ahead could bring NLCs to North America as well.   July 3, 2014 -NOAA forecasters estimate a 50% chance of M-class solar flares today. The likely source would be big sunspot AR2104, which has a 'beta-gamma-delta' magnetic field that harbors energy for strong eruptions. -Yesterday morning at 2:56 AM PDT, NASA's Orbiting Carbon Observatory-2 (OCO-2) blasted into space from the Vandenberg AFB in California. After liftoff, the exhaust from the satellite's Delta II rocket glowed so brightly that Juan Perez was able to see it 500 miles away in Wittmann, Arizona. Now orbiting Earth, OCO-2 is set to begin a two-plus year mission to locate the sources and sinks of atmospheric carbon dioxide, the leading human-produced greenhouse gas responsible for global warming. The launch was from the west coast so the spacecraft could enter a polar orbit of the Earth, a flight path that will see it cross over the Arctic and Antarctic regions during each revolution and get a complete picture of the Earth. It will fly about 438 miles above the planet's surface to take its readings. While ground stations have been monitoring carbon dioxide concentrations for years, OCO-2 will be the first spacecraft to conduct a global-scale reading over several seasons. -The sunspot number, already high, ticked upward again today with the arrival of another large active region over the sun's eastern limb. Click to play a 24-hour movie from NASA's Solar Dynamics Observatory. The explosive potential of this new sunspot is unknown. It will come into sharper focus later today and tomorrow as the region turns more directly toward Earth, revealing whether or not AR2109 has the kind of unstable magnetic field that leads to strong flares. For now, solar activty remains low despite the increasing sunspot count.   July 2, 2014 -For people in the northern hemisphere, July is the best time of the year to see noctilucent clouds (NLCs). The month got off to a good start on July 1st when the sunrise over Radebeul, Germany turned electric-blue. "This morning was extremely electric blue over Saxony," says photograher Heiko Ulbricht. "What a great display of noctilucent clouds! I spent much of the night watching the World Cup with friends. At about 2 o'clock in the morning, we drove to a field in Radebeul near the Astronomical Observatory. When the sun came up we were rewarded--a great morning! " NLCs are Earth's highest clouds. Seeded by "meteor smoke," they form at the edge of space 83 km above Earth's surface. When sunlight hits the tiny ice crystals that make up these clouds, they glow electric blue. NLCs appear during summer because that is when water molecules are wafted up from the lower atmosphere to mix with the meteor smoke. That is also, ironically, when the upper atmosphere is coldest, allowing the ice crystals of NLCs to form. The natural habitat of noctilucent clouds is the Arctic Circle. In recent years, however, they have spread to lower latitudes with sightings as far south as Utah and Colorado. This will likely happen in 2014 as well. Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.  July 1, 2014 -Big sunspot AR2104, which emerged over the weekend, has developed a 'beta-gamma-delta' magnetic field that harbors energy for X-class solar flares. So far, however, the sunspot has been relatively quiet, producing no more than a few minor C-flares. Sergio Castillo photographed the brooding giant on June 30th from his backyard observatory in Inglewood, CA. Castillo used a solar telescope capped with a "Calcium-K" filter tuned to 3933 Å, a wavelength that reveals the bright magnetic froth around active sunspots. "The magnetic froth is amazingly visible around AR2104," says Castillo. "I truly hope this active region brings fireworks just in time for the 4th of July." He might get his wish. NOAA forecasters estimate a growing 40% chance of M-class flares and a 5% chance of X-flares during the next 24 hours. The odds of geoeffective eruptions will increase even more in the days ahead as the sunspot turns toward Earth. -Ceres and Vesta at their closest. The two leading asteroids, currently magnitudes 8.4 and 7.1, are closing right in on each other as seen on the sky. They're not far above Mars and Spica after dark. They are within 1/3° of each other for the next week and will appear closest together, just 1/6° apart, on the evenings of July 4th and 5th.  June 30, 2014 -Now the thickening crescent Moon is higher and easier to see in twilight, with Jupiter farther to its lower right and stars of Leo above it, as shown here. -A pair of new sunspots is emerging over the sun's eastern limb--and they appear to be bigs ones. NASA's Solar Dynamics Observatory recorded their arrival during the early hours of June 29th. The sun has been mostly quiet for the past two weeks, and these sunspots could break the quiet. Already they are crackling with C-class solar flares. As the active regions turn toward Earth, we will be able to examine their magnetic fields and evaluate the posssibilitty that they harbor energy for stronger eruptions.    June 29, 2014 -Shortly after sunset, look for the thin waxing crescent Moon very low in the west-northwest, then look for Jupiter well to its right, as shown here. -Yesterday, NASA's "flying saucer"--a device designed to deliver heavy payloads to Mars--made its first test flight over Hawaii. "The vehicle worked beautifully, and we met all of our flight objectives," reports project manager Mark Adler of the Jet Propulsion Laboratory. Flight videos and a full report were issued at a news conference on June 29th. Videos can be found here: http://www.nasa.gov/jpl/ldsd/telecon2014/ Report: http://www.nasa.gov/jpl/ldsd/test-fl...sful-20140629/ June 28, 2014 -Can you see the big Coma Berenices star cluster from where you live? Does your light pollution really hide it, or do you just not know exactly where to look? It's 2/5 of the way from Denebola (Leo's tail) to the end of the Big Dipper's handle (Ursa Major's tail). Its brightest members form an inverted Y. The cluster is about 5° wide overall — a big, dim glow in at least a moderately dark sky. It nearly fills a binocular view. -During the early hours of June 27th, a series of bright CMEs billowed over the sun's northern limb. The Solar and Heliospheric Observatory (SOHO) recorded the blasts. NASA's STEREO probes saw the eruptions that gave birth to these clouds; the blast sites were on the farside of the sun. During STEREO's year-long brownout, pinpointing farside eruptions won't always be possible. Data trickling out of the STEREO's antenna's sidelobes simply cannot provide the kind of uninterrupted coverage required to catch every flare. The situation could worsen if, during STEREO's absence, something happens to SOHO. Launched in 1995, the Solar and Heliospheric Observatory is an old spacecraft operating far beyond its design lifetime. A mishap for SOHO could leave us without any operating space-based coronagraphs until STEREO comes back online in late 2015. Such a scenario would make it impossible to detect and track emerging CMEs. Imagine a whole year of space weather forecasting based on supposition and guesswork! This possibility highlights the need for a next generation of spacecraft to monitor the sun.  June 27, 2014 -This is the time of year when, at the end of dusk, the dim Little Dipper (Ursa Minor) floats straight upward from Polaris (the end of its handle) — like a helium balloon on a string, escaped from some summer evening party. Look due north. -Through light pollution, all you may see of the Little Dipper are Polaris at one end and Kochab, the lip of the Little Dipper's bowl, above it at the other. -NASA's twin STEREO probes, which can see the farside of the sun and make 3D models of incoming CMEs, have revolutionized space weather forecasting. We might have to do without them for a while. Later this year, the twin probes will pass directly behind the sun. Originally, mission planners expected a brief eclipse. Instead, operations could be curtailed for more than a year. The reason has to do with STEREO's high gain antenna feed. Ironically, when the antenna points too close to the sun, it overheats. As the probes pass behind the sun, they can't point their antennas at Earth without heat-sensitive components becoming dangerously hot. This engineering problem was not anticipated when STEREO was launched in 2006. On the bright side, it might be possible to avert a complete blackout using the antenna's sidelobes. Tests in July will evaluate this possibility. June 26, 2014 -If you have a really good dark sky, look east as the final glow of twilight fades away. All across the low eastern sky, the intricate, mottled band of the Milky Way is on the rise. It rises higher through the night and crosses straight overhead around 2 or 3 a.m. -The solstice sun has been very quiet. For more than five days there have been no significant flares, and the quiet appears set to continue. NOAA forecasters put the daily odds of an M- or X-class flare at no more than 1%. -With the arrival of summer, thunderstorm activity is underway across the USA. We all know what comes out of the bottom of thunderstorms: lightning. Lesser known is what comes out of the top: sprites. "Lately there has been a bumper crop of sprites," reports Thomas Ashcraft, a longtime observer of the phenomenon. "Here is one of the largest' 'jellyfish' sprites I have captured in the last four years." The cluster shot up from western Oklahoma on June 23, so large that it was visible from Ashcraft's observatory in New Mexico 289 miles away. "According to my measurements, it was 40 miles tall and 46 miles wide. This sprite would dwarf Mt. Everest!" he exclaims. Ashcraft's video: http://vimeo.com/99060196 Also in New Mexico, Jan Curtis saw a cluster of red sprites just one night later, June 24. "I've always wanted to capture these elusive atmospheric phenomena and last night I was finally successful." Although sprites have been seen for at least a century, most scientists did not believe they existed until after 1989 when sprites were photographed by cameras onboard the space shuttle. Now "sprite chasers" regularly photograph the upward bolts from their own homes. Ashcraft explains how he does it: "My method for photographing sprites is fairly simple. First I check for strong thunderstorms within 500 miles using regional radar maps accessible on the Internet. There must be a locally clear sky to image above the distant storm clouds. Then I aim my cameras out over the direction of the thunderstorms (which will be hot red or purple on the radar maps) and shoot continuous DSLR exposures. I usually shoot continuous 2 second exposures but if there is no moon then I will shoot up to 4 second exposures. Then I run through all the photographs and if I am lucky some sprites will be there. It might take hundreds to usually thousands of exposures so be prepared for many shutter clicks. I use a modified near infrared DLSR but any DLSR will capture sprites. Note that it does require persistence and a little bit of luck." Inhabiting the upper reaches of Earth's atmosphere alongside meteors, noctilucent clouds and some auroras, sprites are a true space weather phenomenon. Now is a good time to see them.  June 25, 2014 -With Scorpius now in fine evening view, keep an eye on the doings of Delta Scorpii. This is the middle star in the row of three marking Scorpius's head. In July 2000 it unexpectedly doubled in brightness. It has remained brighter than normal ever since, with fluctuations, at about magnitude 2.0. Compare it to Beta Scorpii above it, magnitude 2.6, and Antares, 1.1. -With only three small sunspot groups dotting the solar disk, and not one of them flaring, solar activity is low. NOAA forecasters estimate a scant 1% chance of M-flares on June 25th. -Looking at the sun can be a wincing, painful experience. Yesterday in Finland it was a rare delight. "On June 24th, multiple arcs and rings of light appeared around the sun," reports Ville Miettinen of Kuopio. "What a spectacular view!" He dashed inside and grabbed his camera to record the amazing vista." They lingered in the sky for three whole hours," he says, "only disappearing when thick clouds intervened." These luminous forms are called ice halos, because they caused by sunlight shining through icy crystals in cirrus clouds. Usually their forms are rather simple, like a solitary pillar or an uncomplicated ring. In this case, however, a complex assortment of halos criss-crossed the sky. In Miettinen's photo, we see a complete parhelic circle, a circumscribed halo, a supralateral arc, a 22-degree halo, and a pair of sundogs. Vesa Vauhkonen of Rautalampi, Finland, saw even more forms. "These were very, very impressive halos--some of them quite rare," he says. The variety of halos they witnessed was caused by a corresponding variety of ice crystals with rare gem-like perfection and unusually precise crystal-to-crystal alignment. What are the odds? No one knows but, apparently, they're higher in Finland.  June 24, 2014 -Mars and Spica shine in the southwest after dusk, with Arcturus high above them. Watch Mars move closer to Spica day by day. They'll pass each other on July 13th, just 1.3° apart. -Arriving about a day later than expected, a CME hit Earth's magnetic field on June 23rd at 2300 UT. The impact did not spark a geomagnetic storm. A second CME following close behind could, however, push the geomagnetic field over the threshold into storm conditions. A glancing blow is expected during the early hours of June 24th. -If you've never heard of a "damocloid", don't feel bad; even many professional astronomers don't know what they are. However, there are at least 50 of them moving through the Solar System. Named after protoptype object 5335 Damocles, a damocloid is an asteroid that follows a comet-like orbit. In fact, many damacloids turn out to be comets when, without warning, they suddenly sprout a tail. The latest to make this transformation is damacloid 2013 UQ4. Michael Jäger photographed it on June 23rd from his backyard observatory in Stixendorf, Austria. Discovered in the fall of 2013 by Catalina Sky Survey, 2013 UQ4 at first appeared to be a dark asteroid. On May 7, 2014, however, astronomers noticed a fuzzy atmosphere surrounding object's formerly-inert core. Barely two months later, it has sprouted a tail and is undeniably a comet. 2013 UQ4 swung by the sun in early June, a warm encounter that boosted the activity of its apparently icy nucleus. 2013 UQ4 is expected to brighten to binocular visibility (7th magnitude) by July 10th when it flies by Earth approximately 29 million miles (0.3 AU) away.  June 23, 2014 -Can you still see Jupiter in the sunset? Look low in the west-northwest about 45 minutes after sundown. If the air is clear it shouldn't be hard. Jupiter is heading away into conjunction with the Sun. -Moon and Venus at Dawn Tuesday. The waning crescent Moon forms a beautiful close pair with Venus in Tuesday's dawn, as seen from the Americas. Look low in the east, as shown at the top of this page. Look early enough, and you can see the Pleiades to their upper right. From other longitudes around the world, the Moon and Venus appear farther apart at the local time of dawn. -Regular sky watchers are accustomed to seeing rings of light around the sun. Called "ice halos," they form when sunlight shines through ice crystals in high clouds. Usually these rings appear one at a time. On June 21st, Jun Lao of Mason, Ohio, saw three at once. "It was about 4 p.m. EDT in the greater Cincinnati area when I imaged what I first thought was a regular halo, but was surprised to see three concentric halos!" says Lao. "The sky had a light cloud layer, and I suspect these multiple halos were caused by pyramidal ice crystals." Indeed, they were. Ordinary sun halos are produced by crystals shaped like pencils and flat plates. On rare occasions, however, the sky fills with pyramidal crystals. They look like two pyramids glued together, base-to-base. The pyramid-tips are sometimes truncated, and sometimes the two pyramids are separated by an intervening prism section, creating 18 different variations with up to 20 sides. Such a complicated crystalline form can produce multiple halos during the same display. These multiple halos are sometimes called "odd-radius halos." However, as atmospheric optics expert Les Cowley points out, "Odd radius halos are perhaps not so 'odd' or rare as usually thought. Make a point of routinely searching for them."  June 22, 2014 -What is the oldest thing you've ever seen? The Earth, Sun, Moon, and planets are 4.6 billion years old. The age record for people who occasionally glance at the sky might be Arcturus, about 7 billion years old. But with a pair of binoculars, you can pick up the 7.2-magnitude star HD 140283 in Libra, the constellation that houses Saturn these evenings. This star is in competition for the title of the oldest known, with an age recently measured at about 13 billion years. That means it formed just several hundred million years after the Big Bang. -NOAA forecasters estimate a 35% chance of minor geomagnetic storms today, June 22nd, when a CME is expected hit Earth's magnetic field. High-latitude sky watchers shoud be alert for auroras. -Assisted by the students of Earth to Sky Calculus, spaceweather.com has been launching a series of Space Weather Buoys to measure cosmic radiation in the stratosphere. A buoy consists of an insulated payload (a.k.a. K-Mart lunchbox) bristling with sensors and cameras, carried aloft by a suborbital helium balloon. On the latest flight, June 19th, the payload took a selfie. Below it is flying 95,000 feet above Earth's surface. The "SelfieCam" was designed by high school student Carson Reid. The goal of the ongoing experiment is to determine how radiation levels change during solar and geomagnetic storms, and how those changes affect the ozone layer. During each flight, the buoy gathers a complete radiation profile starting at the launch site in California's Eastern Sierras and extending up to 100,000+ feet. Such data are of interest to aviators, entrepreneurs in the emerging space tourism industry, and researchers of the ozone layer. Selfies are a visual bonus. A complete data set will be released in Oct. 2014 when the student scientists will have collected a full year of radiation measurements, spanning all four seasons and a variety of space weather conditions.  June 21, 2014 -If you have a good dark sky, look east as the final glow of twilight fades away. All across the low eastern sky on any clear night now, the starry, mottled band of the Milky Way is looming up. It rises higher through the night and crosses straight overhead around 3 a.m. -The June solstice occurs at 6:51 a.m. Eastern Daylight Time. This is when the Sun reaches its northernmost point in the sky for the year and begins its six-month return south. Summer begins in the Northern Hemisphere, where today is the longest day. In the Southern Hemisphere, this is the start of winter and the longest night.  June 20, 2014 -This is the time of year when the two brightest stars of summer, Arcturus and Vega, shine equally high overhead as evening grows late: Arcturus in the southwest, Vega toward the east. Arcturus and Vega are 37 and 25 light-years away, respectively. They represent the two commonest types of naked-eye stars: a yellow-orange K giant and a white A main-sequence star. They're 150 and 50 times more luminous than the Sun — which, combined with their nearness, is why they dominate the evening. -The season are changing. On June 21st, the sun will reach its northernmost point in the sky, +23.5 degrees above the celestial equator, marking the onset of summer in the north and winter in the south. Today is the last day of northern spring. Happy solstice! -A dark magnetic filament on the sun erupted during the late hours of June 19th. While one end of the filament remained connected to sunspot complex AR2093-AR2094, the other end corkscrewed wildly through the sun's atmosphere. Click the link to view the eruption, and keep an eye on the circled region in the preview below. http://www.spaceweather.com/images20...2_aia_0304.mp4 The corkscrewing filament hurled much of itself into space. Both of NASA's STEREO probes and the Solar and Heliospheric Observatory recorded a CME emerging from the blast site. A preliminary analysis suggests an expansion velocity near 600 km/s or 1.3 million mph. That may sound fast, but it is merely typical for a CME. The expanding cloud could deliver a glancing blow to Earth's magnetic field in a few days, possibly sparking a minor geomagnetic storm. June 19, 2014 -Around the northern hemisphere, sky watchers are starting to report a rainbow-colored sun halo that appears almost-exclusively during summer: the circumhorizon arc. "I saw one on June 13th. It was very bright," says Michail Anastasio, who snapped this picture from the cockpit of a plane flying 20,000 feet over Singapore. Nicknamed the "fire rainbow" because of its fiery rainbow colors, this apparition in fact has nothing to do with either fire or rainbows. It is caused by sunlight refracting through plate-shaped ice crystals in cirrus clouds. The geometry of the refraction requires that the sun be high in the sky (above 58o), which explains why this is a summertime phenomenon. June and July are the best months to see circumhorizon arcs. Look for them circling the horizon sometimes in patches, sometimes not, always brightly decorated with pure and well separated prismatic colors. You'll know it when you see it.  June 18, 2014 -With Scorpius coming up into good evening view now, keep an eye on the doings of Delta Scorpii. This is the middle star in the row of three marking Scorpius's head. In July 2000 it unexpectedly doubled in brightness. It has remained brighter than normal ever since, with fluctuations, at about magnitude 2.0. Compare it to Beta Scorpii above it, magnitude 2.6, and Antares, 1.1. -NASA Cassini spacecraft is swooping over Saturn's moon Titan today, June 18th, for a radar experiment to explore the nature of the moon's mysterious petroleum lakes. June 17, 2014 -Vega is the brightest star high in the east. Barely to its lower left after dark is one of the best-known multiple stars in the sky: 4th-magnitude Epsilon (ε) Lyrae, the Double-Double. It forms one corner of a roughly equilateral triangle with Vega and Zeta (ζ) Lyrae. The triangle is less than 2° on a side, hardly the width of your thumb at arm's length. Binoculars easily resolve Epsilon (not quite resolved in the photo here), and a 4-inch telescope at 100× or more should resolve each of Epsilon's two wide components into a tight pair. Zeta Lyrae, the triangle's third star, is also a double star for binoculars, much tougher, but it's easily split with a telescope. Delta Lyrae, the next star down, as a much wider binocular pair; it's resolved in the photo.  June 16, 2014 -After dark, look below Mars and Spica in the southwest for the four-star pattern of Corvus, the Crow. It's a springtime constellation descending now that spring is nearing its end. -NOAA forecasters estimate a 20% to 30% chance of minor geomagnetic storms on June 16-17 in response to a high-speed solar wind stream. Auroras may be difficult to see, however, because of glare from the waning full Moon. -With several active sunspots rotating over the sun's western limb, solar activity is quieting. The departure, however, is a riot. J. P. Brahic sends this picture of activity in the exit zone from Uzès, France. Brahic took the picture through cirrus clouds using a 9 inch solar telescope, and he inserted an image of Earth for scale. The dark cores of the departing sunspots are about the size of our planet, and the surrounding tangle of magnetic filaments could swallow Earth with room to spare. These sunspots are leaving behind at least one region still capable of major flares: AR2087 is almost directly facing Earth and it has a 'beta-gamma' magnetic field that harbors energy for M-class eruptions. Any flares from AR2087 today would hit Earth head on.  June 15, 2014 -The waning gibbous Moon rises in the east-southeast around 11 p.m. (depending on where you live). Well to its upper left shines Altair, flagged by the little star Tarazed about a finger-width at arm's length above it. Left or lower left of Altair, by about a fist and a half at arm's length, look for the compact constellation Delphinus, the Dolphin. -Red dwarfs are by far the most numerous type of star in the Galaxy, accounting for as much as 80% of the stellar population of the Milky Way. Because of this, astronomers looking for potentially habitable worlds have targeted red dwarf stars. A new study, however, shows that harsh space weather might strip the atmosphere of any rocky planet orbiting in a red dwarf's habitable zone, dooming life as we would know it in a majority of the Galaxy's planetary systems. story: http://smithsonianscience.org/2014/0...dwarf-planets/ -The northern summer solstice is just one week away. According to Jan Koeman of Philippus Lansbergen Observatory in Middelburg,the Netherlands, that means "it's time to check your solarcans." A solarcan, a.k.a. solargraph, is a pinhole camera made from a soda or beer can lined with a piece of photographic paper. Using such a simple device, it is possible to take extraordinarily long exposures of the daily sun--in this case, six months long. Yesterday, Koeman opened a solarcan he deployed in December, and this is what he found. Normally, solarcans record the graceful tracks the sun makes across the sky as the seasons unfold--high tracks corresponding to summer, low tracks to winter. In this case, the tracks were interrupted because Koeman deployed his solarcan inside a lighthouse. "I worried that the powerful light from the lighthouse would overwhelm the sun. Luckily our sun is much stronger. However, the fresnel prisms in the lighthouse were chopping up the sunlight."  June 14, 2014 -Mars and Spica arrest your eye in the southwest just after dark this week. Spot brighter Arcturus high above them. Half as far below them is the four-star pattern of Corvus, the Crow. -A CME expected to hit Earth's magnetic field on Friday the 13th did not show up. Either it missed or, as NOAA forecasters suspect, the storm cloud is still en route. A glancing blow on June 14th could spark a G1-class geomagnetic storm. -Two sunspots that have threatened Earth with flares during the past week will soon be gone. AR2080 and AR2085 are about to disappear over the sun's western limb. "These two amazing sunspot groups are saying goodbye with a splendid array of prominences, filaments and minor flare activity," reports Sergio Castillo who sends this parting shot from his backyard observatory in Corona, CA. Although these sunspots are leaving, they still pose a threat to Earth. Both of them are well-connected to our planet by the sun's spiraling magnetic field. If one of them erupts this weekend--a distinct possibility--energetic particles could be funneled by magnetic forces back toward Earth, causing a solar proton storm. Meanwhile, another active sunspot is not leaving: AR2087 is almost directly facing Earth and it has a 'beta-gamma-delta' magnetic field that harbors energy for X-class solar flares. Any eruption from this sunspot would hit Earth head on. NOAA forecasters estimate a 30% chance of X-flares on June 14th.  June 13, 2014 -Vega is the brightest star shining in the east after dusk. It's currently the top star of the big Summer Triangle. The brightest star to Vega's lower left is Deneb. Look farther to Vega's lower right for Altair. The Summer Triangle will climb higher in early evening all through the summer, to pose highest overhead at dusk when fall begins. -A coronal mass ejection hurled into space by the double X-flare of June 10th could sideswipe Earth's magnetic field today. NOAA forecasters estimate a 50% chance of polar geomagnetic storms in response to the glancing blow. -For soccer fans, Friday the 13th is a lucky day because the World Cup is underway. The world's biggest sports event began yesterday in Brazil with a game between the host country and Croatia. (Brazil won.) To celebrate the kickoff, Jean-Baptiste Feldmann took this picture of the Moon rising over Nuits-Saint-Georges, France. The fact that this month's full Moon falls on Friday the 13th has been widely noted in the media. Such a coincidence is not particularly rare. The last Friday the 13th full Moon occurred on Aug. 13, 2011. The next one will be on Aug. 13, 2049. Neither is the coincidence unlucky. Folklore holds that all kinds of wacky things happen under the light of a full Moon. Supposedly, hospital admissions increase, the crime rate ticks upward, and people behave strangely. The idea that the full Moon causes mental disorders was widespread in the Middle Ages. Even the word "lunacy," meaning "insanity," comes from the Latin word for "Moon." The majority of modern studies, however, show no correlation between the phase of the Moon and the incidence of crime, sickness, or human behavior. This is true even on Fridays. -Last week NASA's Curiosity rover witnessed something no one has ever seen from the surface of another world: a planetary transit of the sun. As the sun rose over Mars' Gale Crater on June 3rd, Curiosity's two-eyed MastCam tracked the shadowy silhouette of Mercury crossing the solar disk. In addition to showing Mercury, the same MastCam frames show two sunspots approximately the size of Earth. This is the first transit of the sun by a planet observed from any planet other than Earth, and also the first imaging of Mercury from Mars. Mercury fills only about one-sixth of one pixel as seen from such a great distance, so the darkening does not have a distinct shape. Nevertheless, it is definitely Mercury as the shadow follows Mercury's expected path based on orbital calculations. On Earth, it is possible to observe solar transits of Mercury and Venus, although they are rare. Last seen in June 2012, Venus transits are typically separated by more than a hundred years. The next Mercury transit visible from Earth will be May 9, 2016. Mercury and Venus transits are visible more often from Mars than from Earth, and Mars also offers a vantage point for seeing Earth transits. The next of each type visible from Mars will be Mercury in April 2015, Venus in August 2030 and Earth in November 2084.  June 12, 2014 [left]-Solar activity remains high. Active sunspot AR2087 unleashed another X-flare on June 11th (X1.0), following two X-flares (X2.1 and X1.5) on June 10th. The latest blast was intense but short-lived, and it is not expected to have significant Earth-effects. -Full Moon (exact at 12:11 a.m. June 13th EDT). The Moon shines in the dim legs of the constellation Ophiuchus. Look for Antares well to its right. June 11, 2014 -Now it's Antares's turn to shine near the Moon. As evening grows late, it swings straight below the Moon (for North America). -Yesterday's double X-flare may have produced a geoeffective CME after all. At first it appeared that Earth was outside the line of fire, but a closer look at the CME reveals an Earth-directed component. Click to view a movie of the explosion from the Solar and Heliospheric Observatory: The movie shows a faint CME associated with the first X-flare emerging around 1200 UT. A second, brighter CME from the second X-flare quickly overtakes it, forming a "cannibal CME." Computer models run yesterday by NOAA analysts suggest the merged storm cloud will reach Earth mid-day on June 13th. The glancing blow could spark polar geomagnetic storms. Meanwhile, more X-flares are in the offing. At least two sunspots (AR2080 and AR2087) have unstable 'delta-class' magnetic fields that could erupt at any moment. The source of yesterday's X-flares, AR2087, is particularly potent, and it is turning toward Earth. NOAA forecasters estimate a 60% chance of M-flares and a 30% chance of X-flares on June 11th.   June 10, 2014 -Last night, June 9th, a spectacular display of noctilucent clouds (NLCs) swept across central Europe. "I have waited three years to take a picture like this," says Piotr Majewski who witnessed the apparition at the Torun Centre for Astronomy in Poland. "Noctilucent cloud season has officially begun here in Poland," says Marek Nikodem. "I saw the same display from the town of Szubin, and it was spectacular." Nikodem is a long-time photographer of noctilucent clouds. Last night he framed a nest of storks backlit by electric blue. Noctilucent clouds are a summertime phenomenon. NASA's AIM spacecraft spotted the first NLCs of the 2014 season on May 24th, and they have been intensifying ever since. Long ago, NLCs were confined to the Arctic, but in recent years they have been sighted as far south as Colorado and Utah. Some researchers think the increasing visibility is a sign of climate change. Whatever the cause, sky watchers should be alert for NLCs as northern summer unfolds. Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud. -Now the waxing gibbous Moon is lower left of Saturn at nightfall. Look farther to the Moon's lower left for Antares and the other stars of upper Scorpius, as shown here. For southernmost Africa, the Moon occults (covers) Saturn around 19 hours Universal Time.  June 9, 2014 -The Moon is part of a four-object lineup tonight: with Saturn to its left and Spica and Mars to its right. -With summer not far off, can you still catch Procyon very low in the twilight? You may need binoculars. It's 17° lower left of Jupiter. For how many more days can you follow it? The first day that a star becomes completely invisible in the afterglow of sunset is called its heliacal setting. -Over the weekend, the sky above Canada and many northern-tier US states turned purple. It was the aurora borealis, sparked by a CME impact during the late hours of June 7th. "Wonderful purple and blue auroras spanned the sky, peaking between 2 and 2:30 a.m. MDT on June 8th," reports Alan Dyer, who captured the colors outside an old barn in Alberta, Canada. In auroras, purple is a sign of nitrogen. While oxygen atoms produce the green glow in Dyer's image, the purple comes from molecular nitrogen ions at very high altitudes. For some reason, high-altitude nitrogen was unusually excited during this G2-class geomagnetic storm, and many people witnessed its telltale hue. More purple could be in the offing. A solar wind stream following in the wake of the CME has kept Earth's magnetic field unsettled two full days after the CME's impact. Solar wind speeds are now greater than 500 km/s, prompting NOAA forecasters to boost the odds of a polar geomagnetic storm on June 9th to 50%.  June 8, 2014 -High-latitude sky watchers should be alert for auroras as Earth passes through the wake of a CME that struck on June 7th. The initial impact of the CME was weak, but as June 7th turned into June 8th a G2-class geomagnetic storm developed. At its peak, the storm sparked Northern Lights in the USA as far south as Wisconsin. "There was a quick burst of northern lights in New Auburn WI tonight," says photographer Justin Phillips. "For 10 minutes the pinks were just incredible. What a way to end the aurora drought!" -NOAA forecasters say CME effects could persist until June 9th with a 25% chance of continued geomagnetic storms.   June 7, 2014 -The waxing gibbous Moon shines near Mars this evening. Look just above Mars for fainter Gamma (γ) Virginis (Porrima). Spica shines farther to their their left. -NOAA forecasters have boosted the odds of an M-class flare on June 7th to 35%. To see why, pay close attention to the image below. During the past 48 hours, three large sunspot groups have materialized. Nearly invisible on June 5th, now the active regions are peppered with dark cores larger than Earth. All three regions have unstable magnetic fields that pose a threat for significant eruptions. The greatest threat comes from sunspot AR2080. Its 'beta-gamma-delta' magnetic field harbors energy not only for medium M-class flares, but also for powerful X-flares. Because AR2080 is centrally located on the solar disk, any flares this weekend will likely be Earth-directed.  June 6, 2014 -Look left of the Moon this evening for Mars, then Spica. With June under way, the Big Dipper is swinging around after dark to hang down by its handle high in the northwest. The middle star of its handle is Mizar, with tiny little Alcor right next to it. On which side of Mizar should you look for Alcor? As always, on the side toward Vega! Which is now shining in the east-northeast. -NASA's AIM spacecraft saw the first wispy noctilucent clouds (NLCs) of the 2014 summer season on May 24th. Since then NLCs have begun to intensify around the Arctic Circle and descend to lower latitudes. This morning, June 6th, Noel Blaney spotted a bank of the electric-blue clouds over Bangor, Northern Ireland. "I witnessed this nice early-season noctilucent cloud display over Belfast Lough at 2am," says Blaney. "These are my first proper images of NLCs!" A few hours later, Lance Taylor saw more NLCs over Edmonton, Alberta. "This was my first sighting of the season - and I have been watching for them for the past two weeks now," he says. Seeded by meteor smoke and boosted by the climate-change gas methane, noctilucent clouds have been spreading beyond the Arctic. In recent years, they have been sighted as far south as Colorado and Utah. Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.  June 5, 2014 -It is well known that ice crystals in high clouds can catch the light of the sun, bending its rays to produce beautiful circular halos in the sky. Last month, Alan Clark of Calgary, Alberta, saw such a halo, but it was strangely broken. "I saw this unusual halo on May 17th," says Clark. "It appears that a sharp transition between clouds of significantly different ice crystal types crossed in front of the Sun, [producing jagged edges around the circle]." To investigate this possibility, Clark simulated the display using the HaloSim program written by atmospheric optics experts Les Cowley and Michael Shroeder. The results are shown in the upper right, above. "I used different crystal types in the upper and lower parts of this halo," explains Clark. "In the simulation, one cloud consisted of 30% of horizontal hexagonal columnar crystals and 70% hexagonal flat-plate crystals with a wide dispersion of angles of their faces to the horizontal. The other cloud contained hexagonal columnar crystals with their axes distributed randomly." The computer-generated halo was a good match to what Clark saw. "I agree entirely with Alan's interpretation," notes Les Cowley. "It is a very unusual observation indeed. The upper halo is a fragment of a circumscribed halo generated by the horizontal column crystals. The lower halo is a fragment of the familiar 22-degree halo from randomly oriented crystals."  June 4, 2014 -As the stars come out, Regulus and the Sickle of Leo are now upper right of the Moon. -Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. On Jun. 3, 2014, the network reported 33 fireballs. (33 sporadics)   June 3, 2014 -Look above the Moon early this evening for Regulus and Gamma (γ) Leonis, slightly fainter. They're the two brightest stars of the Sickle of Leo. -On August 27, 2014, Comet C/2012 K1 PanSTARRS will buzz Earth's orbit only 0.05 AU away. Unfortunately for sky watchers, Earth won't be there. Our planet will be on the other side of the sun during PanSTARRS's close approach. A better time to photograph the comet is now. UK astronomer Damian Peach took this picture from his backyard observatory in Selsey, West Sussex, on May 31st. His picture highlights the comet's vivid green atmosphere or "coma". The verdant hue is a sign of diatomic carbon and cyanogen, two gases that grow green when illuminated by sunligght in the near-vacuum of space. "The comet's long ion tail is still rather faint," notes Peach. To pull it out of the starry background required a 30 minute exposure with his 4-inch telecope. PanSTARRS K1 is currently moving through Ursa Major, shining about as brightly as an 8th magnitude star. This makes it an easy target for mid-sized backyard telescopes, albeit invisible to the naked eye. Amateur astronomers who wish to image the comet can find orbital elements and an ephemeris here. If Earth and the comet were on the same side of the sun in August, the view would be spectacular. Disappointment will be mitigated, only a little, by images from the Solar and Heliospheric Observatory. SOHO's C3 coronagraph will track the comet as it passes behind the sun (from our point of view) from August 2nd until August 16th.  June 2, 2014 -With summer not far off, can you still catch Procyon low in the twilight? It's lower left of Jupiter and, this evening, below or perhaps lower right of the Moon (depending on your latitude). How much later into the season can you follow it? The first day that a star becomes completely invisible in the afterglow of sunset is called its heliacal setting. -On August 27, 2014, Comet C/2012 K1 PanSTARRS will buzz Earth's orbit only 0.05 AU away. Unfortunately for sky watchers, Earth won't be there. Our planet will be on the other side of the sun during PanSTARRS's close approach. A better time to photograph the comet is now. UK astronomer Damian Peach took this picture from his backyard observatory in Selsey, West Sussex, on May 31st. His picture highlights the comet's vivid green atmosphere or "coma". The verdant hue is a sign of diatomic carbon and cyanogen, two gases that grow green when illuminated by sunligght in the near-vacuum of space. "The comet's long ion tail is still rather faint," notes Peach. To pull it out of the starry background required a 30 minute exposure with his 4-inch telecope. PanSTARRS K1 is currently moving through Ursa Major, shining about as brightly as an 8th magnitude star. This makes it an easy target for mid-sized backyard telescopes, albeit invisible to the naked eye. Amateur astronomers who wish to image the comet can find orbital elements and an ephemeris here. If Earth and the comet were on the same side of the sun in August, the view would be spectacular. Disappointment will be mitigated, only a little, by images from the Solar and Heliospheric Observatory. SOHO's C3 coronagraph will track the comet as it passes behind the sun (from our point of view) from August 2nd until August 16th. June 1, 2014 -At nightfall, Mars shines yellow-orange in the south. Look 4° (two or three finger-widths at arm's length) above it for 3rd-magnitude Porrima (Gamma Virginis). This is a famous, fast-changing close double star for telescopes. This year its two components, equal in brightness, are 2.2 arcseconds apart. A decade ago they were unresolvable. -For the third night in a row, there's something extra in the sunset: Jupiter and the crescent Moon. Separated by less than 10o, the two bright bodies pop out of the twilight as soon as the sun goes down. Take a look! -With no sunspots actively flaring, the face of the sun is quiet. The edge of the sun is another matter. Amateur astronomers around the world are monitoring a bushy filament of plasma seething over the sun's southeastern limb. Sergio Castillo sends this picture from his backyard observatory in Inglewood, California. "This gigantic prominence spreading its plasma material and gases on the limb makes an excellent target for imaging," says Castillo. The hot gas in this prominence is held aloft by solar magnetic fields. If those fields become unstable the structure could collapse, causing an explosion when it hits the stellar surface below. This kind of explosion, which occurs without the aid of a sunspot, is called a "Hyder flare."   Older archived posts may be found here: March 10, 2012 - August 31, 2012 September 1, 2012 - February 28, 2013 March 1, 2013 - July 31, 2013 August 1, 2013 - December 31, 2013 January 1, 2014 - May 31, 2014 News: June 24, 2014 Shadow of a Supervoid  May 28, 2014 New, Intriguing Double Martian Crater  April 24, 2014 Jupiter’s Not-So-Great Red Spot  April 10, 2014 April’s Total Eclipse of the Moon  April 4, 2014 LADEE Skims the Moon Before Crash  March 29, 2014 Global "Fail" for the Big Regulus Cover-up  March 28, 2014 Rosetta Spots Its Comet  March 25, 2014 Have We Spotted Dark Matter in the Milky Way?  March 17, 2014 First Direct Evidence of Big Bang Inflation  March 13, 2014 Regulus Occultation: Asteroid to Black Out Bright Star  March 4, 2014 Zodiacal Light in the Evening  February 28, 2014 New Record for Oldest Earth Rock  February 21, 2014 Mapping a Supernova's Radioactive Glow  February 20, 2014 The Purest Star Tells an Ancient Tale  February 14, 2014 Unveiling Ganymede  January 31, 2014 Mystery of the Missing Galaxy Clusters  January 23, 2014 "Dwarf Planet" Ceres Exhales Water  January 22, 2014 Bright Supernova in M82  January 20, 2014 The End of Rosetta's Big Sleep  January 10, 2014 Galaxies Trace Early Cosmic History  January 4, 2014 Huge Sunspot Group Now Observable  January 2, 2014 Small Asteroid 2014 AA Hits Earth  December 30, 2013 Eclipses in 2014  December 30, 2013 Meteor Showers in 2014  December 19, 2013 Gaia Launches to Pinpoint a Billion Stars  December 17, 2013 See Venus's Thin Crescent  December 16, 2013 Argon Found in The Crab  December 14, 2013 Chang'e 3 Delivers Rover to Lunar Surface  December 11, 2013 Comet ISON: What We've Learned  December 10, 2013 A Double Black Hole?  December 9, 2013 New View of Saturn's Hexagon  November 7, 2013 New Chelyabinsk Results Yield Surprises  October 29, 2013 November 3rd's Rare Solar Eclipse  October 19, 2013 (Maybe) Watch a Binary Asteroid "Wink Out"  October 18, 2013 Undue Ado About Asteroid 2013 TV135  October 18, 2013 October 18th's Penumbral Lunar Eclipse  October 16, 2013 Huge Meteorite Pulled from Russian Lake  October 13, 2013 Warm Glow from an Orphaned Planet  October 4, 2013 Donations Needed for Eclipse-Glasses Effort  October 3, 2013 The Quest for Zodiacal Light October 1, 2013 News Posted Today: Uranus's Unlikely Companion  September 23, 2013 Is Phaethon a "Rock Comet"?  September 15, 2013 Hisaki: An Orbiting Planetary Observatory  September 11, 2013 Deep Impact on the Fritz  September 5, 2013 LADEE Leaves for Luna  September 2, 2013 An Annular Eclipse on Mars  September 1, 2013 Sun Loses Lithium with Age  August 27, 2013 Green Bank Telescope Secures $1 Million Boost  August 15, 2013 New Pulsar Explores Heart of Milky Way  August 14, 2013 Bright Nova in Delphinus  August 7, 2013 Under Stress, Asteroids May Be Fragile  August 6, 2013 Get Ready for the 2013 Perseids  August 5, 2013 Subaru Sees New Planet Directly  July 29, 2013 Supernova Erupts in M74  July 19, 2013 Wave at Saturn — But Will Cassini See You?  July 17, 2013 Magnifying Quasars  July 15, 2013 The Sun's Heat Wave  July 14, 2013 A Tale of the Sun's Tail  June 30, 2013 Now Playing: Core Collapse in 3D  June 29, 2013 Good-bye to GALEX  June 20, 2013 The Myth of the Supermoon  June 19, 2013 A Billion Pixels of Mars-scape  June 18, 2013 Winds on Venus: Getting Stronger  June 4, 2013 Radiation Risks for Future Marsonauts Source:  June 3, 2013 Chance to Catch Closest Planet? Source:  May 21, 2013 A Bright Flash in the (Lunar) Night  May 16, 2013 Kepler Goes Down - and Probably Out  May 10, 2013 A Cosmic Sleight of Hand  May 3, 2013 Lingering Echoes of Comet S-L 9's Demise  May 1, 2013 Saturn is Making Waves  April 29, 2013 One Gap, No Planets  April 29, 2013 Herschel Breathes Its Last  April 26, 2013 See Saturn at Its Best for 2013  April 19, 2013 A Tumbling Apophis: Good News for Earth  April 12, 2013 The Most Distant Star Ever Seen?  April 11, 2013 Has the Mars 3 Lander Been Found?  April 9, 2013 A New Type of Supernova  March 26, 2013 Closest Brown Dwarf System Discovered  March 23, 2013 Curiosity Wades Into Mudstone and More  March 21, 2013 Planck: Best Map Yet of Cosmic Creation  March 1, 2013: Mars has Front-Row Seat for 2014 Comet  February 21, 2013 Info on Russian Meteor Pours In February 19, 2013 Star HD 140283 is confirmed roughly as old as the universe  February 18, 2013 Baby Black Hole Discovered  February 15, 2012 Lessons from Today’s Russia Meteor Impact  February 1, 2013 The First-Ever Meteorite from Mercury?  January 30, 2013 Asteroid 2012 DA14 to Zip Past Earth  January 24, 2013 Pulsar Twitches Leave Astronomers Perplexed  January 18, 2013 Mapping the Milky Way  January 16, 2013 Galactic Bubbles Spark Debate  January 12, 2013 NGC 6872: Largest Spiral Galaxy Known  December 28, 2012 Triple Stars in Far-Flung Relationships  December 27, 2012 Radio Astronomy in the Aussie Outback  December 20, 2012 Planets Around Tau Ceti?  December 15, 2012 Toutatis Revealed by Chinese Spacecraft  December 12, 2012 Big River on Titan  December 7, 2012 Spacetime Ripples on the Horizon?  December 6, 2012 Gravity Probes Unlock Deep Lunar Secrets.  Aurora Tracker: Depending on your location, use the KP = n scale to find out if auroras are possible where you live. You must live above the magnetic line of a certain number in order to have a chance in seeing auroras.    North America:  Eurasia:  Meteor Tracker: The following information is taken from http://fireballs.ndc.nasa.gov/. By clicking this link, you can view recordings of bright fireballs [meteorites brighter than the planet Venus or magnitude -4] caught by cameras pointed in the sky 24/7 in the navigation panel on the left. Simply click the date of the day you are interested in viewing! Cameras are placed in the following orientation:  The following plots show the location of meteor shower radiants as detected in near real-time by the MEO-sponsored multi-station Canadian Meteor Orbit Radar (CMOR). Each day approximately 4000-5000 individual meteoroid orbits are measured by CMOR - the amount of "clumpiness" in these radiants determines the location of individual showers. Groupings of radiants in location and speed are localized using a 3D wavelet transform technique and the associated showers listed by their three letter International Astronomical Union code. The source of all IAU Codes can be found here. Skymap Activity This plot shows the apparent radiant activity overlaid on a map of the sky as seen from the radar station (43N, 81W) at the time indicated. The sun and moon are also displayed.  Meteorite Velocity This plot shows the same view as the skymap activity plot, but with individual radiants color coded by their speed.  Noctilucent Clouds Tracker:  International Space Station Tracker: Source: To find out when the International Space Station will pass over your head, go here to select your location and timezone, hit submit, and then click "10 day predictions for ISS". From there, you will see a table that gives you the date, brightness in magnitude, Start time, altitude, and azimuth, Highest point time, altitude and azimuth, and End Time, altitude and azimuth. The lower the number, the brighter the space station will be. Generally, the higher the altitude, the brighter it will be as well because there is less atmosphere for it to travel through. These are the best times to view the space station. It will only be around for a few minutes! If you've ever wondered how the Earth looks like from the ISS, take a look at this video. Thanks Reach for the find! Light Pollution Maps: World:  Europe:  United States, Lower Canada, Northern Mexico:  Request a light pollution map for your location, and I will get you one. This is what I have for now. I caution that pictures can get very large here. Scale: Black: Gegenschein visible. Zodiacal light annoyingly bright. Rising milkyway confuses some into thinking it's dawn. Limiting magnitude 7.6 to 8.0 for people with exceptional vision. Users of large dobsonian telescopes are very happy. Grey: Faint shadows cast by milkyway visible on white objects. Clouds are black holes in the sky. No light domes. The milky way has faint extentions making it 50 degrees thick. Limiting magntiude 7.1 to 7.5. Blue: Low light domes (10 to 15 degrees) on horizon. M33 easy with averted vision. M15 is naked eye. Milky way shows bulge into Ophiuchus. Limiting magnitude 6.6 to 7.0. Green: Zodiacal light seen on best nights. Milkyway shows much dark lane structure with beginnings of faint bulge into Ophiuchus. M33 difficult even when above 50 degrees. Limiting magnitude about 6.2 to 6.5. Yellow: Some dark lanes in milkyway but no bulge into Ophiuchus. Washed out milkyway visible near horizon. Zodiacal light very rare. Light domes up to 45 degrees. Limiting magnitude about 5.9 to 6.2. Orange: Milkyway washed out at zenith and invisible at horizon. Many light domes. Clouds are brighter than sky. M31 easily visible. Limiting magnitude about 5.6 to 5.9. Red: Milkyway at best very faint at zenith. M31 difficult and indestinct. Sky is grey up to 35 degrees. Limiting magntidue 5.0 to 5.5. White: Entire sky is grayish or brighter. Familliar constellations are missing stars. Fainter constellations are absent. Less than 20 stars visible over 30 degrees elevation in brigher areas. Limiting magntude from 3 to 4. Most people don't look up. CCD imaging is still possible. But telescopic visual observation is usually limited to the moon, planets, double stars and variable stars. Messier Objects and Sky Map:  Click the image to see the labelled version. The 3 letter labels are constellations found in a certain region of the sky, and the numbered labels are messier objects. The legend at the bottom left of this image tells you what each object is. The milky way band is shown throughout the image. Zoom in on the hyperlinked picture to read the labels more clearly. Astro Picture of the Day: October 28, 2014   Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun. During the most recent such pass starting late last year, Mars as usual, loomed large and bright. Also during this time, Mars appeared to move backwards in the sky, a phenomenon called retrograde motion. Featured here is a series of images digitally stacked so that all of the stars coincide. Here, Mars appears to trace out a narrow loop in the sky. At the center of the loop, Earth passed Mars and the retrograde motion was the highest. Retrograde motion can also be seen for other Solar System planets. Previous Days: October 27, 2014  What's that in front of the Sun? The closest object is an airplane, visible just below the Sun's center and caught purely by chance. Next out are numerous clouds in Earth's atmosphere, creating a series of darkened horizontal streaks. Farther out is Earth's Moon, seen as the large dark circular bite on the upper right. Just above the airplane and just below the Sun's surface are sunspots. The main sunspot group captured here, AR 2192, is one of the largest ever recorded and has been crackling and bursting with flares since it came around the edge of the Sun early last week. Taken last Thursday, this show of solar silhouettes was unfortunately short-lived. Within a few seconds the plane flew away. Within a few minutes the clouds drifted off. Within a few hours the partial solar eclipse of the Sun by the Moon was over. Only the sunspot group remains, but within a few more days even AR 2192 will disappear around the edge of the Sun. Fortunately, when it comes to the Sun, even unexpected alignments are surprisingly frequent. October 26, 2014  What would you see if you went right up to a black hole? Featured is a computer generated image highlighting how strange things would look. The black hole has such strong gravity that light is noticeably bent towards it - causing some very unusual visual distortions. Every star in the normal frame has at least two bright images - one on each side of the black hole. Near the black hole, you can see the whole sky - light from every direction is bent around and comes back to you. The original background map was taken from the 2MASS infrared sky survey, with stars from the Henry Draper catalog superposed. Black holes are thought to be the densest state of matter, and there is indirect evidence for their presence in stellar binary systems and the centers of globular clusters, galaxies, and quasars. October 25, 2014  A New Moon joined giant sunspot group AR 2192 to dim the bright solar disk during Thursday's much anticipated partial solar eclipse. Visible from much of North America, the Moon's broad silhouette is captured in this extreme telephoto snapshot near eclipse maximum from Santa Cruz, California. About the size of Jupiter, the remarkable AR 2192 itself darkens a noticeable fraction of the Sun, near center and below the curved lunar limb. As the sunspot group slowly rotates across the Sun and out of view in the coming days its activity is difficult to forecast. But the timing of solar eclipses is easier to predict. The next will be a total solar eclipse on March 20, 2015. October 24, 2014  As you (safely!) watched the progress of yesterday's partial solar eclipse, you probably also spotted a giant sunspot group. Captured in this sharp telescopic image from October 22nd the complex AR 2192 is beautiful to see, a sprawling solar active region comparable in size to the diameter of Jupiter. Like other smaller sunspot groups, AR 2192 is now crossing the Earth-facing side of the Sun and appears dark in visible light because it is cooler than the surrounding surface. Still, the energy stored in the region's twisted magnetic fields is enormous and has already generated powerful explosions, including two X-class solar flares this week. Coronal mass ejections (CMEs) associated with the flares have not affected planet Earth, so far. The forecast for further activity from AR 2192 is still significant though, as it swings across the center of the solar disk and Earth-directed CMEs become possible. October 23, 2014  This wide, sharp telescopic view reveals galaxies scattered beyond the stars and faint dust nebulae of the Milky Way at the northern boundary of the high-flying constellation Pegasus. Prominent at the upper right is NGC 7331. A mere 50 million light-years away, the large spiral is one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. The disturbed looking group of galaxies at the lower left is well-known as Stephan's Quintet. About 300 million light-years distant, the quintet dramatically illustrates a multiple galaxy collision, its powerful, ongoing interactions posed for a brief cosmic snapshot. On the sky, the quintet and NGC 7331 are separated by about half a degree. October 22, 2014 One of the largest sunspot groups in recent years is now crossing the Sun. Labelled Active Region 2192, it has already thrown a powerful solar flare and has the potential to produce more. The featured video shows a time lapse sequence of the Sun in visible and ultraviolet light taken yesterday and incorporating the previous 48 hours. AR 2192, rotating in from the left, rivals Jupiter in size and is literally crackling with magnetic energy. The active Sun has caused some spectacular auroras in recent days, and energetic particles originating from AR 2192 may help continue them over the next week. Tomorrow, the Sun will appear unusual for even another reason: a partial solar eclipse will be visible before sunset from much of North America. October 21, 2014  Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn's smallest moons. The crater, named Herschel after the 1789 discoverer of Mimas, Sir William Herschel, spans about 130 kilometers and is pictured above. Mimas' low mass produces a surface gravity just strong enough to create a spherical body but weak enough to allow such relatively large surface features. Mimas is made of mostly water ice with a smattering of rock - so it is accurately described as a big dirty snowball. The above image was taken during the 2010 February flyby of the robot spacecraft Cassini now in orbit around Saturn. A recent analysis of Mimas's unusual wobble indicates that it might house a liquid water interior ocean. October 20, 2014  Yesterday, a comet passed very close to Mars. In fact, Comet C/2013 A1 (Siding Spring) passed closer to the red planet than any comet has ever passed to Earth in recorded history. To take advantage of this unique opportunity to study the close interaction of a comet and a planet, humanity currently has five active spacecraft orbiting Mars: NASA's MAVEN, MRO, Mars Odyssey, as well as ESA's Mars Express, and India's Mars Orbiter. Most of these spacecraft have now sent back information that they have not been damaged by small pieces of the passing comet. These spacecraft, as well as the two active rovers on the Martian surface -- NASA's Opportunity and Curiosity -- have taken data and images that will be downloaded to Earth for weeks to come and likely studied for years to come. The featured image taken yesterday, however, was not taken from Mars but from Earth and shows Comet Siding Spring on the lower left as it passed Mars, on the upper right. October 19, 2014  Comet McNaught was perhaps the most photogenic comet of modern times -- from Earth. After making quite a show in the northern hemisphere in early January of 2007, the comet moved south and developed a long and unusual dust tail that dazzled southern hemisphere observers. In late January 2007, Comet McNaught was captured between Mount Remarkable and Cecil Peak in this spectacular image taken from Queenstown, South Island, New Zealand. The bright comet dominates the right part of the above image, while the central band of our Milky Way Galaxy dominates the left. Careful inspection of the image will reveal a meteor streak just to the left of the comet. Today, Comet Siding Spring may become the most photogenic comet of modern times -- from Mars. October 18, 2014  Cosmic clouds form fantastic shapes in the central regions of emission nebula IC 1805. The clouds are sculpted by stellar winds and radiation from massive hot stars in the nebula's newborn star cluster, Melotte 15. About 1.5 million years young, the cluster stars are toward the right in this colorful skyscape, along with dark dust clouds in silhouette against glowing atomic gas. A composite of narrowband and broadband telescopic images, the view spans about 30 light-years and includes emission from ionized hydrogen, sulfur, and oxygen atoms mapped to green, red, and blue hues in the popular Hubble Palette. Wider field images reveal that IC 1805's simpler, overall outline suggests its popular name - The Heart Nebula. IC 1805 is located about 7,500 light years away toward the boastful constellation Cassiopeia. October 17, 2014  This looks like a near miss but the greenish coma and tail of Comet Siding Spring (C/2013 A1) are really 2,000 light-years or so away from the stars of open cluster Messier 6. They do appear close together though, along the same line-of-sight in this gorgeous October 9th skyscape toward the constellation Scorpius. Still, on Sunday, October 19th this comet really will be involved in a near miss, passing within only 139,500 kilometers of planet Mars. That's about 10 times closer than any known comet flyby of planet Earth, and nearly one third the Earth-Moon distance. While an impact with the nucleus is not a threat the comet's dust, moving with a speed of about 56 kilometers per second relative to the Red Planet, and outskirts of its gaseous coma could interact with the thin Martian atmosphere. Of course, the comet's close encounter will be followed intently by spacecraft in Martian orbit and rovers on the surface. October 16, 2014  This Rosetta spacecraft selfie was snapped on October 7th. At the time the spacecraft was about 472 million kilometers from planet Earth, but only 16 kilometers from the surface of comet 67P/Churyumov-Gerasimenko. Looming beyond the spacecraft near the top of the frame, dust and gas stream away from the comet's curious double-lobed nucleus and bright sunlight glints off one of Rosetta's 14 meter long solar arrays. In fact, two exposures, one short and one long, were combined to record the dramatic high contrast scene using the CIVA camera system on Rosetta's still-attached Philae lander. Its chosen primary landing site is visible on the smaller lobe of the nucleus. This is the last image anticipated from Philae's cameras before the lander separates from Rosetta on November 12. Shortly after separation Philae will take another image looking back toward the orbiter, and begin its descent to the nucleus of the comet. October 15, 2014  What is that changing object in a cold hydrocarbon sea of Titan? Radar images from the robotic Cassini spacecraft orbiting Saturn have been recording the surface of the cloud-engulfed moon Titan for years. When imaging the flat -- and hence radar dark -- surface of the methane and ethane lake called Ligeia Mare, an object appeared in 2013 just was not there in 2007. Subsequent observations in 2014 found the object remained -- but had changed! The featured image shows how the 20-km long object has appeared and evolved. Current origin speculative explanations include bubbling foam and floating solids, but no one is sure. Future observations may either resolve the enigma or open up more speculation. October 14, 2014  Higher than the highest mountain lies the realm of the aurora. Auroras rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from energetic electrons and protons striking atoms and molecules in the Earth's atmosphere. Somewhat uncommon, an auroral corona appears as a center point for a surrounding display and may occur when an aurora develops directly overhead, or when auroral rays are pointed nearly toward the observer. This picturesque but brief green and purple aurora exhibition occurred last month high above Kvaløya, Tromsø, Norway. The Sessøyfjorden fjord runs through the foreground, while numerous stars are visible far in the distance. October 13, 2014 What causes sprite lightning? Mysterious bursts of light in the sky that momentarily resemble gigantic jellyfish have been recorded for over 25 years, but their root cause remains unknown. Some thunderstorms have them -- most don't. Recently, however, high speed videos are better detailing how sprites actually develop. The featured video is fast enough -- at about 10,000 frames per second -- to time-resolve several sprite "bombs" dropping and developing into the multi-pronged streamers that appear on still images. Unfortunately, the visual clues provided by these videos do not fully resolve the sprite origins mystery. They do indicate to some researchers, though, that sprites are more likely to occur when plasma irregularities exist in the upper atmosphere. Plasma Irregularities: http://www.nature.com/ncomms/2014/14...comms4740.html October 12, 2014  How did a star create the Helix nebula? The shapes of planetary nebula like the Helix are important because they likely hold clues to how stars like the Sun end their lives. Observations by the orbiting Hubble Space Telescope and the 4-meter Blanco Telescope in Chile, however, have shown the Helix is not really a simple helix. Rather, it incorporates two nearly perpendicular disks as well as arcs, shocks, and even features not well understood. Even so, many strikingly geometric symmetries remain. How a single Sun-like star created such beautiful yet geometric complexity is a topic of research. The Helix Nebula is the nearest planetary nebula to Earth, lies only about 700 light years away toward the constellation of Aquarius, and spans about 3 light-years. October 11, 2014  As the Moon rose and the Sun set on October 8, a lunar eclipse was in progress seen from Chongqing, China. Trailing through this composite time exposure, the rising Moon began as a dark reddened disk in total eclipse near the eastern horizon. Steadily climbing above the populous city's colorful lights along the Yangtze River, the moontrail grows brighter and broader, until a bright Full Moon emerged from the Earth's shadow in evening skies. Although lunar eclipses are not always total ones, this eclipse, along with last April's lunar eclipse, were the first two of four consecutive total lunar eclipses, a series known as a tetrad. The final two eclipses of this tetrad will occur in early April and late September 2015. October 10, 2014   From the early hours of October 8, over the Santa Cruz Mountains near Los Gatos, California, the totally eclipsed Moon shows a range of color across this well-exposed telescopic view of the lunar eclipse. Of course, a lunar eclipse can only occur when the Moon is opposite the Sun in Earth's sky and gliding through the planet's shadow. But also near opposition during this eclipse, and remarkably only half a degree or so from the lunar limb, distant Uranus is faint but easy to spot at the lower right. Fainter still are the ice giant's moons. While even the darkened surface of our eclipsed Moon will be strongly overexposed, Uranus moons Titania, Oberon, and Umbriel can just be distinguished as faint pinpricks of light. October 9, 2014  The Pacific Ocean and Chilean coast lie below this sea of clouds. Seen through the subtle colors of the predawn sky a lunar eclipse is in progress above, the partially eclipsed Moon growing dark. The curved edge of planet Earth's shadow still cuts across the middle of the lunar disk as the Moon sinks lower toward the western horizon. In fact, from this southern hemisphere location as well as much of eastern North America totality, the Moon completely immersed within Earth's shadow, began near the time of moonset and sunrise on October 8. From farther west the total phase could be followed for almost an hour though, the darker reddened Moon still high in the night sky. October 8, 2014  Star cluster NGC 6823 is slowly turning gas clouds into stars. The center of the open cluster, visible on the upper right, formed only about two million years ago and is dominated in brightness by a host of bright young blue stars. Some outer parts of the cluster, visible in the featured image's center as the stars and pillars of emission nebula NGC 6820, contain even younger stars. The huge pillars of gas and dust likely get their elongated shape by erosion from hot radiation emitted from the brightest cluster stars. Striking dark globules of gas and dust are also visible across the upper left of the featured image. Open star cluster NGC 6823 spans about 50 light years and lies about 6000 light years away toward the constellation of the Fox (Vulpecula). October 7, 2014   What connects the Sun to the Moon? Many answers have been given throughout history, but in the case of today's featured image, it appears to be the plane of our Milky Way Galaxy. The 16-image panorama was taken in Capitol Reef National Park, Utah, USA where two sandstone monoliths -- the Temple of the Moon on the left and the Temple of the Sun on the right -- rise dramatically from the desert. Each natural monument stands about 100 meters tall and survives from the Jurassic period 160 million years ago. Even older are many of the stars and nebula that dot the celestial background, including the Andromeda Galaxy. Tomorrow the Earth will connect the Sun to the Moon by way of its shadow: a total lunar eclipse will be visible from many locations around the globe. October 6, 2014  Where did all these high energy positrons come from? The Alpha Magnetic Spectrometer (AMS-02) onboard the International Space Station (ISS) has been meticulously recording how often it is struck by both high energy electrons and positrons since 2011. After accumulating years of data, it has now become clear that there are significantly more positrons than electrons at the highest energies detected. The excess may have a very exciting and profound origin -- the annihilation of distant but previously undetected dark matter particles. However, it is also possible that astronomical sources such as pulsars are creating the unexplained discrepancy. The topic remains a very active area of research. Pictured here, the AMS is visible on the ISS just after being installed, with a US Space Shuttle docked on the far right, a Russian Soyuz capsule docked on the far left, and the blue Earth that houses all nations visible across the background. October 5, 2014 Source: If the full Moon suddenly faded, what would you see? The answer during the total lunar eclipse of 2011 June was recorded in a dramatic time lapse video from Tajikistan. During a total lunar eclipse, the Earth moves between the Moon and the Sun, causing the moon to fade dramatically. The Moon never gets completely dark, though, since the Earth's atmosphere refracts some light. As the above video begins, the scene may appear to be daytime and sunlit, but actually it is a nighttime and lit by the glow of the full Moon. As the moon becomes eclipsed and fades, the wind dies down and background stars can be seen reflected in foreground lake. Most spectacularly, the sky surrounding the eclipsed moon suddenly appears to be full of stars and highlighted by the busy plane of our Milky Way Galaxy. The sequence repeats with a closer view, and the final image shows the placement of the eclipsed Moon near the Eagle, Swan, Trifid, and Lagoon nebulas. Nearly two hours after the eclipse started, the moon emerged from the Earth's shadow and its bright full glare again dominated the sky. The next total lunar eclipse will occur this Wednesday. October 4, 2014  Mars, Antares, Moon, and Saturn are the brightest celestial beacons in this serene sky. The Sun's golden light is still scattered along the southwestern horizon though, captured after sunset on September 28. The evening gathering of wandering planets and Moon along with the bright star viewed as an equal to Mars and the Scorpion's Heart was enjoyed around planet Earth. But from the photographer's perspective looking across the calm waters of Lake Balaton, Hungary, they were joined by a more terrestrial sailboat mast light. Mast light, bright star, planets and Moon are all posing near the plane of the ecliptic. October 3, 2014  Stepping stones seem to lead to the Milky Way as it stretches across this little sky. Of course, the scene is really the northern hemisphere's autumnal equinox night. Water and sky are inverted by a top to bottom, around the horizon stereographic projection centered on the zenith above Lake Storsjön in Jämtland, Sweden. In the north the Milky Way arcs from east to west overhead as fall begins, but the season is also a good time for viewing aurora. Geomagnetic storms increase in frequency near the equinox and produce remarkable displays of northern lights at high latitudes, like the eerie greenish glow reflected in this watery cosmos.e green channel. October 2, 2014  Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Below and left of the Bubble's center is a hot, O star, several hundred thousand times more luminous and around 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The intriguing Bubble Nebula and associated cloud complex lie a mere 11,000 light-years away toward the boastful constellation Cassiopeia. This tantalizing view of the cosmic bubble is composed from narrowband image data, recording emission from the region's ionized hydrogen and oxygen atoms. To create the three color image, hydrogen and oxygen emission were used for red and blue and combined to create the green channel. October 1, 2014  The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects. Though its wingspan covers over 3 light-years, NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the dying central star of this particular planetary nebula has become exceptionally hot, shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. This sharp close-up of the dying star's nebula was recorded in 2009 by the Hubble Space Telescope's Wide Field Camera 3, and is presented here in reprocessed colors. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius). September 30, 2014  Have you ever seen an entire rainbow? From the ground, typically, only the top portion of a rainbow is visible because directions toward the ground have fewer raindrops. From the air, though, the entire 360 degree circle of a rainbow is more commonly visible. Pictured here, a full circle rainbow was captured over Cottesloe Beach near Perth, Australia last year by a helicopter flying between a setting sun and a downpour. An observer-dependent phenomenon primarily caused by the internal reflection of sunlight by raindrops, the 84-degree diameter rainbow followed the helicopter, intact, for about 5 kilometers. As a bonus, a second rainbow that was more faint and color-reversed was visible outside the first. September 29, 2014  How did these Martian rocks form? As the robotic Curiosity rover has approached Pahrump Hills on Mars, it has seen an interesting and textured landscape dotted by some unusual rocks. The featured image shows a curiously round rock spanning about two centimeters across. Seemingly a larger version of numerous spherules dubbed blueberries found by the Opportunity rover on Mars in 2004, what caused this roundness remains unknown. Possibilities include frequent tumbling in flowing water, sprayed molten rock in a volcanic eruption, or a concretion mechanism. The inset image, taken a few days later, shows another small but unusually shaped rock structure. As Curiosity rolls around and up Mount Sharp, different layers of the landscape will be imaged and studied to better understand the ancient history of the region and to investigate whether Mars could once have harbored life. September 28, 2014  What's happening at the center of active galaxy 3C 75? The two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away. Astronomers conclude that these two supermassive black holes are bound together by gravity in a binary system in part because the jets' consistent swept back appearance is most likely due to their common motion as they speed through the hot cluster gas at 1200 kilometers per second. Such spectacular cosmic mergers are thought to be common in crowded galaxy cluster environments in the distant universe. In their final stages the mergers are expected to be intense sources of gravitational waves. September 27, 2014  Taken from an Atlantic beach, Cape Canaveral, planet Earth, four identically framed digital images are combined in this night skyscape. Slightly shifted short star trails dot the sky, but the exposure times were adjusted to follow the flight of a Falcon 9 rocket. The September 21 launch delivered a Dragon X capsule filled with supplies to the International Space Station. Above the bright flare seen just after launch, the rocket's first stage firing trails upward from the left. After separation, the second stage burn begins near center with the vehicle climbing toward low Earth orbit. At the horizon, the flare near center records the re-ignition and controlled descent of the Falcon 9's first stage to a soft splashdown off the coast. September 26, 2014  Launched on November 18, 2013, the MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft completed its interplanetary voyage September 21, captured into a wide, elliptical orbit around Mars. MAVEN's imaging ultraviolet spectrograph has already begun its planned exploration of the Red Planet's upper atmosphere, acquiring this image data from an altitude of 36,500 kilometers. In false color, the three ultraviolet wavelength bands show light reflected from atomic hydrogen (in blue), atomic oxygen (in green) and the planet's surface (in red). Low mass atomic hydrogen is seen to extend thousands of kilometers into space, with the cloud of more massive oxygen atoms held closer by Mars' gravity. Both are by products of the breakdown of water and carbon dioxide in Mars' atmosphere and the MAVEN data can be used to determine the rate of water loss over time. In fact, MAVEN is the first mission dedicated to exploring Mars' tenuous upper atmosphere, ionosphere and interactions with the Sun and solar wind. But the most recent addition to the fleet of spacecraft from planet Earth now in martian orbit is MOM. September 25, 2014  The large stellar association cataloged as NGC 206 is nestled within the dusty arms of the neighboring Andromeda galaxy. Also known as M31, the spiral galaxy is a mere 2.5 million light-years away. NGC 206 is near top center in this gorgeous close-up of the southwestern extent of Andromeda's disk, a remarkable composite of data from space and ground-based observatories. The bright, blue stars of NGC 206 indicate its youth. In fact, its youngest massive stars are less than 10 million years old. Much larger than the open or galactic clusters of young stars in the disk of our Milky Way galaxy, NGC 206 spans about 4,000 light-years. That's comparable in size to the giant stellar nurseries NGC 604 in nearby spiral M33 and the Tarantula Nebula, in the Large Magellanic Cloud. Star forming sites within Andromeda are revealed by the telltale reddish emission from clouds of ionized hydrogen gas. September 24, 2014  The large majestic Lagoon Nebula is home for many young stars and hot gas. Spanning 100 light years across while lying only about 5000 light years distant, the Lagoon Nebula is so big and bright that it can be seen without a telescope toward the constellation of Sagittarius. Many bright stars are visible from NGC 6530, an open cluster that formed in the nebula only several million years ago. The greater nebula, also known as M8 and NGC 6523, is named "Lagoon" for the band of dust seen to the left of the open cluster's center. A bright knot of gas and dust in the nebula's center is known as the Hourglass Nebula. The featured picture is a newly processed panorama of M8, capturing five times the diameter of the Moon. Star formation continues in the Lagoon Nebula as witnessed by the many globules that exist there. September 23, 2014   That's no sunset. And that thin red line just above it -- that's not a sun pillar. The red glow on the horizon originates from a volcanic eruption, and the red line is the eruption's reflection from fluttering atmospheric ice crystals. This unusual volcanic light pillar was captured over Iceland earlier this month. The featured scene looks north from Jökulsárlón toward the erupting volcano Bárðarbunga in the Holuhraun lava field. Even the foreground sky is picturesque, with textured grey clouds in the lower atmosphere, shimmering green aurora in the upper atmosphere, and bright stars far in the distance. Although the last eruption from Holuhraun was in 1797, the present volcanic activity continues. September 22, 2014 Earth is at equinox. Over the next 24 hours, day and night have nearly equal duration all over planet Earth. Technically, equinox transpires at 2:29 am Universal Time tomorrow, but this occurs today in North and South America. This September equinox signal that winter is approaching in the northern hemisphere, and summer is approaching in the south. At equinox, the dividing line between the sunlit half of Earth and the nighttime half of Earth temporarily passes through Earth's north and south spin poles. This dividing line is shown in clear detail in the featured video, taken by the Russian meteorological satellite Elektro-L during last year's September equinox. The Elektro-L satellite is in geostationary orbit over one spot on Earth's equator and always points directly toward the Earth. The featured video shows a time lapse for an entire day surrounding the equinox, with a new image taken every 30 minutes. Cloud motions are visible as well as the reflection of the Sun are visible as the equinox day progressed. The next Earth equinox is scheduled for March. September 21, 2014  How would Saturn look if its ring plane pointed right at the Sun? Before August 2009, nobody knew. Every 15 years, as seen from Earth, Saturn's rings point toward the Earth and appear to disappear. The disappearing rings are no longer a mystery -- Saturn's rings are known to be so thin and the Earth is so near the Sun that when the rings point toward the Sun, they also point nearly edge-on at the Earth. Fortunately, in this third millennium, humanity is advanced enough to have a spacecraft that can see the rings during equinox from the side. In August 2009, that Saturn-orbiting spacecraft, Cassini, was able to snap a series of unprecedented pictures of Saturn's rings during equinox. A digital composite of 75 such images is shown above. The rings appear unusually dark, and a very thin ring shadow line can be made out on Saturn's cloud-tops. Objects sticking out of the ring plane are brightly illuminated and cast long shadows. Inspection of these images is helping humanity to understand the specific sizes of Saturn's ring particles and the general dynamics of orbital motion. This week, Earth undergoes an equinox. September 20, 2014  Against dark rifts of interstellar dust, the ebb and flow of starlight along the Milky Way looks like waves breaking on a cosmic shore in this night skyscape. Taken with a digital camera from the dunes of Hatteras Island, North Carolina, planet Earth, the monochrome image is reminiscent of the time when sensitive black and white film was a popular choice for dimmly lit night- and astro-photography. Looking south, the bright stars of Sagittarius and Scorpius are near the center of the frame. Wandering Mars, Saturn, and Zubenelgenubi (Alpha Librae) form the compact triangle of bright celestial beacons farther right of the galaxy's central bulge. Of course, the evocative black and white beach scene could also be from that vintage 1950s scifi movie you never saw, "It Came From Beyond the Dunes." September 19, 2014  For astrobiologists, these may be the four most tantalizing moons in our Solar System. Shown at the same scale, their exploration by interplanetary spacecraft has launched the idea that moons, not just planets, could have environments supporting life. The Galileo mission to Jupiter discovered Europa's global subsurface ocean of liquid water and indications of Ganymede's interior seas. At Saturn, the Cassini probe detected erupting fountains of water ice from Enceladus indicating warmer subsurface water on even that small moon, while finding surface lakes of frigid but still liquid hydrocarbons beneath the dense atmosphere of large moon Titan. Now looking beyond the Solar System, new research suggests that sizable exomoons, could actually outnumber exoplanets in stellar habitable zones. That would make moons the most common type of habitable world in the Universe. September 18, 2014  In this crowded starfield covering over 2 degrees within the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. A compact star forming region, the cosmic Cocoon punctuates a long trail of obscuring interstellar dust clouds. Cataloged as IC 5146, the nebula is nearly 15 light-years wide, located some 4,000 light years away. Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by the young, hot stars and blue, dust-reflected starlight at the edge of an otherwise invisible molecular cloud. In fact, the bright star near the center of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it clears out a cavity in the molecular cloud's star forming dust and gas. But the long dusty filaments that appear dark in this visible light image are themselves hiding stars in the process of formation that can be seen seen at infrared wavelengths. September 17, 2014  It has been a good week for auroras. Earlier this month active sunspot region 2158 rotated into view and unleashed a series of flares and plasma ejections into the Solar System during its journey across the Sun's disk. In particular, a pair of Coronal Mass Ejections (CMEs) impacted the Earth's magnetosphere toward the end of last week, creating the most intense geomagnetic storm so far this year. Although power outages were feared by some, the most dramatic effects of these impacting plasma clouds were auroras seen as far south as Wisconsin, USA. In the featured image taken last Friday night, rays and sheets of multicolored auroras were captured over Acadia National Park, in Maine, USA. Since another CME plasma cloud is currently approaching the Earth, tonight offers another good chance to see an impressive auroral display. September 16, 2014   Galaxies, stars, and a serene reflecting pool combine to create this memorable land and skyscape. The featured panorama is a 12-image mosaic taken last month from the Salar de Atacama salt flat in northern Chile. The calm water is Laguna Cejar, a salty lagoon featuring a large central sinkhole. On the image left, the astrophotographer's fiancee is seen capturing the same photogenic scene. The night sky is lit up with countless stars, the Large and Small Magellanic Cloud galaxies on the left, and the band of our Milky Way galaxy running diagonally up the right. The Milky Way may appear to be causing havoc at the horizon, but those are just the normal lights of a nearby town. September 15, 2014  Spacecraft Rosetta continues to approach, circle, and map Comet Churyumov-Gerasimenko. Crossing the inner Solar System for ten years to reach the vicinity of the comet last month, the robotic spacecraft continues to image the unusual double-lobed comet nucleus. The reconstructed-color image featured, taken about 10 days ago, indicates how dark this comet nucleus is. On the average, the comet's surface reflects only about four percent of impinging visible light, making it as dark as coal. Comet 67P/Churyumov–Gerasimenko spans about four kilometers in length and has a surface gravity so low that an astronaut could jump off of it. In about two months, Rosetta is scheduled to release the first probe ever to attempt a controlled landing on a comet's nucleus. September 14, 2014  The first hint of what will become of our Sun was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier's list, now known as M27 or the Dumbbell Nebula, is a planetary nebula, the type of nebula our Sun will produce when nuclear fusion stops in its core. M27 is one of the brightest planetary nebulae on the sky, and can be seen toward the constellation of the Fox (Vulpecula) with binoculars. It takes light about 1000 years to reach us from M27, shown above in colors emitted by hydrogen and oxygen. Understanding the physics and significance of M27 was well beyond 18th century science. Even today, many things remain mysterious about bipolar planetary nebula like M27, including the physical mechanism that expels a low-mass star's gaseous outer-envelope, leaving an X-ray hot white dwarf. September 13, 2014  Now, as you sip your cosmic latte you can view 100 Hubble Space Telescope images at the same time. The popular scenes of the cosmos as captured from low Earth orbit are all combined into this single digital presentation. To make it, Hubble's top 100 images were downloaded and resized to identical pixel dimensions. At each point the 100 pixel values were arranged from lowest to highest, and the middle or median value was chosen for the final image. The combined image results in a visual abstraction - light from across the Universe surrounded by darkness. Hubble's Top 100 images: http://www.spacetelescope.org/images/archive/top100/ September 12, 2014  Driven by the explosion of a massive star, supernova remnant Puppis A is blasting into the surrounding interstellar medium about 7,000 light-years away. At that distance, this remarkable false-color exploration of its complex expansion is about 180 light-years wide. It is based on the most complete X-ray data set so far from the Chandra and XMM/Newton observations, and infrared data from the Spitzer Space Telescope. In blue hues, the filamentary X-ray glow is from gas heated by the supernova's shock wave, while the infrared emission shown in red and green is from warm dust. The bright pastel tones trace the regions where shocked gas and warmed dust mingle. Light from the initial supernova itself, triggered by the collapse of the massive star's core, would have reached Earth about 3,700 years ago, though the Puppis A supernova remnant remains a strong source in the X-ray sky. September 11, 2014   You might not guess it, but sunrise was still hours away when this nightscape was taken, a view along the eastern horizon from a remote location in Chile's Atacama desert. Stretching high into the otherwise dark, starry sky the unusually bright conical glow is sunlight though, scattered by dust along the solar system's ecliptic plane . Known as Zodiacal light, the apparition is also nicknamed the "false dawn". Near center, bright star Aldebaran and the Pleiades star cluster seem immersed in the Zodiacal light, with Orion toward the right edge of the frame. Reddish emission from NGC 1499, the California Nebula, can also be seen through the tinge of airglow along the horizon. September 10, 2014  It is not only one of the largest structures known -- it is our home. The just-identified Laniakea Supercluster of galaxies contains thousands of galaxies that includes our Milky Way Galaxy, the Local Group of galaxies, and the entire nearby Virgo Cluster of Galaxies. The colossal supercluster is shown in the above computer-generated visualization, where green areas are rich with white-dot galaxies and white lines indicate motion towards the supercluster center. An outline of Laniakea is given in orange, while the blue dot shows our location. Outside the orange line, galaxies flow into other galatic concentrations. The Laniakea Supercluster spans about 500 million light years and contains about 100,000 times the mass of our Milky Way Galaxy. The discoverers of Laniakea gave it a name that means "immense heaven" in Hawaiian. September 9, 2014  This sky looked delicious. Double auroral ovals were captured above the town lights of Östersund, Sweden, last week. Pictured above, the green ovals occurred lower to the ground than violet aurora rays above, making the whole display look a bit like a cupcake. To top it off, far in the distance, the central band or our Milky Way Galaxy slants down from the upper left. The auroras were caused by our Sun ejecting plasma clouds into the Solar System just a few days before, ionized particles that subsequently impacted the magnetosphere of the Earth. Aurora displays may continue this week as an active sunspot group rotated into view just a few days ago. September 8, 2014  What is so super about tomorrow's supermoon? Tomorrow, a full moon will occur that appears slightly larger and brighter than usual. The reason is that the Moon's fully illuminated phase occurs within a short time from perigee - when the Moon is its closest to the Earth in its elliptical orbit. Although the precise conditions that define a supermoon vary, given one definition, tomorrow's will be the third supermoon of the year -- and the third consecutive month that a supermoon occurs. One reason supermoons are popular is because they are so easy to see -- just go outside and sunset and watch an impressive full moon rise! Since perigee actually occurs today, tonight's sunset moonrise should also be impressive. Pictured above, a supermoon from 2012 is compared to a micromoon -- when a full Moon occurs near the furthest part of the Moon's orbit -- so that it appears smaller and dimmer than usual. Given many definitions, at least one supermoon occurs each year, with the next being 2015 August 30. September 7, 2014 Source: Have you ever watched the Moon rise? The slow rise of a nearly full moon over a clear horizon can be an impressive sight. One impressive moonrise was imaged in early 2013 over Mount Victoria Lookout in Wellington, New Zealand. With detailed planning, an industrious astrophotographer placed a camera about two kilometers away and pointed it across the lookout to where the Moon would surely soon be making its nightly debut. The above single shot sequence is unedited and shown in real time -- it is not a time lapse. People on Mount Victoria Lookout can be seen in silhouette themselves admiring the dawn of Earth's largest satellite. Seeing a moonrise yourself is not difficult: it happens every day, although only half the time at night. Each day the Moon rises about fifty minutes later than the previous day, with a full moon always rising at sunset. A good time to see a moonrise will occur at sunset on Tuesday as the Moon's relative closeness to Earth during a full phase -- called a supermoon -- will cause it to appear slightly larger and brighter than usual. September 6, 2014  Like a rainbow at night, a beautiful moonbow shines above the western horizon in this deserted beach scene from Molokai Island, Hawaii, USA, planet Earth. Captured last June 17 in early morning hours, the lights along the horizon are from Honolulu and cities on the island of Oahu some 30 miles away. So where was the Moon? A rainbow is produced by sunlight internally reflected in rain drops from the direction opposite the Sun back toward the observer. As the light passes from air to water and back to air again, longer wavelengths are refracted (bent) less than shorter ones resulting in the separation of colors. And so the moonbow is produced as raindrops reflect moonlight from the direction opposite the Moon. That puts the Moon directly behind the photographer, still low and rising over the eastern horizon, a few days past its full phase. September 5, 2014  This rich starscape spans nearly 7 degrees on the sky, toward the Sagittarius spiral arm and the center of our Milky Way galaxy. A telescopic mosaic, it features well-known bright nebulae and star clusters cataloged by 18th century cosmic tourist Charles Messier. Still popular stops for skygazers M16, the Eagle (far right), and M17, the Swan (near center) nebulae are the brightest star-forming emission regions. With wingspans of 100 light-years or so, they shine with the telltale reddish glow of hydrogen atoms from over 5,000 light-years away. Colorful open star cluster M25 near the upper left edge of the scene is closer, a mere 2,000 light-years distant and about 20 light-years across. M24, also known as the Sagittarius Star Cloud, crowds in just left of center along the bottom of the frame, fainter and more distant Milky Way stars seen through a narrow window in obscuring fields of interstellar dust. September 4, 2014  On October 19th, a good place to watch Comet Siding Spring will be from Mars. Then, this inbound visitor (C/2013 A1) to the inner solar system, discovered in January 2013 by Robert McNaught at Australia's Siding Spring Observatory, will pass within 132,000 kilometers of the Red Planet. That's a near miss, equivalent to just over 1/3 the Earth-Moon distance. Great views of the comet for denizens of planet Earth's southern hemisphere are possible now, though. This telescopic snapshot from August 29 captured the comet's whitish coma and arcing dust tail sweeping through southern skies. The fabulous field of view includes, the Small Magellanic Cloud and globular star clusters 47 Tucanae (right) and NGC 362 (upper left). Worried about all those spacecraft in Martian orbit? Streaking dust particles from the comet could pose a danger and controllers plan to position Mars orbiters on the opposite side of the planet during the comet's close flyby. September 3, 2014  To some, the outline of the open cluster of stars M6 resembles a butterfly. M6, also known as NGC 6405, spans about 20 light-years and lies about 2,000 light years distant. M6, pictured above, can best be seen in a dark sky with binoculars towards the constellation of the Scorpion (Scorpius), coving about as much of the sky as the full moon. Like other open clusters, M6 is composed predominantly of young blue stars, although the brightest star is nearly orange. M6 is estimated to be about 100 million years old. Determining the distance to clusters like M6 helps astronomers calibrate the distance scale of the universe. September 2, 2014  How different are space and time at very small scales? To explore the unfamiliar domain of the miniscule Planck scale -- where normally unnoticeable quantum effects might become dominant -- a newly developed instrument called the Fermilab Holometer has begun operating at the Fermi National Accelerator Laboratory (Fermilab) near Chicago, Illinois, USA. The instrument seeks to determine if slight but simultaneous jiggles of a mirror in two directions expose a fundamental type of holographic noise that always exceeds a minimum amount. Pictured above is one of the end mirrors of a Holometer prototype. Although the discovery of holographic noise would surely be groundbreaking, the dependence of such noise on a specific laboratory length scale would surprise some spacetime enthusiasts. One reason for this is the Lorentz Invariance postulate of Einstein's special relativity, which states that all length scales should appear contracted to a relatively moving observer -- even the diminutive Planck length. Still, the experiment is unique and many are curious what the results will show. September 1, 2014  Why would the sky look like a giant target? Airglow. Following a giant thunderstorm over Bangladesh in late April, giant circular ripples of glowing air appeared over Tibet, China, as pictured above. The unusual pattern is created by atmospheric gravity waves, waves of alternating air pressure that can grow with height as the air thins, in this case about 90 kilometers up. Unlike auroras powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction. More typically seen near the horizon, airglow keeps the night sky from ever being completely dark. August 31, 2014  How was this picture taken? Usually, pictures of the shuttle, taken from space, are snapped from the space station. Commonly, pictures of the space station are snapped from the shuttle. How, then, can there be a picture of both the shuttle and the station together, taken from space? The answer is that during the Space Shuttle Endeavour's last trip to the International Space Station in 2011 May, a supply ship departed the station with astronauts that captured a series of rare views. The supply ship was the Russian Soyuz TMA-20 which landed in Kazakhstan later that day. The above spectacular image well captures the relative sizes of the station and docked shuttle. Far below, clouds of Earth are seen above a blue sea. August 30, 2014  Look up in New Zealand's Hollow Hill Cave and you might think you see a familiar starry sky. And that's exactly what Arachnocampa luminosa are counting on. Captured in this long exposure, the New Zealand glowworms scattered across the cave ceiling give it the inviting and open appearance of a clear, dark night sky filled with stars. Unsuspecting insects fooled into flying too far upwards get trapped in sticky snares the glowworms create and hang down to catch food. Of course professional astronomers wouldn't be so easily fooled, although that does look a lot like the Coalsack Nebula and Southern Cross at the upper left ... Comparison Photo: http://apod.nasa.gov/apod/ap070517.html August 29, 2014   Open star cluster NGC 7380 is still embedded in its natal cloud of interstellar gas and dust popularly known as the Wizard Nebula. Seen with foreground and background stars along the plane of our Milky Way galaxy it lies some 8,000 light-years distant, toward the constellation Cepheus. A full moon would easily fit inside this telescopic view of the 4 million year young cluster and associated nebula, normally much too faint to be seen by eye. Made with telescope and camera firmly planted on Earth, the image reveals multi light-year sized shapes and structures within the Wizard in a color palette made popular in Hubble Space Telescope images. Recorded with narrowband filters, the visible wavelength light from the nebula's hydrogen, oxygen, and sulfur atoms is transformed into green, blue, and red colors in the final digital composite. But there is still a trick up the Wizard's sleeve. Sliding your cursor over the image (or following this link) will make the stars disappear, leaving only the cosmic gas and dust of the Wizard Nebula. August 28, 2014  The beautiful Trifid Nebula, also known as Messier 20, is easy to find with a small telescope in the nebula rich constellation Sagittarius. About 5,000 light-years away, the colorful study in cosmic contrasts shares this well-composed, nearly 1 degree wide field with open star cluster Messier 21 (top right). Trisected by dust lanes the Trifid itself is about 40 light-years across and a mere 300,000 years old. That makes it one of the youngest star forming regions in our sky, with newborn and embryonic stars embedded in its natal dust and gas clouds. Estimates of the distance to open star cluster M21 are similar to M20's, but though they share this gorgeous telescopic skyscape there is no apparent connection between the two. In fact, M21's stars are much older, about 8 million years old. August 27, 2014  The Milky Way was not created by an evaporating lake. The colorful pool of water, about 10 meters across, is known as Silex Spring and is located in Yellowstone National Park in Wyoming, USA. Illuminated artificially, the colors are caused by layers of bacteria that grow in the hot spring. Steam rises off the spring, heated by a magma chamber deep underneath known as the Yellowstone hotspot. Unrelated and far in the distance, the central band of our Milky Way Galaxy arches high overhead, a band lit by billions of stars. The above picture is a 16-image panorama taken late last month. If the Yellowstone hotspot causes another supervolcanic eruption as it did 640,000 years ago, a large part of North America would be affected. August 26, 2014 What would it look like to fly past Triton, the largest moon of planet Neptune? Only one spacecraft has ever done this -- and now, for the first time, images of this dramatic encounter have been gathered into a movie. On 1989 August 25, the Voyager 2 spacecraft shot through the Neptune system with cameras blazing. Triton is slightly smaller than Earth's Moon but has ice volcanoes and a surface rich in frozen nitrogen. The first sequence in the video shows Voyager's approach to Triton, which, despite its unusual green tint, appears in approximately true color. The mysterious terrain seen under the spacecraft soon changed from light to dark, with the terminator of night soon crossing underneath. After closest approach, Voyager pivoted to see the departing moon, now visible as a diminishing crescent. Next July, assuming all goes well, the robotic New Horizons spacecraft will make a similar flight past Pluto, an orb of similar size to Triton. August 25, 2014  Why does this galaxy have such a long tail? In this stunning vista, based on image data from the Hubble Legacy Archive, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic tadpole is a mere 420 million light-years distant toward the northern constellation Draco. Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story goes that a more compact intruder galaxy crossed in front of Arp 188 - from right to left in this view - and was slung around behind the Tadpole by their gravitational attraction. During the close encounter, tidal forces drew out the spiral galaxy's stars, gas, and dust forming the spectacular tail. The intruder galaxy itself, estimated to lie about 300 thousand light-years behind the Tadpole, can be seen through foreground spiral arms at the upper right. Following its terrestrial namesake, the Tadpole Galaxy will likely lose its tail as it grows older, the tail's star clusters forming smaller satellites of the large spiral galaxy. August 24, 2014  What's that dot on the Sun? If you look closely, it is almost perfectly round. The dot is the result of an unusual type of solar eclipse that occurred in 2006. Usually it is the Earth's Moon that eclipses the Sun. This time, the planet Mercury took a turn. Like the approach to New Moon before a solar eclipse, the phase of Mercury became a continually thinner crescent as the planet progressed toward an alignment with the Sun. Eventually the phase of Mercury dropped to zero and the dark spot of Mercury crossed our parent star. The situation could technically be labeled a Mercurian annular eclipse with an extraordinarily large ring of fire. From above the cratered planes of the night side of Mercury, the Earth appeared in its fullest phase. Hours later, as Mercury continued in its orbit, a slight crescent phase appeared again. The next Mercurian solar eclipse will occur in 2016. August 23, 2014  The city of Veszprem, Hungary was only briefly haunted by this mysterious spectre. On the morning of August 11, its monstrous form hovered in the mist above municipal buildings near the town center. A clue to its true identity is offered by the photographer, though, who reports he took the picture from the top of a twenty story building with the rising Sun directly at his back. That special geometry suggests this is an example of an atmospheric phenomenon called the Glory or sometimes "the Spectre of the Brocken". Also seen from mountain tops and airplanes when looking opposite the Sun, the dramatic apparition is the observer's shadow on clouds or fog, the small droplets of water scattering light back towards the Sun through complex internal reflections. Careful night sky watchers can also encounter this spectre's analog in astronomy, a brightening of zodiacal light opposite the Sun known as the gegenschein. August 22, 2014  On July 13th, a good place to watch Comet Jacques was from Venus. Then, the recently discovered visitor (C/2014 E2) to the inner solar system passed within about 14.5 million kilometers of our sister planet. Still, the outbound comet will pass only 84 million kilometers from our fair planet on August 28 and is already a fine target for telescopes and binoculars. Two days ago, Jacques' greenish coma and straight and narrow ion tail were captured in this telescopic snapshot, a single 2 minute long exposure with a modified digital camera. The comet is flanked by IC 1805 and IC 1848, also known as Cassiopeia's Heart and Soul Nebulae. If you're stuck on planet Earth this weekend you can hunt for Comet Jacques in evening skies, or spot a Venus, Jupiter, crescent Moon triangle before the dawn. August 21, 2014  On Monday morning, Venus and Jupiter gathered close in dawn skies, for some separated by about half the width of a full moon. It was their closest conjunction since 2000, captured here above the eastern horizon before sunrise. The serene and colorful view is from Istia beach near the city of Capoliveri on the island of Elba. Distant lights and rolling hills are along Italy's Tuscan coast. Of course, the celestial pair soon wandered apart. Brighter Venus headed lower, toward the eastern horizon and the glare of the Sun, while Jupiter continues to rise a little higher now in the sky near dawn. The two brightest planets meet again next June 30th, in the evening twilight above the western horizon. August 20, 2014  The center of the Lagoon Nebula is a whirlwind of spectacular star formation. Visible near the image center, at least two long funnel-shaped clouds, each roughly half a light-year long, have been formed by extreme stellar winds and intense energetic starlight. The tremendously bright nearby star, Hershel 36, lights the area. Walls of dust hide and redden other hot young stars. As energy from these stars pours into the cool dust and gas, large temperature differences in adjoining regions can be created generating shearing winds which may cause the funnels. This picture, spanning about 5 light years, combines images taken by the orbiting Hubble Space Telescope. The Lagoon Nebula, also known as M8, lies about 5,000 light years distant toward the constellation of Sagittarius. August 19, 2014  Where should Philae land? As ESA's robotic spacecraft Rosetta circles toward Comet 67P/ Churyumov-Gerasimenko, a decision must eventually be made as to where its mechanical lander should attempt to touch-down. Reaching the comet earlier this month, Rosetta is sending back detailed pictures of the comet's unusual nucleus from which a smooth landing site will be selected. Pictured above, near the image top, the head of the comet's nucleus shows rugged grooves, while near the image bottom, the body shows a patch-work of areas sometimes separated by jagged hills. Some of the patch-work areas apparent on both the head and body seem to have fields of relatively smooth terrain. In the connecting area called the neck, however, visible across the image center, a relatively large swath of light-colored smooth terrain appears, punctuated occasionally by large boulders. Rosetta is scheduled to release Philae toward the dark mountain-sized comet nucleus with an anticipated landing date in November. August 18, 2014  Both land and sky were restless. The unsettled land included erupting Mount Semeru in the distance, the caldera of steaming Mount Bromo on the left, flowing fog, and the lights of moving cars along roads that thread between hills and volcanoes in Bromo Tengger Semeru National Park in East Java, Indonesia. The stirring sky included stars circling the South Celestial Pole and a meteor streaking across the image right. The above 270-image composite was taken from King Kong Hill in mid-June over two hours, with a rising Moon lighting the landscape. August 17, 2014  It was visible around the world. The sunset conjunction of Jupiter and Venus in 2012 was visible almost no matter where you lived on Earth. Anyone on the planet with a clear western horizon at sunset could see them. Pictured above in 2012, a creative photographer traveled away from the town lights of Szubin, Poland to image a near closest approach of the two planets. The bright planets were separated only by three degrees and his daughter struck a humorous pose. A faint red sunset still glowed in the background. Early tomorrow (Monday) morning, the two planets will pass even closer -- only 0.2 degrees apart as visible from some locations -- just before sunrise. August 16, 2014  Last January, telescopes in observatories around planet Earth were eagerly used to watch the rise of SN 2014J, a bright supernova in nearby galaxy M82. Still, the most important observations may have been from orbit where the Chandra X-ray Observatory saw nothing. Identified as a Type Ia supernova, the explosion of SN2014J was thought to be triggered by the buildup of mass on a white dwarf star steadily accreting material from a companion star. That model predicts X-rays would be generated when the supernova blastwave struck the material left surrounding the white dwarf. But no X-rays were seen from the supernova. The mostly blank close-ups centered on the supernova's position are shown in the before and after inset panels of Chandra's false color X-ray image of the M82 galaxy. The stunning lack of X-rays from SN 2014J will require astronomers to explore other models to explain what triggers these cosmic explosions. August 15, 2014  Bright moonlight from a Full Moon near perigee illuminates the night and casts shadows in this skyscape from central Iran. Taken on August 12, near the peak of the annual Perseid meteor shower the exposure also captures a bright and colorful perseid streak above the shady tree in the foreground. This year the super moonlight interfered with meteor watching into the early morning hours, overwhelming the trails from many fainter perseids in the shower. Brighter perseids like this one were still visible though, their trails pointing back to the heroic constellation Perseus outlined at the right. Swept up as planet Earth orbits through dust left behind from periodic comet Swift-Tuttle, the cosmic grains that produce perseid meteors enter the atmosphere at nearly 60 kilometers per second, heated to incandesence and vaporized at altitudes of about 100 kilometers. Next year, Perseid meteors will flash through dark skies under a New Moon. August 14, 2014  Big, bright, and beautiful, a Full Moon near perigee, the closest point in its elliptical orbit around our fair planet, rose on August 10. This remarkable picture records the scene with a dreamlike quality from the east coast of the United States. The picture is actually a composite of 10 digital frames made with exposures from 1/500th second to 1 second long, preserving contrast and detail over a much wider than normal range of brightness. At a perigee distance of a mere 356,896 kilometers, August's Full Moon was the closest, and so the largest and most super, of the three Full Moons nearest perigee in 2014 now popularly known as supermoons. But if you missed August's super supermoon, the next not-quite-so supermoon will be September 8. Then, near the full lunar phase the Moon's perigee will be a slightly more distant 358,387 kilometers. That's only about 0.4 percent less super (farther and smaller) than the super supermoon. August 13, 2014  It is a familiar sight to sky enthusiasts with even a small telescope. There is much more to the Ring Nebula (M57), however, than can be seen through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. This remarkable composite image includes narrowband hydrogen image, visible light emission, and infrared light emission. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from a dying, sun-like star. The Ring Nebula is about 2,000 light-years away toward the musical constellation Lyra. August 12, 2014  What's happened in Hebes Chasma on Mars? Hebes Chasma is a depression just north of the enormous Valles Marineris canyon. Since the depression is unconnected to other surface features, it is unclear where the internal material went. Inside Hebes Chasma is Hebes Mensa, a 5 kilometer high mesa that appears to have undergone an unusual partial collapse -- a collapse that might be providing clues. The above image, taken by the robotic Mars Express spacecraft currently orbiting Mars, shows great details of the chasm and the unusual horseshoe shaped indentation in the central mesa. Material from the mesa appears to have flowed onto the floor of the chasm, while a possible dark layer appears to have pooled like ink on a downslope landing. A recent hypothesis holds that salty rock composes some lower layers in Hebes Chasma, with the salt dissolving in melted ice flows that drained through holes into an underground aquifer. August 11, 2014 What does it look like to approach a comet? Early this month humanity received a new rendition as the robotic Rosetta spacecraft went right up to -- and began orbiting -- the nucleus of Comet 67P/Churyumov-Gerasimenko. This approach turned out to be particularly fascinating because the comet nucleus first revealed itself to have an unexpected double structure, and later showed off an unusual and craggily surface. The above 101-frame time-lapse video details the approach of the spacecraft from August 1 through August 6. The icy comet's core is the size of a mountain and rotates every 12.7 hours. Rosetta's images and data may shed light on the origin of comets and the early history of our Solar System. Later this year, Rosetta is scheduled to release the Philae lander, which will attempt to land on Comet Churyumov–Gerasimenko's periphery and harpoon itself to the surface. August 10, 2014  Denizens of planet Earth typically watch meteor showers by looking up. But this remarkable view, captured on August 13, 2011 by astronaut Ron Garan, caught a Perseid meteor by looking down. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is right of frame center, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at a meteor shower? You're in luck, as the 2014 Perseids meteor shower peaks this week. Unfortunately, the fainter meteors in this year's shower will be hard to see in a relatively bright sky lit by the glow of a nearly full Moon. August 9, 2014  What shines in the world at night? Just visible to the eye, a rare electric blue glow spread along the shores of Victoria Lake on January 16, 2013. Against reflections of a light near the horizon, this digitally stacked long exposure recorded the bioluminescence of noctiluca scintillans, plankton stimulated by the lapping waves. Above, the night skies of the Gippsland Lakes region, Victoria, Australia shine with a fainter greenish airglow. Oxygen atoms in the upper atmosphere, initially excited by ultraviolet sunlight, produce the more widely seen fading atmospheric chemiluminescence. Washed out by the Earth's rotation, the faint band of the southern summer Milky Way stretches from the horizon as star trails circle the South Celestial Pole. August 8, 2014  Big, beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo. We see the disk of the nearby island universe tilted towards our line of sight. Orientation and composition give a strong sense of depth to this colorful galaxy portrait that covers an area about the angular size of the full moon. This giant galaxy's yellowish core is dominated by the light from old, cool stars. Beyond the core, spiral arms filled with young blue star clusters and pinkish star forming regions sweep past a smaller satellite galaxy at the lower left, reminiscent of the Milky Way's satellite galaxy the Large Magellanic Cloud. August 7, 2014  On August 3rd, the Rosetta spacecraft's narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target. The curious double-lobed shape of the nucleus is revealed in amazing detail at an image resolution of 5.3 meters per pixel. About 4 kilometers across, the comet nucleus is presently just over 400 million kilometers from Earth, between the orbits of Jupiter and Mars. Now the first spacecraft to achieve a delicate orbit around a comet, Rosetta will swing to within 50 kilometers and closer in the coming weeks, identifiying candidate sites for landing its probe Philae later this year. August 6, 2014  Acquiring its first sunlit views of far northern Saturn in late 2012, the Cassini spacecraft's wide-angle camera recorded this stunning, false-color image of the ringed planet's north pole. The composite of near-infrared image data results in red hues for low clouds and green for high ones, giving the Saturnian cloudscape a vivid appearance. Enormous by terrestrial standards, Saturn's north polar hurricane-like storm is deep, red, and about 2,000 kilometers wide. Clouds at its outer edge travel at over 500 kilometers per hour. Other atmospheric vortices also swirl inside the large, yellowish green, six-sided jet stream known as the hexagon. Beyond the cloud tops at the upper right, arcs of the planet's eye-catching rings appear bright blue. August 5, 2014  No place on Earth was safe. Four billion years ago, during the Hadean eon, our Solar System was a dangerous shooting gallery of large and dangerous rocks and ice chunks. Recent examination of lunar and Earth bombardment data indicate that the entire surface of the Earth underwent piecemeal upheavals, hiding our globe's ancient geologic history, and creating a battered world with no remaining familiar land masses. The rain of devastation made it difficult for any life to survive, although bacteria that could endure high temperatures had the best chance. Oceans thought to have formed during this epoch would boil away after particularly heavy impacts, only to reform again. The above artist's illustration depicts how Earth might have looked during this epoch, with circular impact features dotting the daylight side, and hot lava flows visible in the night. One billion years later, in a calmer Solar System, Earth's first supercontinent formed. August 4, 2014  Why does Enceladus have ice plumes? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, remained a topic of research. A leading hypothesis held that the source might originate from a deep underground sea, but another hypothesis indicated that it might just be ice melted off walls of deep rifts by the moon's tidal flexing and heating. Pictured above, the textured surface of Enceladus is visible in the foreground, while rows of plumes rise from ice fractures in the distance. These jets are made more visible by the Sun angle and the encroaching shadow of night. Recent study of over a hundred images like this -- of geysers crossing Enceladus' South Pole, together with regional heat maps, indicate that these plumes likely originate from a hidden sea, incresaing the chance that this frosty globe might be harboring life. August 3, 2014  What's that approaching? Astronauts on board the International Space Station first saw it in early 2010 far in the distance. Soon it enlarged to become a dark silhouette. As it came even closer, the silhouette appeared to be a spaceship. Finally, the object revealed itself to be the Space Shuttle Endeavour, and it soon docked as expected with the Earth-orbiting space station. Pictured above, Endeavour was imaged near Earth's horizon as it approached, where several layers of the Earth's atmosphere were visible. Directly behind the shuttle is the mesosphere, which appears blue. The atmospheric layer that appears white is the stratosphere, while the orange layer is Earth's Troposphere. This shuttle mission, began with a dramatic night launch. Tasks completed during this shuttle's visit to the ISS included the delivery of the Tranquility Module which contained a cupola bay window complex that allows even better views of spaceships approaching and leaving the space station. August 2, 2014  These clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula, NGC 7023 is not the only nebula in the sky to evoke the imagery of flowers, though. Still, this deep telescopic view shows off the Iris Nebula's range of colors and symmetries in impressive detail. Within the Iris, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the dusty clouds glow with a faint reddish photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. Infrared observations indicate that this nebula may contain complex carbon molecules known as PAHs. The pretty blue petals of the Iris Nebula span about six light-years. August 1, 2014  An alluring night skyscape, this scene looks west across the Grand Teton National Park, Wyoming, USA, Planet Earth. The Snake River glides through the foreground, while above the Tetons' rugged mountain peaks the starry sky is laced with exceptionally strong red and green airglow. That night, the luminous atmospheric glow was just faintly visible to the eye, its color and wavey structure captured only by a sensitive digital camera. In fact, this contemporary digital photograph matches the location and perspective of a well-known photograph from 1942 - The Tetons and The Snake River , by Ansel Adams, renown photographer of the American West. Adams' image is one of 115 images stored on the Voyager Golden Record. Humanity's message in a bottle, golden records were onboard both Voyager 1 and Voyager 2 spacecraft, launched in 1977 and now headed toward interstellar space. July 31, 2014  Transfusing sunlight through a a still dark sky, this exceptional display of noctilucent clouds was captured earlier this month above the island of Gotland, Sweden. From the edge of space, about 80 kilometers above Earth's surface, the icy clouds reflect sunlight even though the Sun itself is below the horizon as seen from the ground. Usually spotted at high latitudes in summer months the night shining clouds made a strong showing this July. Also known as polar mesopheric clouds they are understood to form as water vapor driven into the cold upper atmosphere condenses on the fine dust particles supplied by disintegrating meteors or volcanic ash. NASA's AIM mission provides daily projections of noctilucent clouds as seen from space. July 30, 2014  Andromeda is the nearest major galaxy to our own Milky Way Galaxy. Our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it. The several distinct stars that surround Andromeda's image are actually stars in our Galaxy that are well in front of the background object. Andromeda is frequently referred to as M31 since it is the 31st object on Messier's list of diffuse sky objects. M31 is so distant it takes about two million years for light to reach us from there. Although visible without aid, the above image of M31 was taken with a standard camera through a small telescope. Much about M31 remains unknown, including how it acquired its unusual double-peaked center. July 29, 2014  To some, it may look like a portal into the distant universe. To others, it may appear as the eye of a giant. Given poetic license, both are correct. Pictured above is a standard fisheye view of the sky -- but with an unusual projection. The view is from a perch in New Zealand called Te Mata Peak, a name that translates from the Maori language as "Sleeping Giant". The wondrous panorama shows the band of our Milky Way Galaxy right down the center of the sky, with the Large and Small Magellanic Clouds visible to the right. The red hue is atmospheric airglow that surprised the photographer as it was better captured by the camera than the eye. The above image was taken two weeks ago as the photographer's sister, on the left, and an acquaintance peered into the sky portal. July 28, 2014  The clouds surrounding the star system Rho Ophiuchi compose one of the One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming. Light takes about 1,500 years to reach us from the Horsehead Nebula. The above image is a digital combination of images taken in blue, green, red, and hydrogen-alpha light from the Argentina, and an image taken in infrared light by the orbiting Hubble Space Telescope. July 27, 2014  The clouds surrounding the star system Rho Ophiuchi compose one of the closest star forming regions. Rho Ophiuchi itself is a binary star system visible in the light-colored region on the image right. The star system, located only 400 light years away, is distinguished by its colorful surroundings, which include a red emission nebula and numerous light and dark brown dust lanes. Near the upper right of the Rho Ophiuchi molecular cloud system is the yellow star Antares, while a distant but coincidently-superposed globular cluster of stars, M4, is visible between Antares and the red emission nebula. Near the image bottom lies IC 4592, the Blue Horsehead nebula. The blue glow that surrounds the Blue Horsehead's eye -- and other stars around the image -- is a reflection nebula composed of fine dust. On the above image left is a geometrically angled reflection nebula cataloged as Sharpless 1. Here, the bright star near the dust vortex creates the light of surrounding reflection nebula. Although most of these features are visible through a small telescope pointed toward the constellations of Ophiuchus, Scorpius, and Sagittarius, the only way to see the intricate details of the dust swirls, as featured above, is to use a long exposure camera. July 26, 2014  Shiny NGC 253 is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Dollar Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. First swept up in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 10 million light-years away. About 70 thousand light-years across, NGC 253 is the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group of Galaxies. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions in this sharp color image. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massives black hole near the galaxy's center. July 25, 2014  The Crab Pulsar, a city-sized, magnetized neutron star spinning 30 times a second, lies at the center of this tantalizing wide-field image of the Crab Nebula. A spectacular picture of one of our Milky Way's supernova remnants, it combines optical survey data with X-ray data from the orbiting Chandra Observatory. The composite was created as part of a celebration of Chandra's 15 year long exploration of the high energy cosmos. Like a cosmic dynamo the pulsar powers the X-ray and optical emission from the nebula, accelerating charged particles to extreme energies to produce the jets and rings glowing in X-rays. The innermost ring structure is about a light-year across. With more mass than the Sun and the density of an atomic nucleus, the spinning pulsar is the collapsed core of the massive star that exploded, while the nebula is the expanding remnant of the star's outer layers. The supernova explosion was witnessed in the year 1054. July 24, 2014  This alluring all-skyscape was taken 5,100 meters above sea level, from the Chajnantor Plateau in the Chilean Andes. Viewed through the site's rarefied atmosphere at about 50% sea level pressure, the gorgeous Milky Way stretches through the scene. Its cosmic rifts of dust, stars, and nebulae are joined by Venus, a brilliant morning star immersed in a strong band of predawn Zodiacal light. Still not completely dark even at this high altitude, the night sky's greenish cast is due to airglow emission from oxygen atoms. Around the horizon the dish antenna units of the Atacama Large Millimeter/submillimeter Array, ALMA, explore the universe at wavelengths over 1,000 times longer than visible light. July 23, 2014  Why does this starfield photograph resemble an impressionistic painting? The effect is created not by digital trickery but by large amounts of interstellar dust. Dust, minute globs rich in carbon and similar in size to cigarette smoke, frequently starts in the outer atmospheres of large, cool, young stars. The dust is dispersed as the star dies and grows as things stick to it in the interstellar medium. Dense dust clouds are opaque to visible light and can completely hide background stars. For less dense clouds, the capacity of dust to preferentially reflect blue starlight becomes important, effectively blooming the stars blue light out and marking the surrounding dust. Nebular gas emissions, typically brightest in red light, can combine to form areas seemingly created on an artist's canvas. Photographed above is the central part of the nebula IC 4603 surrounding the bright star SAO 184376 (actually 8th magnitude) which mostly illuminates the blue reflection nebula. IC 4603 can be seen near the very bright star Antares (1st magnitude) toward the constellation of Ophiuchus. July 22, 2014  Yes, but have you ever seen aurora from a cave? To capture this fascinating juxtaposition between below and above, astrophotographer Bjargmundsson spent much of a night alone in the kilometer-long Raufarhólshellir lava cave in Iceland during late March. There, he took separate images of three parts of the cave using a strobe for illumination. He also took a deep image of the sky to capture faint aurora, and digitally combined the four images later. The 4600-year old lava tube has several skylights under which stone rubble and snow have accumulated. Oh -- the person standing on each mound -- it's the artist. July 21, 2014  Why does this comet's nucleus have two components? The surprising discovery that Comet 67P/Churyumov–Gerasimenko has a double nucleus came late last week as ESA's robotic interplanetary spacecraft Rosetta continued its approach toward the ancient comet's core. Speculative ideas on how the double core was created include, currently, that Comet Churyumov–Gerasimenko is actually the result of the merger of two comets, that the comet is a loose pile of rubble pulled apart by tidal forces, that ice evaporation on the comet has been asymmetric, or that the comet has undergone some sort of explosive event. Pictured above, the comet's unusual 5-km sized comet nucleus is seen rotating over the course of a few hours, with each frame taken 20-minutes apart. Better images -- and hopefully more refined theories -- are expected as Rosetta is on track to enter orbit around Comet Churyumov–Gerasimenko's nucleus early next month, and by the end of the year, if possible, land a probe on it. July 20, 2014  What's happened to our Sun? Nothing very unusual -- it just threw a filament. Toward the middle of 2012, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME). The filament had been held up for days by the Sun's ever changing magnetic field and the timing of the eruption was unexpected. Watched closely by the Sun-orbiting Solar Dynamics Observatory, the resulting explosion shot electrons and ions into the Solar System, some of which arrived at Earth three days later and impacted Earth's magnetosphere, causing visible aurorae. Loops of plasma surrounding an active region can be seen above the erupting filament in the ultraviolet image. Over the past week the number of sunspots visible on the Sun unexpectedly dropped to zero, causing speculation that the Sun has now passed a very unusual solar maximum, the time in the Sun's 11-year cycle when it is most active. July 19, 2014  In this beach and skyscape from Alicante, Spain, July's Full Moon shines in the dark blue twilight, its reflection coloring the Mediterranean waters. Near the horizon, the moonlight is reddened by its long path through the atmosphere, but this Full Moon was also near perigee, the closest point to Earth along the Moon's elliptical orbit. That made it a Supermoon, a mighty 14% larger and 30% brighter than a Full Moon at apogee, the Moon's farthest orbital swing. Of course, most warm summer nights are a good time to enjoy a family meal oceanside, but what fish do you catch on the night of a Supermoon? They must be Moon breams ... July 18, 2014  A mysterious, squid-like apparition, this nebula is very faint, but also very large in planet Earth's sky. In the mosaic image, composed with narrowband data from the 2.5 meter Isaac Newton Telescope, it spans some 2.5 full moons toward the constellation Cepheus. Recently discovered by French astro-imager Nicolas Outters, the remarkable nebula's bipolar shape and emission are consistent with it being a planetary nebula, the gaseous shroud of a dying sun-like star, but its actual distance and origin are unknown. A new investigation suggests Ou4 really lies within the emission region SH2-129 some 2,300 light-years away. Consistent with that scenario, the cosmic squid would represent a spectacular outflow of material driven by a triple system of hot, massive stars, cataloged as HR8119, seen near the center of the nebula. If so, this truly giant squid nebula would physically be nearly 50 light-years across. July 17, 2014  If you're looking for something to print with that new 3D printer, try out a copy of the Homunculus Nebula. The dusty, bipolar cosmic cloud is around 1 light-year across but is slightly scaled down for printing to about 1/4 light-nanosecond or 80 millimeters. The full scale Homunculus surrounds Eta Carinae, famously unstable massive stars in a binary system embedded in the extensive Carina Nebula about 7,500 light-years distant. Between 1838 and 1845, Eta Carinae underwent the Great Eruption becoming the second brightest star in planet Earth's night sky and ejecting the Homunculus Nebula. The new 3D model of the still expanding Homunculus was created by exploring the nebula with the European Southern Observatory's VLT/X-Shooter. That instrument is capable of mapping the velocity of molecular hydrogen gas through the nebula's dust at a fine resolution. It reveals trenches, divots and protrusions, even in the dust obscured regions that face away from Earth. Eta Carinae itself still undergoes violent outbursts, a candidate to explode in a spectacular supernova in the next few million years. July 16, 2014  What happened to half of Saturn? Nothing other than Earth's Moon getting in the way. As pictured above on the far right, Saturn is partly eclipsed by a dark edge of a Moon itself only partly illuminated by the Sun. This year the orbits of the Moon and Saturn have led to an unusually high number of alignments of the ringed giant behind Earth's largest satellite. Technically termed an occultation, the above image captured one such photogenic juxtaposition from Buenos Aires, Argentina that occurred early last week. Visible to the unaided eye but best viewed with binoculars, there are still four more eclipses of Saturn by our Moon left in 2014. The next one will be on August 4 and visible from Australia, while the one after will occur on August 31 and be visible from western Africa at night but simultaneously from much of eastern North America during the day. July 15, 2014  Why is there a blue bridge of stars across the center of this galaxy cluster? First and foremost the cluster, designated SDSS J1531+3414, contains many large yellow elliptical galaxies. The cluster's center, as pictured above by the Hubble Space Telescope, is surrounded by many unusual, thin, and curving blue filaments that are actually galaxies far in the distance whose images have become magnified and elongated by the gravitational lens effect of the massive cluster. More unusual, however, is a squiggly blue filament near the two large elliptical galaxies at the cluster center. Close inspection of the filament indicates that it is most likely a bridge created by tidal effects between the two merging central elliptical galaxies rather than a background galaxy with an image distorted by gravitational lensing. The knots in the bridge are condensation regions that glow blue from the light of massive young stars. The central cluster region will likely undergo continued study as its uniqueness makes it an interesting laboratory of star formation. July 14, 2014  Gusting solar winds and blasts of charged particles from the Sun resulted in several rewarding nights last December for those anticipating auroras. The above image captured dramatic auroras stretching across a sky near the town of Yellowknife in northern Canada. The auroras were so bright that they not only inspired awe, but were easily visible on an image exposure of only 1.3 seconds. A video taken concurrently shows the dancing sky lights evolving in real time as tourists, many there just to see auroras, respond with cheers. The conical dwellings on the image right are teepees, while far in the background, near the image center, is the constellation of Orion. Video: http://vimeo.com/85070976 July 13, 2014  NGC 2818 is a beautiful planetary nebula, the gaseous shroud of a dying sun-like star. It could well offer a glimpse of the future that awaits our own Sun after spending another 5 billion years or so steadily using up hydrogen at its core, and then finally helium, as fuel for nuclear fusion. Curiously, NGC 2818 seems to lie within an open star cluster, NGC 2818A, that is some 10,000 light-years distant toward the southern constellation Pyxis (the Compass). At the distance of the star cluster, the nebula would be about 4 light-years across. But accurate velocity measurements show that the nebula's own velocity is very different from the cluster's member stars. The result is strong evidence that NGC 2818 is only by chance found along the line of sight to the star cluster and so may not share the cluster's distance or age. The Hubble image is a composite of exposures through narrow-band filters, presenting emission from nitrogen, hydrogen, and oxygen atoms in the nebula as red, green, and blue hues. July 12, 2014  A new star, likely the brightest supernova in recorded human history, lit up planet Earth's sky in the year 1006 AD. The expanding debris cloud from the stellar explosion, found in the southerly constellation of Lupus, still puts on a cosmic light show across the electromagnetic spectrum. In fact, this composite view includes X-ray data in blue from the Chandra Observatory, optical data in yellowish hues, and radio image data in red. Now known as the SN 1006 supernova remnant, the debris cloud appears to be about 60 light-years across and is understood to represent the remains of a white dwarf star. Part of a binary star system, the compact white dwarf gradually captured material from its companion star. The buildup in mass finally triggered a thermonuclear explosion that destroyed the dwarf star. Because the distance to the supernova remnant is about 7,000 light-years, that explosion actually happened 7,000 years before the light reached Earth in 1006. Shockwaves in the remnant accelerate particles to extreme energies and are thought to be a source of the mysterious cosmic rays. July 11, 2014  In this composite cityscape, dawn's first colors backdrop the lights along Brisbane's skyline at the southeastern corner of Queensland, Australia, planet Earth. Using a solar filter, additional exposures made every 3.5 minutes follow the winter sunrise on July 8 as planet-sized sunspots cross the visible solar disk. The sunspots mark solar active regions with convoluted magnetic fields. Even as the maximum in the solar activity cycle begins to fade, the active regions produce intense solar flares and eruptions launching coronal mass ejections (CMEs), enormous clouds of energetic particles, into our fair solar system. July 10, 2014  This scene from the early morning hours of July 3 looks out across the River Thames from the Westminster Bridge. Part of a luminous timelapse video (vimeo), the frame captures a sight familiar in London, the nighttime glow of the London Eye. But a not-so-familiar sight is shining in the still dark sky above, widespread noctilucent clouds. From the edge of space, about 80 kilometers above Earth's surface, the icy clouds can still reflect sunlight even though the Sun itself is below the horizon as seen from the ground. Usually spotted at high latitudes in summer months the diaphanous apparitions are also known as polar mesospheric clouds. The seasonal clouds are understood to form as water vapor driven into the cold upper atmosphere condenses on the fine dust particles supplied by disintegrating meteors or volcanic ash. NASA's AIM mission provides daily projections of the noctilucent clouds as seen from space. July 9, 2014  This planet is only 16 light years away -- could it harbor life? Recently discovered exoplanet Gliese 832c has been found in a close orbit around a star that is less bright than our Sun. An interesting coincidence, however, is that Gliese 832c receives just about the same average flux from its parent star as does the Earth. Since the planet was discovered only by a slight wobble in its parent star's motion, the above illustration is just an artistic guess of the planet's appearance -- much remains unknown about Gliese 832c's true mass, size, and atmosphere. If Gliese 832c has an atmosphere like Earth, it may be a super-Earth undergoing strong seasons but capable of supporting life. Alternatively, if Gliese 832c has a thick atmosphere like Venus, it may be a super-Venus and so unlikely to support life as we know it. The close 16-light year distance makes the Gliese 832 planetary system currently the nearest to Earth that could potentially support life. The proximity of the Gliese 832 system therefore lends itself to more detailed future examination and, in the most spectacularly optimistic scenario, actual communication -- were intelligent life found there. July 8, 2014  Why would a cloud appear to be different colors? A relatively rare phenomenon known as iridescent clouds can show unusual colors vividly or a whole spectrum of colors simultaneously. These clouds are formed of small water droplets of nearly uniform size. When the Sun is in the right position and mostly hidden by thick clouds, these thinner clouds significantly diffract sunlight in a nearly coherent manner, with different colors being deflected by different amounts. Therefore, different colors will come to the observer from slightly different directions. Many clouds start with uniform regions that could show iridescence but quickly become too thick, too mixed, or too far from the Sun to exhibit striking colors. The above iridescent cloud was photographed in 2009 from the Himalayan Mountains in Nepal, behind the 6,600-meter peak named Thamserku. July 7, 2014  Most galaxies contain one supermassive black hole -- why does this galaxy have three? The likely reason is that galaxy J1502+1115 is the product of the recent coalescence of three smaller galaxies. The two closest black holes are shown above resolved in radio waves by large coordinated array of antennas spread out over Europe, Asia, and Africa. These two supermassive black holes imaged are separated by about 500 light years and each has a likely mass about 100 million times the mass of our Sun. Currently, J1502+1115, at a redshift of 0.39, is one of only a few triple black hole system known and is being studied to learn more about galaxy and supermassive black hole interaction rates during the middle ages of our universe. Gravitational radiation emitted by such massive black hole systems may be detectable by future observatories. July 6, 2014  This coming Saturday, if it is clear, well placed New Yorkers can go outside at sunset and watch their city act like a modern version of Stonehenge. Manhattan's streets will flood dramatically with sunlight just as the Sun sets precisely at each street's western end. Usually, the tall buildings that line the gridded streets of New York City's tallest borough will hide the setting Sun. This effect makes Manhattan a type of modern Stonehenge, although only aligned to about 30 degrees east of north. Were Manhattan's road grid perfectly aligned to east and west, today's effect would occur on the Vernal and Autumnal Equinox, March 21 and September 21, the only two days that the Sun rises and sets due east and west. Pictured above in this horizontally stretched image, the Sun sets down 34th Street as viewed from Park Avenue. If Saturday's sunset is hidden by clouds do not despair -- the same thing happens twice each year: in late May and mid July. On none of these occasions, however, should you ever look directly at the Sun. July 5, 2014  The spiral arms of bright, active galaxy M106 sprawl through this remarkable multiwavelength portrait, composed of image data from radio to X-rays, across the electromagnetic spectrum. Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici. The well-measured distance to M106 is 23.5 million light-years, making this cosmic scene about 60,000 light-years across. Typical in grand spiral galaxies, dark dust lanes, youthful star clusters, and star forming regions trace spiral arms that converge on a bright nucleus. But this composite highlights two anomalous arms in radio (purple) and X-ray (blue) that seem to arise in the central region of M106, evidence of energetic jets of material blasting into the galaxy's disk. The jets are likely powered by matter falling into a massive central black hole. July 4, 2014   In this alluring time exposure, star trails arc across the night sky above foggy Monterey Bay and the lights of Santa Cruz, California in the United States of America. Since the exposure began around 2:56am PDT on July 2 it also records the trail of a Delta II rocket lofting NASA's OCO-2 spacecraft into orbit. Seen from a vantage point 200 miles north of the Vandenberg Air Force Base launch site, the trail represents the first five minutes of the rocket's flight along a trajectory south and west over the Pacific to join the A-Train in polar orbit around planet Earth. The entire trail through main engine cut-off is captured, with a very faint puff at the end marking the nose fairing separation. Under the rocket's path, the two brightest trails are the alpha and beta stars of the constellation Grus, flying high in southern skies. The OCO-2 mission goal is a study of atmospheric carbon dioxide, watching from space as planet Earth breathes. July 3, 2014  The prominent ridge of emission featured in this vivid skyscape is known as the Cygnus Wall. Part of a larger emission nebula with a distinctive shape popularly called The North America Nebula, the ridge spans about 10 light-years along an outline that suggests the western coast of Mexico. Constructed from narrowband image data, the cosmic close-up maps emission from sulfur, hydrogen, and oxygen atoms to red, green, and blue colors. The result highlights the bright ionization front with fine details of dark, dusty forms in silhouette. Sculpted by energetic radiation from the region's young, hot, massive stars, the dark shapes inhabiting the view are clouds of cool gas and dust with stars likely forming within. The North America Nebula itself, NGC 7000, is about 1,500 light-years away. To find it, look northeast of bright star Deneb in the high flying constellation Cygnus. July 2, 2014  Spiral galaxy NGC 4651 is a mere 62 million light-years distant, toward the well-groomed northern constellation Coma Berenices. About the size of our Milky Way, this island universe is seen to have a faint umbrella-shaped structure that seems to extend (left) some 100 thousand light-years beyond the bright galactic disk. The giant cosmic umbrella is now known to be composed of tidal star streams - extensive trails of stars gravitationally stripped from a smaller satellite galaxy. The small galaxy was eventually torn apart in repeated encounters as it swept back and forth on eccentric orbits through NGC 4651. In fact, the picture insert zooms in on the smaller galaxy's remnant core, identified in an extensive exploration of the system, using data from the large Subaru and Keck telescopes on Mauna Kea. Work begun by a remarkable collaboration of amateur and professional astronomers to image faint structures around bright galaxies suggests that even in nearby galaxies, tidal star streams are common markers of such galactic mergers. The result is explained by models of galaxy formation that also apply to our own Milky Way. July 1, 2014  Some stars explode in slow motion. Rare, massive Wolf-Rayet stars are so tumultuous and hot that they slowly disintegrate right before our telescopes. Glowing gas globs each typically over 30 times more massive than the Earth are being expelled by violent stellar winds. Wolf-Rayet star WR 124, visible near the above image center spanning six light years across, is thus creating the surrounding nebula known as M1-67. Details of why this star has been slowly blowing itself apart over the past 20,000 years remains a topic of research. WR 124 lies 15,000 light-years away towards the constellation of Sagitta. The fate of any given Wolf-Rayet star likely depends on how massive it is, but many are thought to end their lives with spectacular explosions such as supernovas or gamma-ray bursts. June 30, 2014  What's happened to the center of this galaxy? Unusual and dramatic dust lanes run across the center of elliptical galaxy Centaurus A. These dust lanes are so thick they almost completely obscure the galaxy's center in visible light. This is particularly unusual as Cen A's red stars and round shape are characteristic of a giant elliptical galaxy, a galaxy type usually low in dark dust. Cen A, also known as NGC 5128, is also unusual compared to an average elliptical galaxy because it contains a higher proportion of young blue stars and is a very strong source of radio emission. Evidence indicates that Cen A is likely the result of the collision of two normal galaxies. During the collision, many young stars were formed, but details of the creation of Cen A's unusual dust belts are still being researched. Cen A lies only 13 million light years away, making it the closest active galaxy. Cen A, pictured above, spans 60,000 light years and can be seen with binoculars toward the constellation of Centaurus. June 29, 2014  To see a vista like this takes patience, hiking, and a camera. Patience was needed in searching out just the right place and waiting for just the right time. A short hike was needed to reach this rugged perch above a secluded cove in Julia Pfeiffer Burns State Park in California, USA. And a camera was needed for the long exposure required to bring out the faint light from stars and nebulae in the background Milky Way galaxy. Moonlight illuminated the hidden beach and inlet behind nearby trees in the above composite image taken last month. Usually obscured McWay Falls is visible just below the image center, while the Pacific Ocean is in view to its right. June 28, 2014  Orion's belt runs just along the horizon, seen through Earth's atmosphere and rising in this starry snapshot from low Earth orbit on board the International Space Station. The belt stars, Alnitak, Alnilam, and Mintaka run right to left and Orion's sword, home to the great Orion Nebula, hangs above his belt, an orientation unfamiliar to denizens of the planet's northern hemisphere. That puts bright star Rigel, at the foot of Orion, still higher above Orion's belt. Of course the brightest celestial beacon in the frame is Sirius, alpha star of the constellation Canis Major. The station's Destiny Laboratory module is in the foreground at the top right. June 27, 2014  June 24th marked the first full Martian year of the Curiosity Rover's exploration of the surface of the Red Planet. That's 687 Earth days or 669 sols since its landing on August 5, 2012. To celebrate, consider this self-portrait of the car-sized robot posing next to a rocky outcrop dubbed Windjana, its recent drilling and sampling site. The mosaicked selfie was constructed with frames taken this April and May using the rover's Mars Hand Lens Imager (MAHLI), intended for close-up work and mounted at the end of the rover's robotic arm. The MAHLI frames used exclude sections that show the arm itself and so MAHLI and the robotic arm are not seen. Famous for panoramic views, the rover's Mastcam is visible though, on top of the tall mast staring toward the left and down at the drill hole. June 26, 2014  Early morning risers were treated to a beautiful conjunction of Venus and waning Crescent Moon on June 24, captured in this seaside photo near Belmar, New Jersey, USA, planet Earth. The serene celestial pairing is seen above the Atlantic Ocean horizon as the eastern sky grows brighter with dawn's early light. Wispy, scattered clouds appear in silhouette. But the exposure also reveals the night side of the lunar orb in the arms of the sunlit crescent. That shadowed part of the Moon, with hints of the smooth, dark lunar seas or maria, is illuminated by Earthshine, sunlight reflected from planet Earth itself. June 25, 2014  These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars. The colors in this remarkably deep composite image clearly show the star forming galaxies with a blue tint and galaxies with older stellar populations with a yellowish cast. The sharp picture spans about 3/4 degree across the cluster center, corresponding to over 6 million light-years at the cluster's estimated distance. Diffraction spikes around brighter foreground stars in our own Milky Way galaxy are produced by the imaging telescope's mirror support vanes. In the cosmic vista many galaxies seem to be colliding or merging while others seem distorted - clear evidence that cluster galaxies commonly interact. In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe. June 24, 2014  What flowers in this field of dark star dust? The Iris Nebula. The striking blue color of the Iris Nebula is created by light from the bright star SAO 19158 reflecting off of a dense patch of normally dark dust. Not only is the star itself mostly blue, but blue light from the star is preferentially reflected by the dust -- the same affect that makes Earth's sky blue. The brown tint of the pervasive dust comes partly from photoluminescence -- dust converting ultraviolet radiation to red light. Cataloged as NGC 7023, the Iris Nebula is studied frequently because of the unusual prevalence there of Polycyclic Aromatic Hydrocarbons (PAHs), complex molecules that are also released on Earth during the incomplete combustion of wood fires. The bright blue portion of the Iris Nebula spans about six light years. The Iris Nebula, pictured above, lies about 1300 light years distant and can be found with a small telescope toward the constellation of Cepheus. June 23, 2014  Are lasers from giant telescopes being used to attack the Galactic center? No. Lasers shot from telescopes are now commonly used to help increase the accuracy of astronomical observations. In some sky locations, Earth atmosphere-induced fluctuations in starlight can indicate how the air mass over a telescope is changing, but many times no bright star exists in the direction where atmospheric information is needed. In these cases, astronomers create an artificial star where they need it -- with a laser. Subsequent observations of the artificial laser guide star can reveal information so detailed about the blurring effects of the Earth's atmosphere that much of this blurring can be removed by rapidly flexing the mirror. Such adaptive optic techniques allow high-resolution ground-based observations of real stars, planets, and nebulae. Pictured above, four telescopes on Mauna Kea, Hawaii, USA are being used simultaneously to study the center of our Galaxy and so all use a laser to create an artificial star nearby. June 22, 2014  Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraft monitored Saturn's South Pole simultaneously as Cassini closed in on the gas giant in January 2004. Hubble snapped images in ultraviolet light, while Cassini recorded radio emissions and monitored the solar wind. Like on Earth, Saturn's auroras make total or partial rings around magnetic poles. Unlike on Earth, however, Saturn's auroras persist for days, as opposed to only minutes on Earth. Although surely created by charged particles entering the atmosphere, Saturn's auroras also appear to be more closely modulated by the solar wind than either Earth's or Jupiter's auroras. The above sequence shows three Hubble images of Saturn each taken two days apart. June 21, 2014  The Sun set on Friday the 13th as a full Honey Moon rose, captured in this well-planned time-lapse sequence. Lisbon, Portugal's Christ the King monument is in the foreground, about 6 kilometers distant from camera and telephoto lens. During the days surrounding today's solstice (June 21, 10:51 UT) the Sun follows its highest arc through northern hemisphere skies as it travels along the ecliptic plane. At night the ecliptic plane is low, and the Full Moon's path close to the ecliptic was also low, the rising Moon separating more slowly from the distant horizon. Northern moon watchers were likely to experience the mysterious Moon Illusion, the lunar orb appearing impossibly large while near the horizon. But the photo sequence shows the Moon's apparent size did not not change at all. Its light was initially scattered by the long line-of-sight through the atmosphere though, and a deeper reddened color gave way to a paler gold as the Full Moon rose into the night. June 20, 2014  In this night skyscape setting stars trail above the western horizon over Rio de Janeiro, Brazil, a venue for the 2014 World Cup. Gentle arcs from the bright, colorful stars of Orion are near the center of the frame, while the starfield itself straddles planet Earth's celestial equator during the long exposure. Of course, trails from more local lights seem to create the strident paths through the scene. Air traffic smears an intense glow over an airport at the far right, while helicopters fly above the city and boats cruise near the coast. Striping the waterfront are tantalizing reflections of bright lights along the Copacabana and Ipanema beaches. Near the horizon, the brightest fixed light is the famous Cristo statue overlooking Rio at night. June 19, 2014  The central bulge of our Milky Way Galaxy rises above a sea of clouds in this ethereal scene. An echo of the Milky Way's dark dust lanes, the volcanic peak in foreground silhouette is on France's Réunion Island in the southern Indian Ocean. Taken in February, the photograph was voted the winner of the 2014 International Earth and Sky Photo Contest's Beauty of the Night Sky Category. This and other winning and noteable images from the contest were selected from over a thousand entries from 55 countries around planet Earth. Also featured in the contest compilation video (vimeo), the moving images are a testament to the importance and beauty of our world at night. June 18, 2014  Nebulas are perhaps as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. Still, no known cat could have created the vast Cat's Paw Nebula visible in Scorpius. At 5,500 light years distant, Cat's Paw is an emission nebula with a red color that originates from an abundance of ionized hydrogen atoms. Alternatively known as the Bear Claw Nebula or NGC 6334, stars nearly ten times the mass of our Sun have been born there in only the past few million years. Pictured above is a deep field image of the Cat's Paw nebula. June 17, 2014 What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon suddenly became one of the brightest stars in the entire Milky Way Galaxy. Then, just a few months later, it faded. A stellar flash like this has never been seen before -- supernovas and novas expel a tremendous amount of matter out into space. Although the V838 Mon flash appeared to expel some material into space, what is seen in the above eight-frame movie, interpolated for smoothness, is actually an outwardly moving light echo of the flash. The actual time-span of the above movie is from 2002, when the flash was first recorded, to 2006. In a light echo, light from the flash is reflected by successively more distant ellipsoids in the complex array of ambient interstellar dust that already surrounded the star. Currently, the leading model for V838's outburst was the orbital decay and subsequent merging of two relatively normal stars. V838 Mon lies about 20,000 light years away toward the constellation of Monoceros, while the largest light echo above spans about six light years in diameter. June 16, 2014  NASA's APOD turns 19 today. APOD's thank yous: The first APOD appeared 19 years ago today. To help celebrate, APOD brings you today an all-sky heatmap of (nearly) 19 years of APOD entries. The brighter a region appears on the above heatmap, the more APODs that occur in that region. Clicking anywhere on the map will bring up a link to all APODs, if any, that appear nearby. We at APOD again thank our readers, NASA, astrophotographers, volunteers who translate APOD daily into over 20 languages, volunteers who run APOD's over 20 mirror sites, volunteers who answer questions and administer APOD's main discussion board, and volunteers who run and update APOD's social media sites and smartphone applications for their continued support. June 15, 2014  Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group of Galaxies. The Local Group falls toward the Virgo Cluster of Galaxies. But these speeds are less than the speed that all of these objects together move relative to the cosmic microwave background radiation (CMBR). In the above all-sky map from the COBE satellite, radiation in the Earth's direction of motion appears blueshifted and hence hotter, while radiation on the opposite side of the sky is redshifted and colder. The map indicates that the Local Group moves at about 600 kilometers per second relative to this primordial radiation. This high speed was initially unexpected and its magnitude is still unexplained. June 14, 2014  Bright stars of Sagittarius and the center of our Milky Way Galaxy lie just off the wing of a Boeing 747 in this astronomical travel photo. The stratospheric scene was captured earlier this month during a flight from New York to London, 11,000 meters above the Atlantic Ocean. Of course the sky was clear and dark at that altitude, ideal conditions for astronomical imaging. But there were challenges to overcome while looking out a passenger window of the aircraft moving at nearly 1,000 kilometers per hour (600 mph). Over 90 exposures of 30 seconds or less were attempted with a fast lens and sensitive camera setting, using a small, flexible tripod and a blanket to block reflections of interior lighting. In the end, one 10 second long exposure resulted in this steady and colorful example of airborne astronomy. June 13, 2014  June's Full Moon (full phase on June 13, 0411 UT) is traditionally known as the Strawberry Moon or Rose Moon. Of course those names might also describe the appearance of this Full Moon, rising last month over the small Swedish village of Marieby. The Moon looks large in the image because the scene was captured with a long focal length lens from a place about 8 kilometers from the foreground houses. But just by eye a Full Moon rising, even on Friday the 13th, will appear to loom impossibly large near the horizon. That effect has long been recognized as the Moon Illusion. Unlike the magnification provided by a telescope or telephoto lens, the cause of the Moon illusion is still poorly understood and not explained by atmospheric optical effects, such as scattering and refraction, that produce the Moon's blushing color and ragged edge also seen in the photograph. June 12, 2014  The Tarantula Nebula is more than 1,000 light-years in diameter, a giant star forming region within our neighboring galaxy the Large Magellanic Cloud (LMC). That cosmic arachnid lies toward the upper left in this deep and colorful telescopic view made through broad-band and narrow-band filters. The image spans nearly 2 degrees (4 full moons) on the sky and covers a part of the LMC over 8,000 light-years across. Within the Tarantula (NGC 2070), intense radiation, stellar winds and supernova shocks from the central young cluster of massive stars, cataloged as R136, energize the nebular glow and shape the spidery filaments. Around the Tarantula are other violent star-forming regions with young star clusters, filaments, and bubble-shaped clouds In fact, the frame includes the site of the closest supernova in modern times, SN 1987A, just above center. The rich field of view is located in the southern constellation Dorado. June 11, 2014  No, radio dishes cannot broadcast galaxies. Although they can detect them, the above image features a photogenic superposition during a dark night in New Zealand about two weeks ago. As pictured above, the central part of our Milky Way Galaxy is seen rising to the east on the image left and arching high overhead. Beneath the Galactic arc and just above the horizon are the two brightest satellite galaxies of our Milky Way, with the Small Magellanic Cloud to the left and the Large Magellanic Cloud on the right. The radio dish is the Warkworth Satellite Station located just north of Auckland. June 10, 2014   What if we X-rayed an entire spiral galaxy? This was done (again) recently by NASA's Chandra X-ray Observatory for the nearby interacting galaxies known as the Whirlpool (M51). Hundreds of glittering x-ray stars are present in the above Chandra image of the spiral and its neighbor. The image is a conglomerate of X-ray light from Chandra and visible light from the Hubble Space Telescope. The number of luminous x-ray sources, likely neutron star and black hole binary systems within the confines of M51, is unusually high for normal spiral or elliptical galaxies and suggests this cosmic whirlpool has experienced intense bursts of massive star formation. The bright cores of both galaxies, NGC 5194 and NGC 5195 (right and left respectively), also exhibit high-energy activity. In this false-color image where X-rays are depicted in purple, diffuse X-ray emission typically results from multi-million degree gas heated by supernova explosions. June 9, 2014  What is that light in the sky? Perhaps one of humanity's more common questions, an answer may result from a few quick observations. For example -- is it moving or blinking? If so, and if you live near a city, the answer is typically an airplane, since planes are so numerous and so few stars and satellites are bright enough to be seen over the din of artificial city lights. If not, and if you live far from a city, that bright light is likely a planet such as Venus or Mars -- the former of which is constrained to appear near the horizon just before dawn or after dusk. Sometimes the low apparent motion of a distant airplane near the horizon makes it hard to tell from a bright planet, but even this can usually be discerned by the plane's motion over a few minutes. Still unsure? The above chart gives a sometimes-humorous but mostly-accurate assessment. June 8, 2014  Jewels don't shine this bright -- only stars do. Like gems in a jewel box, though, the stars of open cluster NGC 290 glitter in a beautiful display of brightness and color. The photogenic cluster, pictured above, was captured recently by the orbiting Hubble Space Telescope. Open clusters of stars are younger, contain few stars, and contain a much higher fraction of blue stars than do globular clusters of stars. NGC 290 lies about 200,000 light-years distant in a neighboring galaxy called the Small Cloud of Magellan (SMC). The open cluster contains hundreds of stars and spans about 65 light years across. NGC 290 and other open clusters are good laboratories for studying how stars of different masses evolve, since all the open cluster's stars were born at about the same time. June 7, 2014  A star cluster around 2 million years young, M16 is surrounded by natal clouds of dust and glowing gas also known as The Eagle Nebula. This beautifully detailed image of the region includes cosmic sculptures made famous in Hubble Space Telescope close-ups of the starforming complex. Described as elephant trunks or Pillars of Creation, dense, dusty columns rising near the center are light-years in length but are gravitationally contracting to form stars. Energetic radiation from the cluster stars erodes material near the tips, eventually exposing the embedded new stars. Extending from the left edge of the frame is another dusty starforming column known as the Fairy of Eagle Nebula. M16 and the Eagle Nebula lie about 7,000 light-years away, an easy target for binoculars or small telescopes in a nebula rich part of the sky toward the split constellation Serpens Cauda (the tail of the snake). June 6, 2014  Sweeping slowly through northern skies, the comet PanSTARRS C/2012 K1 posed for this telescopic portrait on June 2nd in the constellation Ursa Major. Now in the inner solar system, the icy body from the Oort cloud sports two tails, a lighter broad dust tail and crooked ion tail extending below and right. The comet's condensed greenish coma makes a nice contrast with the spiky yellowish background star above. NGC 3319 appears at the upper left of the frame that spans almost twice the apparent diameter of the full Moon. The spiral galaxy is about 47 million light-years away, far beyond the stars in our own Milky Way. In comparison, the comet was a mere 14 light-minutes from our fair planet. This comet PanSTARRS will slowly grow brighter in the coming months remaining a good target for telescopic comet watchers and reaching perihelion, its closest approach to the Sun, while just beyond Earth's orbit in late August. June 5, 2014  Galaxies like colorful pieces of candy fill the Hubble Ultra Deep Field 2014. The dimmest galaxies are more than 10 billion times fainter than stars visible to the unaided eye and represent the Universe in the extreme past, a few 100 million years after the Big Bang. The image itself was made with the significant addition of ultraviolet data to the Hubble Ultra Deep Field, an update of Hubble's famous most distant gaze toward the southern constellation of Fornax. It now covers the entire range of wavelengths available to Hubble's cameras, from ultraviolet through visible to near-infrared. Ultraviolet data adds the crucial capability of studying star formation in the Hubble Ultra Deep Field galaxies between 5 and 10 billion light-years distant. June 4, 2014  Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just as the setting Sun disappears completely from view, a last glimmer appears startlingly green. The effect is typically visible only from locations with a low, distant horizon, and lasts just a few seconds. A green flash is also visible for a rising Sun, but takes better timing to spot. A dramatic green flash, as well as an even more rare red flash, was caught in the above photograph recently observed during a sunset visible from the Observatorio del Roque de Los Muchachos in the Canary Islands, Spain. The Sun itself does not turn partly green or red -- the effect is caused by layers of the Earth's atmosphere acting like a prism. June 3, 2014  Might this giant pinwheel one-day destroy us? Probably not, but investigation of the unusual star system Wolf-Rayet 104 has turned up an unexpected threat. The unusual pinwheel pattern has been found to be created by energetic winds of gas and dust that are expelled and intertwine as two massive stars orbit each other. One system component is a Wolf-Rayet star, a tumultuous orb in the last stage of evolution before it explodes in a supernova -- and event possible anytime in the next million years. Research into the spiral pattern of the emitted dust, however, indicates the we are looking nearly straight down the spin axis of the system -- possibly the same axis along which a powerful jet would emerge were the supernova accompanied by a gamma-ray burst. Now the WR 104 supernova itself will likely be an impressive but harmless spectacle. Conversely, were Earth really near the center of the powerful GRB beam, even the explosion's 8,000 light year distance might not be far enough to protect us. Currently, neither WR 104 nor GRB beams are understood well enough to know the real level of danger. June 2, 2014  The space station has caught a dragon. Specifically, in mid-April, the International Space Station captured the unmanned SpaceX Dragon capsule sent to resupply the orbiting outpost. Pictured above, the station's Canadarm2 had just grabbed the commercial spaceship. The Dragon capsule was filled with over 5000 lbs (2260 kilos) of supplies and experiments to be used by the current band of six ISS astronauts who compose Expedition 39, as well as the six astronauts who compose Expedition 40. After docking with the ISS, the Dragon capsule was unloaded and eventually released, splashing down in the Pacific Ocean on May 18. The current Expedition 40 crew, now complete, will apply themselves to many tasks including the deployment of the Napor-mini RSA experiment which will use phased array radar and a small optical telescope to monitor possible emergency situations on the Earth below. June 1, 2014  The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years across, which surrounds the brighter, familiar planetary nebula. Made with data from the Nordic Optical Telescope in the Canary Islands, the composite picture shows extended emission from the nebula. Planetary nebulae have long been appreciated as a final phase in the life of a sun-like star. Only much more recently however, have some planetaries been found to have halos like this one, likely formed of material shrugged off during earlier active episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50,000 to 90,000 years. Older archived posts may be found Here. September 1, 2012 - February 28, 2013 March 1, 2013 - July 31, 2013 August 1, 2013 - December 31, 2013 January 1, 2014 - May 31, 2014 This thread will be updated before nightfall Eastern Standard Time Daily. I will try to update when I wake up if I can, to accommodate for users in Europe & Asia. |
Re: Terry's Astronomy Thread.
I feel like i'm sitting in Astronomy class all over again. ;D Will be interesting to see how this progresses (:
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Re: Terry's Astronomy Thread.
It's... Beautiful @_@
I like where this thread is going... I'm in spaaaaaace |
Re: Terry's Astronomy Thread.
Wow Terry shitty thread you have the worst ideas.
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Re: Terry's Astronomy Thread.
Sweet, you got around to make this thread :)
I'd recommend for people Stellarium, it's a really nice tool for alot of stuff if oyu're interested in astronomy, you can set its location to were you are and simulate the sky where you live, and even go back and forth in time etc http://www.stellarium.org/ |
Re: Terry's Astronomy Thread.
Quote:
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Re: Terry's Astronomy Thread.
Naice job haha. Here's a moon phases calandar
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Re: Terry's Astronomy Thread.
I have added the two links to the OP.
What's in the sky tonight? March 11, 2012 -As the moon wanes, a perfectly clear sky and an area that is not light polluted unlocks the chance to track Comet Garradd. Garradd has been visible since January, as it slowly makes it's way across the inner solar system, and will be visible until April. It is currently on its way to pass the Big Dipper, and today it wedges itself nicely between the big dipper and the little dipper. Use This Comet Tracker Guide to help you discover the comet! It's coming in at a magnitude 6.5 though, so you will need a telescope to find it. Under a light polluted city, humans cannot see fainter than magnitude 4-5. (I can see M42 which is Magnitude 4.0 from where I live at the beach of Toronto, but I cannot see it in the heart of Toronto. Location in a city makes a big difference too!) Astro Picture of the Day: March 11, 2012  Source: Comet Garradd within 1 degree of M92, a globular cluster found in Hercules. It approaches the best time for viewing this month. |
Re: Terry's Astronomy Thread.
New link added:
http://www.heavens-above.com/ - Use this website to track the space station, other satellites, when you can see them pass over! The website also tracks comets, planets, and shows a picture of the orbits of the planets. What's in the sky tonight? March 12, 2012 -Jupiter and Venus are just 3.1 degrees apart today in the west. They are at their closest tomorrow where they appear exactly 3.0 degrees away from each other. Today however, they appear exactly level with each other.  -After locating Jupiter and Venus, at around 8:00pm EST turn 170 degrees at the same level to your left. You will see a red dot, this is Mars calmly rising in the East. Mars is at its highest around 1 in the morning. It appears 13.8 arcseconds wide in a telescope, the largest it will appear until 2014. Astro Picture of the Day: March 12, 2012  Source: Ever wonder what the night sky would look like if you took a 4 hour long exopsure with your camera? You'd notice the stars generate neat star trails of how they've progressed over the course of 4 hours. They revolve around the north and south poles in this 360 degree panorama taken in Mudgee, New South Wales, Austrailia. Note* This picture has been adjusted to not stretch the forums. If you want to see the full picture go here Terry's photo of Jupiter-Venus pair last night (conveniently hovering over the Toronto cityscape): |
Re: Terry's Astronomy Thread.
Star trails picture
is completely awesome 0_0 Thanks for sharing this stuff with us, I'll be sure to check this thread every time I log in. |
Re: Terry's Astronomy Thread.
Great thread! I'll be sure to check it out often I'm sure I'll learn some things
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Re: Terry's Astronomy Thread.
NEW FEATURE ADDED: International Space Station Tracker. Updates whenever you refresh.
What's in the Sky Tonight? March 13, 2012 -Jupiter and Venus are at their closest point together for the next few years today, 3 degrees apart. That's about the distance of 3 middle fingers side by side at arms length. -Comet Garradd (At magnitude 6.5) is the brightest and longet lasting comet the northern hemisphere has had in recent memory. It will spend the next two or so days crossing Kappa Draconis in the constellation Draco. Unless you live out of the city, it may be worthless looking for the comet, as light pollution erodes all but the best of it. Use this chart to find the comet as it makes its way towards the Big Dipper. Astro Picture of the Day:  Source: Under a completely dark sky in the southern hemisphere, if you went outside and tilted your head up while the sky was clear, this is what you would see after letting your eyes adjust for about 20 minutes to the faint lights the Milky Way galaxy has to offer. This picture specifically was taken on Mangaia, the southernmost of the Cook islands. The bright stars just off centre to the right are part of the constellation Centaurus. The brightest star is alpha centauri, which follows how stars are typically named. They are named from brightest to dimmest, beginning with the greek alphabet, and often extending into our alphabet. For example, "beta sagittae" is the 2nd brightest star in the constellation Sagittarius. |
Re: Terry's Astronomy Thread.
astounding pics o.o
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Re: Terry's Astronomy Thread.
Quote:
**** you light polution. every night i look up at the sky and im so saddened by the lack of stars it really brings me down, so depressing. |
Re: Terry's Astronomy Thread.
March 14, 2012
-The moon reaches its last quarter phase tonight at exactly 9:25pm EST. It quietly rises in the middle of the night, and it's just above the teapot of Saggitarius at dawn.  Source: This is a digitally stacked series of Mars to track the movement of Mars between October and June. Between this time, Mars appears to move backwards. Approximately every 2 years, Earth passes Mars as they orbit around the Sun. During the pass, Mars appears brightest, and also looks to move backwards in the sky. This is called retrograde motion. At the centre of this loop that Mars makes, retrograde motion is at its highest. |
Re: Terry's Astronomy Thread.
TERRY
this is dope as hell. youre awesome <3 ^_________^ ima look here again tomorrowww!! |
Re: Terry's Astronomy Thread.
What's in the Sky Tonight?
March 15, 2012 -Those in the mid northern latitudes of North America get a special treat this time of year; this is the greatest time of year to see the bulk of the milky way in the evening. Look east-southeast of of Canis Major in the constellation Puppis. A telescope will serve you well here. Astro Picture of the Day March 14, 2012  Source: The heart and soul nebulae are located in Cassiopeia, a familiar constellation in North America due to it's 5 obvious bright stars that are often said to look like a W (or M in this picture). The nebulae shine brightly with the red light of energized hydrogen. There are several young star clusters visible in this image as well, appearing in blue, which makes this area a hot spot for astrophotography. Andromeda Galaxy isn't too far away from this picture either. A hydrogen filter on a camera would bring out the nebulae nicely if one wished to take a picture of these emission nebulae. |
Re: Terry's Astronomy Thread.
What's in the Sky Tonight?
March 16, 2012 -Jupiter and Venus have separated to 4.0 degrees now. Still notably close, but nothing compared to the 13th. -Comet Garradd at 7th magnitude passes within 1/4 of a degree of 4th magnitude star Lambda Draconis. One of the best nights to try and discover this comet! Good luck on your quest to photograph or observe it. Astro Picture of the Day March 16, 2012  Source: One of the most famous images related to space as of late, this is a photo of the Pillars of Creation taken in 1995 by the Hubble Telescope. The pillars lie in the Eagle Nebula dubbed M16 and are associated with an open star cluster. The "pillars" are molecular hydrogen gas and dark dust that doesn't emit light. The pillars are light years in length and so dense that interior gas actually gravitationally contracts to form stars. Unfortunately, this pretty structure is short lived, as there is evidence of a supernova explosion that happened 6,000 years ago. The Eagle Nebula and the Pillars of Creation are about 7,000 light years away, so we only have another thousand years to observe these pillars before we witness their destruction. |
Re: Terry's Astronomy Thread.
Happy St Patrick's Day everyone :D
What's in the Sky Tonight? March 17, 2012 -Have you heard of the Winter Triangle? It contains 3 of some of the brightest stars in the night sky for the northern hemisphere, and it's an equilateral triangle! The brightest of the 3 stars is Sirius, which is found in Canis Major. It is the blue looking star in the southwest. To it's upper right is the red star Betelgeuse, found on the shoulder of Orion. To the left is Procyon found in Canis Minor. All 3 are bright enough to be seen anywhere, no matter how light polluted you are. Did you know Procyon is expected to expand and turn into a red giant at any time? We could witness it happen tomorrow, or 10,000 years from now. Astro Picture of the Day March 17, 2012  Source: This photo is part of the spiral galaxy M83, which is 12 million light years away. It can be found near the bottom of constellation Hydra, and this galaxy is known for it's prominent blue star clusters and red star clusters found in its arms. These clusters have given M83 the nickname of "The Thousand-Ruby Galaxy," but it is more often referred to as the Southern Pinwheel. The centre of this galaxy is dominated by red, older stars so it appears yellow. The blue and red clusters are areas of starbirth, where the blue stars are hot, young, bright and brilliant, and the red clusters are filled with ionized hydrogen, creating new stars. |
Re: Terry's Astronomy Thread.
Terry because of you I'm taking astronomy as my general elective next year. Thanks for peaking an interest :D
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Re: Terry's Astronomy Thread.
Quote:
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Re: Terry's Astronomy Thread.
What's in the Sky Tonight?
March 18, 2012 -Mars is that bright orange strucutre found in Leo, on the opposite side of the sky from the Jupiter-Venus combo. It is 7 degrees from the fainter star, Regulus. Mars is beginning to fade a bit as Earth pulls ahead of Mars in their respective orbits around the sun. Use the solar system orbit chart to help visualize this. Astro Picture of the Day March 18, 2012  Source: Meet the Perseus-Pisces supercluster of galaxies. Spanning more than 40 degrees across the northern winter sky, it is one of the largest known structures in the universe. It ranges from the Perseus constellation to the Pisces constellation, which can't be viewed at at this time because that is the constellation that the sun is currently in. Perseus however, is quite visible after sunset. There are 141 galaxies found in this structure, and is roughly 250 million light years away. When looking through a telescope, each one of these galaxies may appear as a fuzzy blob. This image view covers about 15 million light years across the supercluster. --- What's in the Sky Tonight Archive March 10, 2012 - August 31, 2012 August 31, 2012 -Full Moon (exact at 9:58 a.m. EDT). This is a "blue Moon," when the term means the second full Moon in a calendar month. Blue Moons come every 2.7 years on average. The next is in July 2015. -This week, right after dark is the time when the Big Dipper descends to the same height in the northwest as Cassiopeia rises in the northeast. After this, it'll officially be Cassiopeia season.  August 30, 2012 -Full Moon tonight and tomorrow night (exactly full at 9:58 a.m. EDT tomorrow morning). The Moon tonight is in dim Aquarius. -As sunrise approaches Friday morning, bring binoculars or a wide-field telescope to a spot with a view of the east-northeast horizon to try for the difficult conjunction of Mercury with Regulus, illustrated here. August 29, 2012 -Fomalhaut, the "Autumn Star," rises in the southeast in mid- to late evening; the time depends on your location. Watch for Fomalhaut coming into view below or lower left of the Moon. August 28, 2012 -As twilight fades, spot Arcturus high in the west. Look far to its lower left for Saturn, Spica below it, and Mars to Saturn's left. This triangle is lengthening each evening Saturn and Spica move to the lower right. August 27, 2012 -This is the time of year when the Big Dipper, swinging down in the northwest in evening, catches water dumping from the bowl of the dim Little Dipper high above it. Much of the Little Dipper is made of 4th- and 5th-magnitude stars and requires a fairly dark sky. August 26, 2012 -The Moon shines above the Sagittarius Teapot in the south after dark. -Mercury (about magnitude –1.2) remains in view at dawn but lower each day. It's above the east-northeast horizon, far lower left of brilliant Venus. Look about 45 minutes before sunrise, the earlier in the week the better. August 25, 2012 -The Moon at nightfall shines about equidistant from Antares to its lower right and the Teapot of Sagittarius pouring to its left. -This evening — before the Moon becomes too bright for the rest of the week — you can still use binoculars to try for the Lagoon and Swan nebulae, M8 and M7, above the Sagittarius Teapot as shown here. To the naked eye, the Teapot is roughly the size of your fist at arm's length.  August 24, 2012 -First-quarter Moon this evening. Look for Antares to its lower left. The other stars of upper Scorpius are scattered around them. August 23, 2012 -By about 9 or 10 p.m. (depending on how far east or west you live in your time zone), the Big Dipper sinks in the northwest to the same height that Cassiopeia rises in the northeast. August 22, 2012 -Look for the Saturn-Spica-Mars triangle to the right or lower right of the Moon in twilight, as shown above. -And to the Moon's upper left, look for 3rd-magnitude Alpha (α) Librae. It's a fine, very wide double star for binoculars. You'll find its two components lined up about horizontally.  August 21, 2012 -In twilight the waxing crescent Moon makes a lovely quadrilateral with Saturn, Spica, and Mars low in the southwest, as shown above. They all just fit in a 6° binocular view. By coincidence, this is also the evening when Saturn, Spica, and Mars form an equilateral triangle. August 20, 2012 -Venus (magnitude –4.4, in Gemini) rises in deep darkness around 3 a.m. daylight saving time (depending on where you are), emerging above the east-northeast horizon like a UFO a good two hours before the first glimmer of dawn. By early dawn it's blazing high in the east — vastly outshining Pollux and Castor to its left and Procyon to its lower right. -Uranus (magnitude 5.8, at the Pisces-Cetus border) and Neptune (magnitude 7.8, in Aquarius) reach good heights in the southeast by late evening. August 19, 2012 -Nine Messier objects float within just a couple binocular fields above the lid star of the Sagittarius Teapot, now at its highest in the south in early evening. How many can you detect in my photos, or on your own? Some are easy in binoculars, some are tougher and require a dark sky. -Jupiter (magnitude –2.2, in Taurus) rises in the east-northeast around midnight or 1 a.m. daylight saving time. Once it's well clear of the horizon, look for fainter orange Aldebaran twinkling 5° or 6° to its right or lower right. By dawn Jupiter shines very high in the southeast, about 30° upper right of even brighter Venus. August 18, 2012 -In these waning weeks of summer, autumn's Great Square of Pegasus is already looming up in the east after dark. It's somewhat larger than your fist at arm's length, and is balancing on one corner. -Mars, Saturn, and Spica (in Virgo, very similar at magnitudes 1.1, 0.8, and 1.0 respectively) form a changing triangle low in the west-southwest at dusk, as shown above. Look for them far lower left of Arcturus. Saturn and Spica are moving to the lower right away from Mars, lengthening the triangle day by day. August 17, 2012 -It's already that time of year. If you're up before the first light of dawn, you'll get a preview of wintry Orion coming up in the east-southeast. It's to the right of brilliant Venus, which is in the feet of Gemini near the top of Orion's dim club. -At the bend of the Dipper's handle, you'll know to look for little Alcor shining directly above Mizar. That's because the line from Mizar through Alcor always points to Vega, and Vega is now near the zenith (as seen from mid-northern latitudes). -Mercury is having a good apparition low in the dawn. About 45 minutes to an hour before sunrise, look for it above the east-northeast horizon far lower left of brilliant Venus. Mercury is still brightening, from magnitude –0.4 on the morning of August 18th to –1.0 by the 25th. Though by then it's a little lower. August 16, 2012 -It's already that time of year. If you're up before the first light of dawn, you'll get a preview of wintry Orion coming up in the east-southeast. It's to the right of brilliant Venus, which is in the feet of Gemini near the top of Orion's dim club. -Venus and Jupiter (magnitudes –4.5 and –2.2) shine dramatically in the east before and during dawn. They've widened to about 24° apart, with Jupiter high to Venus's upper right. They're in Gemini and Taurus, respectively. Look for orange Aldebaran, much fainter, 5° right or lower right of Jupiter. Near Aldebaran are the Hyades, and above are the Pleiades.  August 15, 2012 -Vega passes high overhead after dark for skywatchers at mid-northern latitudes (exactly overhead at latitude 39°). Altair is the brightest star high in the southeast, marking the bright eye of Aquila, the Eagle. -Running down the main axis of Aquila are bunches of dark nebulae, two planetary nebulae, and a globular cluster that await hunting with your telescope. August 14, 2012 -No less than nine Messier objects float within just a couple binocular fields of view above the lid star of the Sagittarius Teapot (now at its highest in the south in early evening). How many of these can you detect? Some are easy in binoculars, some are tougher and require a dark sky. August 13, 2012 -Mars is finally passing between Saturn and Spica low in the west-southwestern twilight this evening and tomorrow evening. to pinpoint exactly when Venus will mysteriously vanish and re-appear out of nowhere in your location! This is something you do not want to miss if you have clear skies.Daytime occultation of Venus. This afternoon, telescope users across most of North America can watch the edge of the thin waning crescent Moon cover half-lit Venus in a blue sky. The event happens low for Easterners; the farther west you are, the higher the Moon and Venus will be in your sky. Finding them is the trick. If you live in the area that's within the highlighted portion of the map below, then you can see this happen yourself! Use the list found on the occultation website   August 12, 2012 -Venus hangs below the waning crescent Moon before and during dawn Monday morning, as shown below. -Mars, Saturn, and Spica (very similar at magnitudes 1.1, 0.8, and 1.0 respectively) are bunched low in the west-southwest at dusk, far below bright Arcturus. They form a triangle 4½° tall that changes every day. Mars passes between Saturn and Spica on Monday and Tuesday, August 13th and 14th — turning the triangle into a slightly curved, nearly vertical line.  August 11, 2012 -The Perseid meteor shower should be at its best late tonight. Find a dark spot with a wide-open view of the sky overhead, bundle up against the late-night chill, lie back in a lounge chair, watch the sky, and be patient. After 11 or midnight you may see a meteor a minute on average; fewer earlier. -The thick waning crescent Moon rises by 1 or 2 a.m. (with Jupiter above it). But its modest light, notes the International Meteor Organization, "should be considered more of a nuisance than a deterrent." -You're also likely to see occasional Perseids for many nights before and after. Click here for more information about the Perseids. August 10, 2012 -The waning Moon forms a tight triangle with Jupiter and fainter Aldebaran after they rise about 1 or 2 a.m. Saturday morning. Bright Venus rises far to their lower left around 3 a.m. (depending on where you live). -Have any plans for the weekend? The Perseids peak on Saturday night at approximately midnight EST. August 9, 2012 -Last-quarter Moon (exact at 2:55 p.m. EDT). The lopsided-looking Moon rises around midnight with the Pleiades to its left. -Mars is about to cross Saturn in Spica after sundown in the coming days. It has moved much closer now to form a tight triangle. -Have any plans for the weekend? The Perseids peak on Saturday.  August 8, 2012 -The two brightest stars of summer are Vega, nearly overhead after dark (for skywatchers at mid-northern latitudes), and Arcturus in the west. Look a third of the way from Arcturus to Vega for the dim semicircle of Corona Borealis, the Northern Crown. Look two thirds of the way for the dim Keystone of Hercules, about the same size. August 7, 2012-Have any plans for the weekend? The Perseids peak on Saturday. -The waning gibbous Moon rises in the east as twilight fades away. Look well to the Moon's left or upper left for the Great Square of Pegasus, balancing on one corner. August 6, 2012 -By mid-evening this week, W-shaped Cassiopeia rises as high in the north-northeast as the bowl of the Big Dipper has sunk in the north-northwest. August 5, 2012 -Vega is near the zenith soon after nightfall (as seen from mid-northern latitudes), and this tells you that the rich Milky Way in Sagittarius and the tail of Scorpius is now at its best low in the south. The region is loaded with telescopic star clusters and nebulae. Catch it while you can. -Mars and Saturn (magnitudes +1.1 and +0.8, respectively) are low in the west-southwest at dusk, forming a triangle with similarly bright (but twinklier) Spica. Saturn and Spica are 4½° apart, with Saturn on top. Mars, to Spica's right, is approaching closer to them every day. It will pass between them on August 13th and 14th.  August 4, 2012 -The waning gibbous Moon rises in the east as twilight fades away. Look well to the Moon's left or upper left for the Great Square of Pegasus, balancing on one corner. August 3, 2012 -As summer enters its second half, the Summer Triangle approaches its greatest height in the evening. Face east and look almost straight up after nightfall. The brightest star there is Vega. Toward the northeast from Vega (by two or three fist-widths at arm's length) is Deneb. Toward the southeast from Vega by a greater distance is Altair. August 2, 2012 -Arcturus is the brightest star in the west after dark at this time of year. It and Vega, almost overhead, are the two leading stars of summer. Look off to the right of Arcturus, in the northwest, to spot the Big Dipper dipping down. August 1, 2012 -Full Moon tonight (exact at 11:27 p.m. EDT). The Moon is in dim Capricornus. Shining high above it is Altair. -Venus and Jupiter (magnitudes –4.6 and –2.2) shine dramatically in the east before and during dawn, as shown at right. They've widened to about 14° apart now, with Jupiter higher. Look for Aldebaran, much fainter, lower right of Jupiter. Also near Jupiter are the Hyades, and higher above are the Pleiades.  July 31, 2012 -During early dawn Wednesday and Thursday mornings, look low in the east to spot brilliant Venus, magnitude –4.6. Look 2° upper left of it (roughly a finger's width at arm's length) for Zeta Tauri, magnitude 3.0. That's a brightness difference of just over 1,000 times! Binoculars will be necessary as dawn brightens. -All week, watch Mars move in on Saturn and Spica at dusk.  July 30, 2012 -The waxing gibbous Moon this evening hangs over the handle of the Sagittarius Teapot. -Uranus (magnitude 5.8, at the Pisces-Cetus border) and Neptune (magnitude 7.8, in Aquarius) are high in the southern sky before the first light of dawn. July 29, 2012 -Before and during dawn Monday morning, Jupiter is closest to Aldebaran. They're 4.7° apart, with Aldebaran to Jupiter's lower right. -Mars and Saturn (magnitudes +1.1 and +0.8, respectively) are low in the west-southwest at dusk. Saturn stands 4½° above similarly-bright Spica. Mars is approaching closer to them every day and will pass between them on August 13th and 14th. July 28, 2012 -Fiery Antares shines lower right of the waxing gibbous Moon tonight. -Venus and Jupiter (magnitudes –4.6 and –2.2) shine dramatically in the east before and during dawn, as shown at right. They've widened to about 14° apart now, with Jupiter higher. Look for Aldebaran, much fainter, lower right of Jupiter. Also near Jupiter are the Hyades, and higher above are the Pleiades. The asteroids Ceres and Vesta, magnitudes 9.1 and 8.4, are in the area too! July 27, 2012 -Look left of the Moon (by a fist-width at arm's length or more) for orange Antares. Much closer left of the Moon are the three fainter stars that mark the head of Scorpius, lined up about vertically. -Mars has crept to within 11° of Saturn and Spica, on its way to passing between them in mid-August. -Before or during dawn Saturday morning, telescope users near North America's West Coast can see Jupiter's satellites Io and Europa both casting their tiny black shadows onto Jupiter's face from 4:45 to 5:33 a.m. Pacific Daylight Time. July 26, 2012 -By 10 or 11 p.m. the Great Square of Pegasus is up in the east, balancing on one corner — an early warning of the inevitable approach of fall. -Saturn (magnitude +0.8, in Virgo) shines in the southwest as the stars come out. Below it by 4½° is Spica, nearly the same brightness but twinklier. After dark they move lower to the west-southwest. July 25, 2012 -The first-quarter Moon is left of Spica and Saturn this evening, as shown here. -Uranus (magnitude 5.8, at the Pisces-Cetus border) and Neptune (magnitude 7.8, in Aquarius) are high in the southern sky before the first light of dawn.  July 24, 2012 -The waxing Moon this evening forms a quadrangle with Saturn, Spica, and Mars. -Mars (magnitude +1.0, in Virgo) glows orange low in the west-southwest at dusk, lower right of the Saturn-and-Spica pair by about 13°. It's heading their way; Mars will pass between Saturn and Spica in mid-August. In a telescope Mars is gibbous and very tiny, 6 arcseconds wide. July 23, 2012 -As twilight behind to fade, use the Moon in the west-southwest to guide your way to Saturn, Spica, and Mars glimmering through the dusk (in that order of visibility) as shown below. -Saturn (magnitude +0.8, in Virgo) shines in the southwest as the stars come out. Below it by 4½° is Spica, nearly the same brightness but twinklier. After dark they move lower to the west-southwest. July 22, 2012 -Arcturus is the brightest star high in the west after dark at this time of year. It and Vega, almost overhead, are the two leading stars of summer. Look off to the right of Arcturus, in the northwest, to spot the Big Dipper. -Venus and Jupiter (magnitudes –4.6 and –2.1) shine dramatically in the east before and during dawn. They've widened to about 10° or 12° apart now, with Jupiter higher. Look for Aldebaran, much fainter, below or lower right of Jupiter. Also in Jupiter's starry background are the Hyades, and above it are the Pleiades. July 21, 2012 -Draco the Dragon arches his back over the Little Dipper in the north at this time of year. With your scope, here you can search out the Cat's Eye Nebula, some interesting double stars and galaxies, and (if your scope is big enough) a quasar with a look-back time of 8.6 billion years! July 20, 2012 -The Teapot of Sagittarius is in the south-southeast at nightfall and highest in the south later in the evening. Hidden in the star fields above it is the magnitude-9.5 asteroid 18 Melpomene, which you can ferret out with a telescope. -Just before Sunrise, the first glimpses of the constellation Orion are slowly becoming visible to mid northern latitudes again.  July 19, 2012 -This is the time of year when the Big Dipper, in the northwest after dark, begins scooping down to the right as if preparing to scoop up water. And the dim Little Dipper, standing upright from the North Star at the end of its handle, begins to tip left starting its six-month downward fall. -Uranus (magnitude 5.8, at the Pisces-Cetus border) and Neptune (magnitude 7.8, in Aquarius) are high in the southeast and south before the first light of dawn. July 18, 2012 -Once you've found Vega and Arcturus (see yesterday), imagine a line between them. A third of the way along it from Vega is the dim Keystone of Hercules. Two thirds of the way is the little semicircle constellation Corona Borealis, the dim Northern Crown, with one modestly bright star, Alphecca or Gemma. -Mars (magnitude +1.0, in Virgo) glows orange in the west-southwest at dusk. It's lower right of the Saturn-and-Spica pair, by about 16°. Mars is heading their way; it will pass right between them in mid-August. In a telescope Mars is gibbous and very tiny, only 6 arcseconds wide. July 17, 2012 -The two brightest stars of summer are Vega, very high in the east as the stars come out, and Arcturus, very high in the southwest. Compare their colors. Vega is icy white with a hint of blue; Arcturus is pale yellow-orange. They're both relatively nearby as stars go. It's 25 light-years to Vega, 37 to Arcturus. -Venus and Jupiter (magnitudes –4.7 and –2.1) shine dramatically in the east before and during dawn. They're stacked about 8° apart now, with Jupiter on top. Look for Aldebaran, much fainter, moving away from Venus to its upper right. Also in Venus's starry background are the Hyades, and above Jupiter are the Pleiades. The asteroids Ceres and Vesta, magnitudes 9.1 and 8.4, are there too! July 16, 2012 -July is Scorpius month — at least in the evening hours. Scorpius is highest in the south right at nightfall this week. Its brightest star is orange-red Antares, "Anti-Ares," the "rival of Mars" in Greek. Compare its color with the real Mars moving lower in the west-southwest (to the lower right of the Saturn-and-Spica pair). -Mars (magnitude +1.0, in Virgo) glows orange in the west-southwest at dusk. It's lower right of the Saturn-and-Spica pair, by about 16°. Mars is heading their way; it will pass right between them in mid-August. In a telescope Mars is gibbous and very tiny, only 6 arcseconds wide.  July 15, 2012 -Stars twinkle and planets (being extended objects) don't, right? That's what everyone is supposed to learn when they take up skywatching. But how true is it really? See for yourself by comparing Spica and Saturn as they sink together in the southwest these evenings. Saturn is the one on top. Sometimes the difference is dramatic, other times not so much, depending on the small heat waves rippling in the lower atmosphere. July 14, 2012 -During dawn Sunday morning, the waning crescent poses dramatically with Jupiter and Venus, as shown here for North America. Think photo opportunity! -The Moon actually occults Jupiter for most of Europe and parts of Asia. Jupiter disappears behind the Moon's sunlit limb. A map and timetable can be found on this link for those who will be able to see the occultation: http://www.lunar-occultations.com/io...715jupiter.htm July 13, 2012 -During dawn on Saturday morning, the waning crescent Moon in the east poses to the upper right of Jupiter and lower right of the Pleiades. -Mercury is lost in the sunset. July 12, 2012 -By 11 p.m. daylight time the Great Square of Pegasus, signature constellation of autumn, is already up in the east and balancing on one corner. -Venus and Jupiter (magnitudes –4.7 and –2.1) shine dramatically in the east-northeast before and during dawn. They remain stacked 5° or 6° apart this week, with Jupiter on top. Watch Aldebaran, much fainter, moving this week from below Venus to its right. Also in Venus's starry background are the Hyades, and above Jupiter are the Pleiades. The asteroids Ceres and Vesta, magnitudes 9.1 and 8.4, are there too! July 11, 2012 -Altair is the brightest star halfway up the southeastern sky (halfway from the horizon to the zenith). Look to its left by slightly more than a fist-width, and perhaps a bit lower, for the distinctive little constellation Delphinus, the leaping Dolphin. Its nose points left. -The sunspot continues to be visible, but the chance of the northern lights hitting your region is now waning. July 10, 2012 -As the stars begin to come out, look very high in the east for bright Vega. How soon can you spot the other two stars of the Summer Triangle? Deneb is 24° to Vega's lower left: two or three fist-widths at arm's length. Altair is 34° to Vega's lower right: three or four fists. -Vega passes the zenith around midnight. -The Sun is displaying a spot group big enough to see without optical aid, just a safe solar filter. Active Region AR 1520 is on the eastern side of the Sun as of Monday and is rotating toward the midline of the Sun's face, where it should be all the more obvious — and could blast some serious solar weather our way if a big flare happens to erupt within it. High-res near-real-time image from SOHO.  July 9, 2012 -At nightfall, spot bright Arcturus very high in the southwest to west. It's way above Saturn, Spica, and Mars. Look off to the right of Arcturus for the Big Dipper — which is hanging down and, as night grows late, previewing its late-summer dip as if scooping water. July 8, 2012 -After nightfall at this time of year, the W-shaped constellation Cassiopeia has just passed its lowest point in the north and is beginning its long, slow climb in the north-northeast. The later in the night you look, the more altitude it gains. But the farther south you live, the lower it will be. -Mercury is disappearing deep in the sunset. July 7, 2012 -The red long-period variable star R Draconis should be at its maximum brightness of about magnitude 7.6 this week. Binoculars should show it. -Aldebaran passes 1° to the right or lower right of Venus low in the dawn Sunday through Tuesday mornings.  The dawn sky on July 4th, as captured by Gregg Alliss near Marion, Iowa. He took this 7-second exposure through an 18-mm f/7.1 lens at ISO 800. July 6, 2012 -After nightfall at this time of year, the W-shaped constellation Cassiopeia has just passed its lowest point in the north and is beginning its long, slow climb in the north-northeast. The later in the night you look, the more altitude it gains. But the farther south you live, the lower it will be. -Mercury (about magnitude +0.5 and fading) is becoming harder to see very low in the west-northwest about 45 minutes after sundown. Far to its right are fainter Pollux and Castor; use binoculars. July 5, 2012 -The waning gibbous Moon rises around nightfall. The bright star high above it is Altair. Look a fist-width or more to Altair's left, and perhaps a bit lower, for the little constellation Delphinus, the leaping Dolphin. His nose points left. -Venus and Jupiter (magnitudes –4.7 and –2.1) shine low in the east-northeast during dawn. They're stacked 5° apart with Jupiter on top, as shown at the top of this page. Watch Aldebaran, much fainter, closing in on Venus from below. In Venus's starry background are the Hyades, while the Pleiades pose above Jupiter. Bring binoculars and look early! July 4, 2012 -Watching fireworks this evening? As you're waiting for darkness to arrive, point out the two brightest stars of summer: Vega very high in the east, and Arcturus very high in the southwest. -Far below Arcturus are Saturn and, just under it, Spica. Off to their right and perhaps a bit lower is orangy little Mars. -Earth is at aphelion, its farthest from the Sun for the year (just 1/30 farther than at perihelion in January). July 3, 2012 -The full Moon shines in the southeast after dark. The bright star far to its upper left is Altair. Look just above Altair, by about a finger-width at arm's length, for fainter Tarazed (Gamma Aquilae). Tarazed, an orange giant, is much more luminous than Altair but is almost 20 times farther away (330 light-years, compared to Altair's distance of 17 light-years). -Venus and Jupiter (magnitudes –4.7 and –2.1) shine low in the east-northeast during dawn. They're stacked 5° apart with Jupiter on top, as shown at the top of this page. Watch Aldebaran, much fainter, closing in on Venus from below. In Venus's starry background are the Hyades, while the Pleiades pose above Jupiter. Bring binoculars and look early! July 2, 2012 -Vega is the brightest star very high in the east after dark. Deneb is the brightest to its lower left. Altair is farther to Vega's lower right. These three form the big Summer Triangle. -Mars (magnitude +0.8, in Virgo) glows orange in the west-southwest at dusk and lower in the west later. It's still about 22° from the Saturn-and-Spica pair to its left, but it's heading their way. Mars will pass right between them in mid-August. In a telescope Mars is gibbous and very tiny (6.6 arcseconds wide), continuing to fade and shrink. July 1, 2012 -As soon as the stars come out, look high in the northwest for the Big Dipper hanging straight down by its handle. As night advances, the Dipper dips lower and to the right as if to scoop up water. -In the early morning hours about 1 hour before sunrise, look for Aldebaran of the Hyades, Venus in the Hyades, Jupiter, and the Pleiades to be in a near vertical line, rising higher in the sky as dawn brightens.  June 30, 2012 -The Moon shines in the head stars of Scorpius this evening, with Antares to its lower left. -Remember when Venus and Jupiter paired up spectacularly in the evening last March? Now they're at it again, but this time low in the dawn, as shown at right. Best time: about an hour or so before your local sunrise. -A leap second will be inserted into the world's civil time systems at the end of June 30th Coordinated Universal Time (the second before 8:00 p.m. Eastern Daylight Time). The minute 23:59 UTC will have 61 seconds, not 60, to adjust for a slight accumulated slowdown in Earth's spin. The last leap second was added to the world's clocks at the end of 2008. As the moment arrives, watch your favourite online time service and see if they get it right. June 29, 2012 -Now that June is about to turn into July, the Teapot of Sagittarius is up and sitting level low in the southeast after the sky becomes fully dark -Venus, Jupiter, and the Pleiades make a vertical line in the morning dawn today.  June 28, 2012 -Saturn and Spica are now to the right of the waxing gibbous Moon. -Have you spotted Jupiter and Venus low in the dawn yet? They're getting higher and easier every day. June 27, 2012 -The Moon forms a nice triangle with Saturn and Spica this evening, as shown here. -This is the Latest sunset of the year (at 40° north latitude) even though the solstice and longest day were on June 20th.  June 26, 2012 -First-quarter Moon this evening (exact at 11:30 p.m. EDT). The Moon shines in Virgo, below the line from Saturn to Mars. -Mercury (about magnitude 0.0 and fading) is low in the west-northwest about 40 to 60 minutes after sundown. Well to its right are fainter Pollux and Castor. June 25, 2012 -The Moon shines below distant little Mars during and after dusk. -Mars (magnitude +0.8, in Virgo) shines orange in the southwest at dusk and lower in the west later. It's still about 25° from the Saturn-and-Spica pair to its left, but it's heading their way! Mars will shoot the gap between them in mid-August. June 24, 2012 -The brightest star high in the east these evenings is Vega. The brightest far to its lower right is Altair. Left or lower left of Altair, by a bit more than a fist-width at arm's length, look for the little constellation Delphinus, the leaping Dolphin. Its nose points left. -Venus (magnitude –4.5) shines low in the east-northeast during dawn. Don't confuse it with Jupiter to its upper right. The two planets remain 5° or 6° apart this week, crossing the background of Aldebaran and the Hyades. June 23, 2012 -Look about a fist-width over the Moon for Regulus this evening, as shown above. -Uranus (magnitude 5.9, at the Pisces-Cetus border) is in the east-southeast before the first light of dawn.  June 22, 2012 -Spot the crescent Moon in the western twilight this evening, and look far to its right for Mercury, Pollux, and Castor, as shown above. Binoculars help. -Mercury (about magnitude –0.3 and fading) is very low in the west-northwest about 30 or 40 minutes after sundown. Don't confuse it with Capella far to its right, in the northwest. Pollux and Castor are above Mercury early in the week, and to the right of it by June 23rd. June 21, 2012 -As the glow of sunset fades, look low in the west-northwest for a ragged line of the thin crescent Moon, Mercury, Pollux, and Castor, as shown below. June 20, 2012 -This is the longest day and shortest night of the year in the Northern Hemisphere. Summer begins at the solstice: 7:09 p.m. EDT. This is when the Sun reaches its northernmost point in the sky and begins its six-month return southward. In the Southern Hemisphere, winter begins. -If you have a good view of the west-northwest horizon (from mid-northern latitudes), mark precisely where the Sun sets. In a few days you should be able to detect that it's again starting to set a little south of this point. Build your own Stonehenge? -Mercury (about magnitude –0.3 and fading) is very low in the west-northwest about 30 or 40 minutes after sundown. Don't confuse it with Capella far to its right, in the northwest. Pollux and Castor are above Mercury early in the week, and to the right of it by June 23rd. June 19, 2012 -This is the time of year when the Little Dipper floats straight upward from Polaris after dark — like a released helium balloon. -New Moon (exact at 11:02 a.m. EDT). -Mars (magnitude +0.7, crossing from Leo into Virgo) shines orange in the southwest at dusk and lower in the west as evening grows late. This week Mars creeps to the halfway point from Regulus (off to its lower right) to the Saturn-and-Spica pair (left). Mars will shoot the gap between Saturn and Spica in mid-August. In a telescope Mars is gibbous and tiny, continuing to shrink every week. June 18, 2012 -Vega is the brightest star on the eastern side of the evening sky. Deneb is the brightest to its lower left. Altair is farther to Vega's lower right. These form the big Summer Triangle. June 17, 2012-This season there's another, temporary "Summer Triangle" toward the southwest: bright Arcturus high on top, the Saturn-Spica pair below it, and Mars off to the pair's right or lower right. -Venus (magnitude –4.3), after transiting the Sun on June 5th, is now deep in the glow of dawn. Look for it low in the east-northeast before sunrise. Don't confuse Venus with Jupiter to its upper right. The two planets are 9° apart on the morning of June 16th and 6° apart on June 23rd. -Below or lower right of Venus twinkles much fainter Aldebaran; use binoculars as daybreak brightens. Jupiter and Venus, the two brightest planets, are on their way up for a grand showing in the morning sky this summer. -Can you see the big Coma Berenices star cluster? Does your light pollution really hide it, or do you just not know exactly where to look? The cluster is 2/5 of the way from Denebola (Leo's tail) to the end of the Big Dipper's handle (Ursa Major's tail). The cluster is about 5° wide — a big, dim glow in at least a moderately dark sky. Its brightest members form an inverted Y that nearly fills a binocular view. -Mercury (about magnitude –0.3 and fading) is very low in the west-northwest about 30 or 40 minutes after sundown. Don't confuse it with Capella far to its right, in the northwest. Pollux and Castor are above Mercury early in the week, and to the right of it by June 23rd. June 16, 2012 -If you're awake in early dawn Sunday morning, look low in the east-northeast for the thin waning crescent Moon close to Jupiter, as shown here. As dawn brightens look for Venus 9° to Jupiter's lower left. Bring binoculars.  June 15, 2012 -With summer beginning in just five days, Scorpius is already rearing up in the southeast at nightfall. Its brightest star is orange Antares. The "outrigger" stars of Antares are just below and upper right of it. Farther upper right is the row of stars marking Scorpius's head. This is a grand area to explore with a sky atlas and binoculars. -As dawn brightens Saturday morning, the Moon, Jupiter, and Venus form a diagonal line above where the Sun will rise, as shown here. -If you happen to be in a dark area or are pulling an allnighter outside today, you can expect to see a few meteorites blaze through the sky; the Lyrid meteor shower peaks today. June 14, 2012 -Globular star clusters are not all alike. But some do look more similar than others. With the Moon out of the sky, now is a fine time to compare and contrast many of them in your scope. -Saturn (magnitude +0.6, in Virgo) shines high in the south as twilight fades. Below it by 5° is Spica. Later after dark they move to the southwest. June 13, 2012 -Mercury is becoming more easily visible after sunset. Look for it low in the west-northwest in the fading twilight. It forms a long, vertical triangle with Pollux and Castor above it. -Mercury (about magnitude –0.8) is very low in the west-northwest about 30 or 40 minutes after sundown. Don't confuse it with Capella well to its upper right, in the northwest. June 12, 2012 -Look a third of the way from Arcturus to Vega for the dim semicircle of Corona Borealis, the Northern Crown. It has one modestly bright star, Alphecca. Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules. -Mars (magnitude +0.6) shines orange near the hind foot of Leo, in the southwest at dusk and lower in the west as evening grows late. Mars is still less than halfway from Regulus (off to its lower right) to the Saturn-and-Spica pair (left). Mars will shoot the gap between Saturn and Spica in mid-August. June 11, 2012 -The two brightest stars of late spring and summer are Arcturus, now almost overhead toward the south or southwest after dark, and Vega, shining partway up the eastern sky. Arcturus is an orange giant 37 light-years away. Vega is a hot, white main-sequence star 25 light-years distant. -Venus, having crossed the Sun from east to west during its transit on June 5th, is now very deep in the brightest glow of dawn. Don't confuse Venus with Jupiter, which is less low in the dawn and somewhat to the right. The two planets are 14° apart on the morning of June 9th and 9° apart by June 16th. Use binoculars as daylight brightens; look just above the east-northeast horizon. Jupiter and Venus are on their way up for a grand showing high in the morning sky this summer. June 10, 2012 -After nightfall, Vega is the brightest star shining on the eastern side of the sky. Deneb is the brightest to its lower left. Look for Altair farther to Vega's lower right, still rather low. These three form the big Summer Triangle. -This season there's another, temporary "summer triangle" in the southwest: bright Arcturus high on top, the Saturn-Spica pair below it, and Mars off to the pair's right or lower right. -Last quarter Moon tonight (exact at 6:41 a.m. Monday morning EDT). The Moon, half-lit, rises in Aquarius in the middle of the night. By that time the Summer Triangle is very high in the east, high above it. June 9, 2012 -Binocular observers are often told to recognize a globular cluster as "a fuzzy star." How fuzzy? You can make the comparison very directly between the globular cluster M5 and the star 5 Serpentis just southeast of it. The star is magnitude 5.1; the cluster is 5.7 in total. June 8, 2012 -With June well under way, the Big Dipper has swung around to hang down by its handle high in the northwest during evening. The middle star of its handle is Mizar, with little Alcor right next to it. On which side of Mizar should you look for Alcor? As always, on the side toward bright Vega, which is now shining in the east-northeast. June 7, 2012 -Have you ever explored the swarm of galaxies awaiting your telescope by the head of Serpens? See if you can find out how many Messier objects and objects on the NGC you can find here! -Mars (magnitude +0.5) shines orange near the hind foot of Leo, high in the southwest at dusk and lower in the west as evening grows late. It's now roughly a third of the way from Regulus (off to its lower right) to the Saturn-and-Spica pair (left). Mars is heading east against the stars to pass right between Saturn and Spica in mid-August. June 6, 2012 -Look very high in the south after dark for bright Arcturus. Much lower, and perhaps a bit right, are Saturn and (below it) Spica. Farther down to their lower right is the four-star pattern of Corvus, the Crow. June 5, 2012 -Transit of Venus across the face of the Sun this afternoon for North and Central America; on June 6th local date for Asia, Australia, and much of Europe. Go here to see more details.  You may or may not have heard already that on June 5th, (6th if you are in the eastern side of the world) the planet Venus is going to cross the Sun in a dramatic 6 and a half hour show. The first thing you need to know is are you in the area where it is going to be displayed to the world? Use the following map courtesy of SkyandTelescope to see:  In other words, unless you live in South America, West Africa, Spain or Portugal, or Antarctica, you have a chance to see this event, weather permitting. Their article here puts it best: http://www.skyandtelescope.com/obser...134332798.html However, if you do not wish to click the link, you can also read some of the article in this spoiler. Often we're told about a particular astronomical event — eclipses and planet line-ups, for example — that happen only rarely. But Venus crossing the face of the Sun on June 5–6, 2012, takes "rare" to a new level. Don't miss the chance to see this, because you'll never have another chance in your lifetime. June's celestial spectacle, called a transit of Venus, happens only four times every 243 years. However, the spacing between each occurrence is very uneven: it's 121½ years, then 8 years, then 105½ years, then 8 years again. The last transit occurred in June 2004 — and after this June's event there won't be another until December 2117. Fortunately, unlike the narrow, fleeting path of visibility for a total solar eclipse, the upcoming transit by Venus will last for about 6½ hours and can be seen from more than half of Earth's surface. For most of North America, the transit of Venus will begin on the afternoon of June 5th and still be in progress at sunset. Those in western Pacific, eastern Asia, and eastern Australia see the whole show from beginning to end on June 6th (local date). Click on the image for a larger, worldwide map. Michael Zeiler / Eclipse-maps.com As the map here shows, North Americans are positioned to see at least a portion of it on the afternoon of June 5th. Unfortunately, almost everyone in South America will miss out. On the other side of the globe (click on the map), portions of the transit are observable at or after sunrise on June 6th from Europe, northeast Africa, west and south-central Asia, and western Australia. The best-positioned skygazers are those in eastern Asia, eastern Australia, Alaska, New Zealand, and all of the Pacific from Hawaii westward. They have ringside seats for watching the entire transit, including the crucial events around both its start and finish. People living in the Northern Hemisphere will see a longer show due to the parallax of Venus. The reason for this is illustrated in the following image, where one watching in north america sees Venus cross a lower portion of the sun, than someone in austrailia who sees Venus crossing a higher portion of the sun.  So what time does it all happen? It depends on your location. Here are three tables of major cities where the times of the transit will begin and end. Some definitions: External Ingress: Venus touches the edge of the sun. The Transit starts here. Internal Ingress: Venus completely enters the sun, and appears as a silhouette. Greatest Transit: The deepest point of the transit. Internal Egress: The time of the exact moment Venus begins to depart the sun's image. External Egress: The time of the exact moment Venus leaves the sun's image. The Transit ends here. CANADA: http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Tab02.pdf UNITED STATES: http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Tab03.pdf WORLD: http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Tab04.pdf ---------------------------------------- Now this is likely the last transit of Venus you are going to see in your lifetime, unless you plan to live for another 105 years after this year. Unless you get clouded over, I recommend making an attempt to see this twice in a lifetime (for us) event. Some generations live their full lives without ever seeing what it looks like. To the untrained person, they won't realise what's happening as Venus covers just 3% of the surface of the Sun. Unless they're looking straight at the sun, it will appear to be a normal day. Scientist's can use the transit to calculate precisely the circumference of the Sun, and other characteristics of the sun. The sun is crucial to our understanding of measuring more distant objects, and -everyone- is being invited to participate in a measurement where you can calculate the exact moment Venus exteranlly ingressed and egressed the sun. Read more about this here. http://transitofvenus.nl/wp/getting-...suns-distance/ I am prepared for the Transit, assuming I have good weather. Are you? If you do not have good weather, or you live in an area where there is no transit: You can watch the transit online from -anyone- of the online broadcasts found in this link. Don't let poor weather hamper your experience! http://www.skyandtelescope.com/obser...154213475.html June 4, 2012 -This evening, look for red Antares about 4° lower right of the full Moon (as seen from North America). -Partial eclipse of the Moon before and during dawn Monday morning for central and western North America. The partial eclipse begins at 3:00 a.m. PDT; mid-eclipse (with 38% of the Moon's diameter in shadow) is at 4:03 a.m. PDT; partial eclipse ends at 5:07 a.m. PDT.  June 3, 2012 -Venus is now virtually impossible to see this week as it is hidden in the glare of the sun, that is except for 6 hours and 20 minutes on June 5th when it crosses the path of the sun. -Mercury is beginning to emerge into view low in the sunset. By late this week, look for it low in the west-northwest about 30 minutes after sundown. Don't confuse it with Capella well to its right, in the northwest. June 2, 2012 -The gibbous Moon shines in the south-southeast after dark. Look well to its lower left for orange Antares. Nearly halfway between the Moon and Antares is the row of three stars marking the head of Scorpius. There will also be a partial eclipse of the moon on the 4th of June. June 1, 2012 -By 10 or 11 p.m. (depending on your location) the Summer Triangle is up in the east. Its top corner is Vega: the brightest star in the eastern sky. Deneb is the brightest star to Vega's lower left. Look for Altair substantially farther to Venus's lower right. May 31, 2012 -The gibbous Moon, Spica, and Saturn form an upward line this evening. How straight the line is will depend on when and where you're viewing from. -In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You can see its crescent shape with firmly braced binoculars.   May 30, 2012 -Saturn and Spica are well to the left of the Moon this evening. Less far below the Moon, look for the four-star pattern of Corvus, the Crow, as shown here. May 29, 2012 -Bright Arcturus shines southeast of the zenith after dark. Vega, equally bright, shines less high in the east-northeast. -A third of the way from Arcturus to Vega, look for dim Corona Borealis, the Northern Crown, with its one modestly bright star, Alphecca. Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules. May 28, 2012 -Mars shines above the first-quarter Moon this evening. -Saturn (magnitude +0.5, in Virgo) shines high in the south at nightfall. Below it by nearly 5° is Spica, fainter and bluer. They set in the west before dawn. May 27, 2012 -Look above the Moon this evening for Regulus and, higher and fainter, Gamma Leonis. To the left of these three is Mars. -This week is the last chance to see Venus before the Transit of Venus June 5th. In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You may be able to see its crescent shape in binoculars. Venus is still a blazing magnitude -4.3, but will continue to get fainter as it sinks lower into the glare of the sun. May 26, 2012 -By late evening the summer constellation Scorpius is well up in the south-southeast, as shown at right. Look for its brightest star, fire-colored Antares, the Scorpion's heart. Antares' "outrigger" stars are just below it and to its upper right. Farther upper right is the diagonal three-star row of Scorpius's head, topped by Beta Scorpii. -This week is the last chance to see Venus before the Transit of Venus June 5th. In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You may be able to see its crescent shape in binoculars. May 25, 2012 -Well to the right of the Moon this evening shine Pollux and Castor, the heads of the Gemini twins. They're lined up almost horizontally. Look well below the Moon for Procyon, one of the last remaining stars of the winter triangle in the evening sky. -Venus is now at the peak of its evening drama, dropping faster into the bright sunset every day. How many more days can you follow it with your naked eyes? With binoculars? Don't confuse it with Capella about 20° to its upper right. See our article, Venus Takes the Plunge. In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You may be able to see its crescent shape in binoculars. May 24, 2012 -In a telescope, Venus is a dramatic, thin crescent becoming more interesting all the time. This week it enlarges from 50 to 54 arcseconds tall while waning from 10% to just 4% sunlit. You may even see the crescent with firmly braced binoculars. -This evening Pollux and Castor are lined up above or upper right of the crescent Moon.   May 23, 2012 -Using the Moon and Venus as your guides, what fainter stars in the area can you identify with the chart here? Binoculars help. You will be looking at the stars of Gemini. Pollux and Castor are the 'heads' of the Gemini twins. May 22, 2012 -After sunset, look for the thin two-day-old Moon left of Venus, as shown here. This is the last chance to see the moon and Venus beside each other for an entire year, so if weather permits you, don't miss out. May 21, 2012 -Can you pick up this month's thin crescent Moon yet? During twilight in the Americas it's barely 24 hours old. (After all, it was in front of the Sun yesterday afternoon!) Using binoculars, look for it no more than a half hour after sunset well below Venus in the west-northwest, as shown at lower right. May 20, 2012 -Partial/annular eclipse of the Sun! This afternoon, all but easternmost North America will experience at least a partial eclipse of the Sun. So will the Pacific and (on the morning of May 21st local date) the eastern half of Asia. The eclipse will become annular — with the rim of the Sun a brilliant ring surrounding the dark silhouette of the Moon — along a path from south China and parts of Japan across the Pacific to the California-Oregon coast and from there southeastward to end at sunset in Texas. Go here to read more about the eclipse. Also see the Upcoming Events tab in the main post for more specific information. -Arcturus shines high in the southeastern sky after dark. Vega, equally bright, shines lower in the northeast. A third of the way from Arcturus to Vega, look for dim Corona Borealis, the Northern Crown, with its one modestly bright star, Alphecca. Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules. -New Moon (exact at 7:47 p.m. Eastern Daylight Time). May 19, 2012 -Venus, moving lower in the west every evening as twilight fades, is now 2° left of much fainter Beta Tauri, which has been descending almost in parallel with it. Have you been monitoring the crescent Venus this month? -Partial/annular solar eclipse tomorrow! On Sunday afternoon, all but easternmost North America will experience at least a partial eclipse of the Sun. So will the Pacific and (on the morning of May 21st local date) the eastern half of Asia. The eclipse will become annular — with the rim of the Sun a brilliant ring surrounding the dark silhouette of the Moon — along a path from south China and parts of Japan across the Pacific to the California-Oregon coast and from there southeastward to end at sunset in Texas. If you are not in the path of the Eclipse, you can watch it happen online live here.[U May 18, 2012 -Arcturus is the brightest star high in the southeast these evenings. It's the leading light of the constellation Bootes, the Herdsman. The main stars of Bootes form a narrow, bent kite shape extending left of Arcturus, nearly three fists at arm's length long. Or maybe the kite is a pointy-toed shoe, with Arcturus the tip of the toe. This constellation also holds the Bootes Void, a huge mass of space with almost no galaxies.  May 17, 2012 -The Summer Triangle is fully up in the east by about 11 p.m. Its top star is Vega, the brightest in the eastern sky. About two fist-widths to Vega's lower left is Deneb. Farther to Vega's lower right is Altair. If you have a dark sky, you'll see that the Milky Way runs through it. May 16, 2012 -This is the time of year when the Big Dipper floats upside down at its highest due north when the stars come out. Far below it is Polaris. Far below Polaris, near or even below the horizon depending on your latitude, is W-shaped Cassiopeia. May 15, 2012 -Arcturus shines high in the southeast after dark. Vega, equally bright, shines lower in the northeast. A third of the way from Arcturus to Vega look for dim Corona Borealis, the Northern Crown, with its one modestly bright star, Alphecca. -Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules. May 14, 2012 -The pair of points you'll find shining fairly high in the southeast at nightfall are Saturn and (to its lower right) Spica. Look to their lower right for the four-star pattern of Corvus, the Crow. Look farther to their upper left for brighter Arcturus, the "Spring Star." -Jupiter is in conjunction behind the Sun. May 13, 2012 -Use Venus, the bright landmark point in the west-northwest at dusk, to identify stars in the May twilight. Capella is to Venus's upper right. Pollux and Castor are farther to Venus's upper left, and Procyon is lower left of Pollux. These four stars form the enormous Twilight Arch of Spring. -In a telescope, Venus is a crescent becoming more interesting all the time. It has enlarged to about 46 arcseconds tall while waning to about 15% sunlit; watch it changing daily. You may even see Venus's crescent shape with good, firmly braced binoculars. An arcminute is 1/360th of a degree. An arcsecond is 1/360th of an arcminute. May 12, 2012 -Last-quarter Moon (exact at 5:47 p.m. Eastern Daylight Time). The Moon rises in the middle of the night, looking lopsided and awkward in dim Aquarius. -Keep an eye out for 2 very exciting events coming up. On May 20, we are featured to an annular solar eclipse, and June 5th brings us the Transit of Venus. The annular solar eclipse occurs when the moon is too far away from the Earth to successfully block the whole body of the sun, forming a "ring" of Sun. Hence the name, annular solar eclipse. See here for an example: May 11, 2012 -Brilliant Venus is dropping lower in the west-northwest every evening this month. A telescope shows it enlarging and waning in phase, as shown here; it's swinging ever closer to the line between us and the Sun. Look a little to its right for the much fainter star Beta Tauri. As of tonight the planet and star are 1½° apart. May 10, 2012 -For deep-sky observers, a favorite springtime telescopic star-hop runs from the end of the Big Dipper's handle to the Whirlpool Galaxy, M51, and on to the Sunflower Galaxy, M63. -Venus is now a crescent about 42 arcseconds tall and 20% sunlit, waning and enlarging daily. Venus will transit the face of the Sun on June 5–6 (on the afternoon of the 5th for North America). This is the last transit of Venus until 2117. This will be talked about in great detail as this date approaches. May 9, 2012 -Look for bright Vega moderately low in the northeast after darkness falls, and higher later. To Vega's lower right dangle fainter stars of the little constellation Lyra. -Venus is now a crescent about 42 arcseconds tall and 20% sunlit, waning and enlarging daily. Venus will transit the face of the Sun on June 5–6 (on the afternoon of the 5th for North America). This is the last transit of Venus until 2117. May 8, 2012 -The brightest star very high in the east these evenings is Arcturus. Look three fist-widths to its lower right for Saturn and, a little farther on, Spica. -Mars in a telescope is gibbous and small, about 9.5 arcseconds wide, fading and shrinking each week. Regulus is about 7° Mars's right or lower right and moving farther from it daily. Fainter Gamma Leonis is 8° above Regulus. May 7, 2012 -The waning gibbous Moon is up in the southeast by around 11 p.m., depending on where you live. Look about a fist-width to the Moon's right for fiery Antares. Around and upper right of Antares are other stars of Scorpius. -Jupiter is lost in the glare of the Sun. May 6, 2012 -Venus, the brilliant "Evening Star" in the west, is passing its closest to the star Beta Tauri, which is only 1/300 as bright at magnitude 1.6. During and after late twilight, look for the star 0.8° to Venus's upper right. That's about a pencil-width at arm's length. Although they look close together, they're not. Venus is 3 light-minutes from us; Beta Tauri is 130 light-years in the background. Here is a personal photo of mine of the pair from last night. May 5, 2012 -Full Moon (exact at 11:35 p.m. EDT), in Libra. This is the closest and largest full Moon of 2012, though not remarkably so. The Moon is 8% closer and larger than average, and only 0.16 magnitude brighter than average, so you'd need measuring tools to really tell. Take a look. What do you think?  The moon will rise at 8:16PM in Toronto. It will vary depending where you live. Use this to calculate when it will rise in your location. May 4, 2012 -Look above the bright Moon this evening for Saturn and Spica, as shown here.  May 3, 2012[/center] -Saturn and Spica are left or lower left of the waxing gibbous Moon, as shown here. Look lower right of the Moon for the four-star pattern of Corvus, the Crow.  -The next 35 or so days will bring great drama to how we view the planet Venus, beginning as a "half-Venus" sunlit phase, Venus will sink quickly into the horizon, but not before it becomes a thinner, yet LARGER crescent. All this just before it's June 5th-6th transit of the sun. Read here for more details http://www.skyandtelescope.com/observing/home/Venus-Takes-the-Plunge-149763175.html  May 1, 2012 -The Moon forms the bottom of a big triangle with Mars to its upper right and Denebola, the tail star of Leo, to its upper left. -This is the time of year when the Gemini twins stand upright in the west as darkness arrives. Their head stars, Pollux and Castor, are nearly horizontal (depending on your latitude). Lower left of them shines Procyon. Farther lower right of them is Capella. Stealing the show lower down this year is brilliant Venus. April 30, 2012 -The Moon shines below Mars, Regulus, and Gamma Leonis (Algieba) this evening, as shown here. -Venus is at its "greatest illuminated extent" — showing the most sunlit apparent area (in square arcseconds) that it's going to this apparition.  April 29, 2012 -The Moon shines near the Leo-Cancer border, forming a roughly straight line with, running to its left or upper left: 4th-magnitude Omicron Leonis, 1st-magnitude Regulus, and zero-magnitude Mars. April 28, 2012 -Evenings this week sport three planet-and-star pairs. High in the south, Mars shines with Regulus to its right at dusk, lower right later. Down in the southeast, Saturn shines with Spica to its lower right. Both these pairs are now about 5° wide. -Meanwhile in the west, dazzling Venus is approaching much fainter Beta Tauri (El Nath) above it. Tonight Venus and Beta Tauri are 3.5° apart. By Saturday May 5th their separation is just 0.9°. April 27, 2012 -Look for Pollux and Castor, the not-quite-twin stars of Gemini, upper right of the Moon this evening. Lower left of the Moon shines Procyon. -This evening a 9.7-magnitude star in Virgo will be occulted by the small asteroid 1030 Vitja along a path from the New York City area though the northern Great Lakes. The occultation will happen within a few minutes of 9:57 p.m. EDT and will last for up to 6 seconds. Maps and details. April 26, 2012 -This evening the Moon is in the feet of Gemini, below Pollux and Castor and high above Betelgeuse. -Mars (magnitude –0.2) shines fire-orange in Leo, high in the south at dusk and southwest later in the evening. Regulus is 5° to Mars's right or lower right. Fainter Gamma Leonis is 8° above them. Mars in a telescope is gibbous and small, 10.5 arcseconds wide, fading and shrinking weekly. April 25, 2012 -The Moon shines amid (counting clockwise) Pollux and Castor above it, Auriga with Capella to its right, Venus to its lower right, Aldebaran more or less below it, Orion to its lower left, and Procyon farther to its upper left. -After dusk, three 10th-magnitude asteroids await your probing scope in and around Leo. You will be looking for 5 Astraea, 6 Hebe, and 8 Flora.  April 24, 2012 -Venus is upper right of the crescent Moon this evening. -Look high to Venus's upper right at dusk for Capella, to its lower left for Aldebaran, and farther to its lower right for the Pleiades. Far beneath Venus, Jupiter is sinking into the sunset. April 23, 2012 -Look for the Pleiades to the right of the thin crescent Moon as twilight deepens, as shown here. -With Saturn past opposition, say goodbye to the Seeliger effect, the opposition brightening of Saturn's rings. Here is a comparison image to demonstrate the effect  April 22, 2012 -Jupiter shines below a very thin crescent Moon very low in the west-northwest in twilight, shown below. Think photo opportunity. April 21, 2012 -The weak but unpredictable Lyrid meteor shower should reach maximum activity in the hours before dawn Sunday morning. There will be no Moon. You might see a dozen Lyrids per hour under ideal dark-sky conditions before the beginning of dawn. Find more information about today's meteor shower here. -New Moon (exact at 3:18 a.m. EDT on the 21st). April 20, 2012 -Capella, Venus, and Aldebaran form an almost perfectly straight line in the western sky this evening and Saturday evening, in that order from upper right to lower left. -The best time to examine Venus in a telescope is late afternoon or around sundown. It's now a thick crescent 33 arcseconds tall and 33% sunlit, waning and enlarging week by week as it swings closer to Earth. Venus will transit the face of the Sun on June 5–6 (the afternoon of the 5th for North America). A transit is an eclipse that does not completely cover the object because to us, it appears to small. This is the only Venusian transit you will get to experience. April 19, 2012 -Bright Vega is now visible low in the northeast as early as 9:30 or 10 p.m. (depending on where you live). Bright Arcturus dominates the high sky due east. Look a third of the way from Arcturus to Vega for dim Corona Borealis, the Northern Crown, with its one modestly bright star, Alphecca. Look two-thirds of the way from Arcturus to Vega for the dimmer Keystone of Hercules. -Keep an eye out for the weak but unpredictable meteor shower which will peak saturday night-sunday morning. Read here for more. April 18, 2012 -This is the time of year when the dim Little Dipper juts to the right from Polaris (its handle-end) at nightfall. The much brighter Big Dipper curls over high above it, "dumping water" straight down into it. -Jupiter (magnitude –2.0) is sinking ever lower toward the sunset, far below Venus. It's rounding toward the far side of the Sun, which is why a telescope shows it a disappointingly small 33 arcseconds wide. In addition, Jupiter appears increasingly fuzzy at its ever-lower altitude. April 17, 2012 -The eclipsing variable star Algol is at minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 10:44 p.m. EDT (9:44 p.m. CDT). This is the last chance till August to see Algol at minimum from the latitudes of the U.S. -Mercury (magnitude +0.4) is deep in the glow of sunrise. It's having a very poor dawn apparition just above the eastern horizon. -Keep careful watch on Saturn and its rings in a telescope. With Saturn at or near near opposition, notice the Seeliger effect: a temporary brightening of the rings with respect to the globe. This happens because the solid particles making up the rings backscatter sunlight (reflect it back in the direction it came from) more effectively than the planet's cloudtops do. Compare how the rings and globe look now with with how they look a week or more past opposition. By April 12th, three days before Saturn's opposition, the planet's rings had already brightened quite noticeably due to the Seeliger effect. South is up. A comparison image by the same photographer has been posted below.   April 16, 2012 -As twilight fades, Look for bright Sirius in the southwest, Orion's horizontal Belt off to the right (with Betelgeuse above it, Rigel below it), and Aldebaran and Venus farther to the right in the west. As it sinks ever lower in the west, notice how it starts twinkling more violently, even temporarily changing colours to yellows and reds. Why is this? As it lowers into the horizon, Sirius and other stars have more atmosphere to travel to from your eyes to the location of the star. Because of this, the light of the star is often distorted through the increased atmosphere and can be strong enough to change what colour rays reach your eyes. This is the same reason why the Sun rises reddish in colour, and why the moon also rises in a red-orange colour. It also explains their often distorted and enlarged shape. Take this picture of the sun for example.  -Mercury (magnitude +0.4) is deep in the glow of sunrise. It's having a very poor dawn apparition just above the eastern horizon. -Neptune (magnitude 7.9, in Aquarius) is barely emerging into view low in the east-southeast before dawn's first light. Both of these planets were hidden in the glare of the sun last week. April 15, 2012 -Venus (magnitude –4.6; in Taurus) is shining the highest and brightest it ever appears in the evening sky during its 8-year cycle of repeating apparitions. Venus comes into easy view high in the west soon after sunset. It doesn't set in the northwest until around 11 or even midnight daylight saving time (depending on where you live). You can see Venus through the clear blue sky of day if your eye lands right on it; look for it 44° (4 or 5 fist-widths at arm's length) to the Sun's celestial east-northeast. Look high to Venus's upper right at dusk for Capella, to its lower left for Aldebaran, and to its lower right for the Pleiades. Far below Venus in twilight is Jupiter. The best time to examine Venus in a telescope is late afternoon or around sunset. It's now a thick crescent 30 arcseconds tall and 40% sunlit, waning and enlarging week by week as it swings toward Earth. -Keep careful watch on Saturn and its rings in a telescope. With Saturn at or near near opposition, notice the Seeliger effect: a temporary brightening of the rings with respect to the globe. This happens because the solid particles making up the rings backscatter sunlight (reflect it back in the direction it came from) more effectively than the planet's cloudtops do. Compare how the rings and globe look now with with how they look a week or more past opposition. April 14, 2012 -Saturn is at opposition, opposite the Sun. It rises around sunset, shines highest in the middle of the night, and sets around sunrise. Telescope users: watch for the Seeliger effect, described under Saturn in "This Week's Planet Roundup" below. -Mars ends its retrograde (westward) motion for the year and resumes heading east against the background stars. Watch it pull away from Regulus in the coming weeks: slowly at first, then faster. April 13, 2012 -Summer preview: stay up until 11 and look northeast, and you'll get a preview of bright Vega, the "Summer Star" in little Lyra, climbing into good view. This is an astronomical sign that summer is approaching for North Americans. -Last-quarter Moon (exact at 6:50 a.m. on this date EDT). April 12, 2012 -Near the back leg of Leo is the asteroid 5 Astraea, about magnitude 9.6. Use this preview to track the location of the asteroid. It can be found on page 52. -Toronto residents get the best view of the space station tonight of the month incase you missed the 2 passes last night. The next good pass is well over a week away, so take advantage of the weather. You will be looking for a bright white-yellow ball moving at a high speed (think about the speed of a plane, but only identifyable as a dot) beginning by cutting through Orion, past Gemini, and passing the Big Dipper, before passing Bootes and siappearing into the Corona Borealis constellation. Don't miss out on this one! Pass A: This pass rises above the horizon at 21:00:38, and enters the shadow of the Earth at 21:09:33. The maximum altitude time is 21:05:54, and it will appear 80 degrees high at its peak in the northwest - just 10 degrees shorter than the maximum. Event Time Altitude Azimuth Distance (km) Rises above horizon 21:00:38 -0° 239° (WSW) 2,288 Reaches 10° altitude 21:02:41 10° 241° (WSW) 1,439 Maximum altitude 21:05:54 80° 320° (NW ) 407 Enters shadow 21:09:33 8° 57° (ENE) 1,606 Drops below 10° altitude 21:09:10 10° 56° (ENE) 1,449 Use the following star map to get a feel for the location and how fast the space station travels throughout it's ~6 minute appearance. More details can be found in the link in "Pass A". NOTE: These times are specifically calculated for TORONTO, ON. If you're interested and wish to have a shot at looking at the Space Station, open the "International Space Station Tracker" tab in this thread, and follow the instructions. Good luck, and don't blink! Binoculars are very helpful for picking out detail. April 11, 2012 -With the Moon gone from the evening sky, it's deep-sky observing time again. Telescope users are familiar with the "Leo Trio" of galaxies (M65, M66, and NGC 3628) by the little chair asterism in the back leg of Leo. Can you detect M65 and M66 with binoculars? -Toronto residents should consider the International Space Station Tracker as the Space Station makes very visible passes over the city tonight and an even brighter appearance tomorrow night at a reasonable hour. There will be two passes tonight: Pass A: This pass rises above the horizon at 20:20:54, and enters the shadow of the Earth at 20:30:09. The maximum altitude time is 20:25:52, and it will appear 26 degrees high at its peak. At it's peak it will appear in the Southeast. Event Time Altitude Azimuth Distance (km) Rises above horizon 20:20:54 -0° 209° (SSW) 2,283 Reaches 10° altitude 20:23:09 10° 196° (SSW) 1,435 Maximum altitude 20:25:52 26° 138° (SE ) 818 Enters shadow 20:30:09 3° 69° (ENE) 1,998 Drops below 10° altitude20:28:40 10° 78° (ENE) 1,446 Use the following star map to get a feel for the location and how fast the space station travels throughout it's ~6 minute appearance. More details can be found in the link in "Pass A". Pass B: This is the better of the two passes tonight. At its peak, the space station will be almost 300 km closer to us, and the sun will also have long set. The maximum altitude will be 45 degrees - halfway up the sky. Event Time Altitude Azimuth Distance (km) Rises above horizon 21:56:46 0° 253° (WSW) 2,292 Reaches 10° altitude 21:58:52 10° 260° (W ) 1,442 Maximum altitude 22:02:00 45° 335° (NNW) 553 Enters shadow 22:02:37 39° 10° (N ) 615 Use the following star map to get a feel for the location and how fast the space station travels throughout it's ~6 minute appearance. More details can be found in the link in "Pass B". NOTE: These times are specifically calculated for TORONTO, ON. If you're interested and wish to have a shot at looking at the Space Station, open the "International Space Station Tracker" tab in this thread, and follow the instructions. Good luck, and don't blink! April 10, 2012 -The bright star high to the upper right of Venus these evenings is Capella, the Goat Star. It's the same yellow-white color, and thus the same temperature, as the Sun. The wavelength of the star is a good measurement of indicating how hot a star is. It's also how we know the temperature of our own sun! The shorter the wavelength, the warmer the star. Wavelengths are also used to calculate how fast the star is moving to, or from us by how much it has redshifted (how much the elemental spectra of a star has moved to the longer end of the spectrum compared to the elemental spectra at rest state found here, and as such, is moving away) or blueshifted (how much the elemental spectra of a star has moved to the shorter end of the spectrum compared to the elemental spectra at rest state found here, and as such, is heading towards us). The greater the shift, the faster the object is moving to or from us. -You can see Venus in the clear blue sky of daytime, if your eye lands right on it. The best time to examine Venus in a telescope is late afternoon or around sunset. It's now a thick crescent that has grown to 27 arcseconds tall as it rounds the Sun and approaches Earth. April 9, 2012 -The Big Dipper, high in the northeast, dumps water into the dim Little Dipper during evening at this time of year. -Jupiter is sinking ever lower toward the sunset far below Venus. Jupiter is rounding toward the far side of the Sun, which is why a telescope shows it a disappointingly small 33 arcseconds wide. In addition, Jupiter appears increasingly fuzzy at its ever-lower altitude. April 8, 2012 -As twilight fades down, Look for bright Sirius in the southwest, Orion's horizontal Belt off to the right, and Aldebaran and Venus farther to the right in the west. They all form a long, almost straight line. The line is horizontal if you live near latitude 38° north. -Venus (magnitude –4.6; in Taurus) shines very high and ever more brilliant in the west during and after twilight. It doesn't set now until some 2½ hours after dark. This is just about as high and bright as Venus ever becomes in its 8-year cycle of apparitions. Look to its lower right for the Pleiades, and to its left for orange Aldebaran. April 7, 2012 -The bright Moon rises around the end of twilight below Saturn and Spica in the east-southeast. Later in the evening the three shine higher: a long, narrow triangle with the Moon at the bottom. -Saturn (magnitude +0.2, in Virgo) is at opposition April 15th. This week it rises almost around sunset and stands highest in the south around 1 or 2 a.m. daylight-saving time. Shining 5½° to Saturn's right is Spica: fainter, bluer, and twinklier. -Keep careful watch on Saturn and its rings in a telescope. In the days leading up to opposition, watch for the Seeliger effect: a brightening of the rings with respect to the globe. This happens because the solid particles making up the rings backscatter sunlight (reflect it back in the direction it came from) more effectively than the planet's cloudtops do. April 6, 2012 -Full Moon (exact at 3:19 p.m. EDT). This evening the Moon shines in the east with Spica a little to its left and Saturn farther left — a pretty lineup, as shown here. Farther to the Moon's right, look for the four-star pattern of Corvus, the Crow. Much farther to the upper left (outside the picture here) is bright Arcturus, the "Spring Star." -Mars (magnitude –0.7) shines bright fire-orange under the belly of Leo. Regulus is 5° to Mars's right in the evening, and Gamma Leonis is 7° above it. Mars was at opposition on March 3rd. Now it's fading and shrinking as Earth pulls ahead of it along our faster, inside-track orbit around the Sun. But at least Mars is shining higher in the evening sky now. It's highest in the south by around 10 or 11 p.m. daylight-saving time.  April 5, 2012 -The Moon is nearly full this evening. Look left of it for Gamma (γ) Virginis (Porrima), a tight telescopic double star. (Its separation is 1.8 arcseconds this spring; it's widening year by year). Look farther lower left of the Moon for steady-shining Saturn and twinkly Spica, as shown here. And look to the Moon's lower right for the four-star pattern of the constellation Corvus, the Crow. April 4, 2012 -Two planet-and-star pairings mark the evening sky of spring 2012. After nightfall this week, Mars shines high in the south with Regulus to its right (by 5°). As evening advances, Saturn rises into view low in the east-southeast with Spica to its right (by 5½°). April 3, 2012 -The Moon now forms the bottom point of a narrow triangle with Mars and Regulus, as shown below. -Venus is the closest it will come to the middle of the Pleiades. This evening for the Americas, Venus is passing just ½° southeast of Alcyone (the brightest Pleiad) and ¼° south of the Atlas-Pleione pair. Venus is magnitude –4.5, which means Alcyone, at magnitude 2.85, is 900 times fainter! -Saturn rises with Spica in Virgo late in the evening, clearly visible by midnight.   April 2, 2012 -Venus is passing through the outskirts of the Pleiades this evening through Wednesday evening, as shown below. Binoculars or a wide-field telescope give a fine view of the delicate cluster behind Venus's overpowering glare. -The waxing gibbous Moon forms a slightly curving line with Mars and Regulus, as shown below. April 1, 2012 -The Belt of Orion points left toward Sirius, and right toward Aldebaran and (farther on) brilliant Venus. The winter constellations continue to sink in the west as April rolls in. -Look for Venus to dance with the Pleiades between now and April 5! This is the best chance to understand the Pleiades' location in the sky and how they look like in general. -That V-Shaped cluster with the brilliant red star Alderbaran manning the top of the V is the other popular star cluster, the Hyades. It is much closer to us, and as such spans about 5 degrees of the sky. Aldebaran is actually not part of the cluster however, it's merely a red giant that happens to be in the line of sight between the Earth and the cluster. Previous Month: March 31, 2012 -The Moon shines high in the southwest this evening. It forms a gently curving line (as seen from North America) with Pollux and Castor to its upper right and Procyon below it. Procyon is one of the 3 stars in the Winter Triangle, and as it sets earlier and earlier every day, it's an astronomical sign spring and summer are upon us. March 30, 2012 -First-quarter Moon (exact at 3:41 p.m. EDT). The Moon shines in the legs of Gemini, below Pollux and Castor and high above sinking Betelgeuse. -Saturn is high in the south by 1:00 a.m. near Spica. March 29, 2012 -This is the time of year when the dim Little Dipper juts to the right from Polaris (its handle-end) during evening hours. The much brighter Big Dipper curls over high above it, "dumping water" into it. -This is also the time of year when Orion, declining in the southwest after dark, displays his three-star Belt more or less horizontally. March 28, 2012 -Do you have a pair of binoculars? Are you familiar with them? Today we turn our attention to the constellation of Cancer, where the relatively subtle constellation secretly has a few hidden treasures. The most obvious of them is M44, the Beehive Cluster. M67 is a fainter cluster a little further south of Cancer, and Iota Cancri, in my opinion the toughest of the 3 to distinguish, is a double star of 2 stars with similar brightness. It is difficult because they are two stars, 4th and 6th magnitude, that are very close together from our vantage point and may be difficult to distinguish from. -The eclipsing variable star Algol should be at minimum light, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 9:00 p.m. EDT.  March 27, 2012 -As night comes on, look for the little Pleiades cluster to the lower right of the Moon and above Venus. Left of the Moon shines orange Aldebaran, with the stars of the Hyades around it. -Early Wednesday morning, along a path from New Mexico to central California, the 6.8-magnitude star 14 Virginis will be occulted low in the west-southwestern sky by the small asteroid 823 Sisigambis. The star should vanish for no more than 1.6 seconds within several minutes of 11:23 Universal Time. March 26, 2012 -If you missed yesterday's Jupiter-moon pair, don't worry, there is one more chance tonight. This time, the Moon-Venus pair will dominate the night sky, with the Moon being on the left hand side of the pair. In reality, Venus is 260 times farther away from us than the Moon. Venus is at its greatest elongation, 46 degrees east of the Sun, making this the best time to spot Venus during daylight hours. How early can YOU spot Venus? I have been able to as early as 80 minutes before sunset.   March 25, 2012 -The moon visits Jupiter today in the west this evening. Make sure you get a good look tonight, because you won't see Jupiter and the Moon this close again until April 22, but then there will be a much thinner moon, and an ever fainter Jupiter buried deep in bright twilight. It will be several months before such a pairing is seen after that. Use this chart to find Jupiter before the sun sets!  March 24, 2012 -In order from highest to lowest, Venus, Jupiter, and the thin crescent moon form a bent line in the west and are evenly spread apart tonight. -As darkness deepens, look for the Pleiades (M45) just above Venus. The bent line points to them! March 23, 2012 -Look low in the west about a half hour after sunset, below Venus and Jupiter and perhaps a little right, for the very thin crescent Moon in the bright twilight — as shown at bottom-right here. March 22, 2012 -Our familiar Venus and Jupiter scene in the west has now shifted into a vertical pillar. Venus is 6 degrees directly above Jupiter (there may be slight variance depending on your location.) -New Moon (exact at 10:37 a.m. EDT). March 21, 2012 -The moon is out of the sky long enough to do some serious deep sky hunting. Have you heard of the messier objects? Messier was a comet hunter who generated a list of objects that were -not- comets, and passed this list on to other comet hunters. This list generated 110 objects, and is mostly galaxies, with a fair amount of star clusters. Some nebulae exist too. Refer to here for the complete list of Messier's catalogue. March 20, 2012 -This is the time of year when the dim Little Dipper juts to the right from Polaris (found in the constellation's its handle end) during evening hours. The much brighter Big Dipper curls over high above it, "dumping water" into it. -This is also the time of year when Orion declines in the southwest after dark with his Belt roughly horizontal. But when does Orion's Belt appear exactly horizontal? That depends on where you're located east-west in your time zone, and on your latitude. How accurately can you time this event at your location? Orion's Belt is slightly curved, so judge by the two stars on its ends. Can you rig up a sighting reference to make your measurement more precise? Welcome to pre-telescopic astronomy! March 19, 2012 -Spring begins in the northern hemisphere tonight at 1:14am Tuesday EST, 10:14pm Monday PST when the sun crosses the equator on its way north. Now the sun rises and sets almost due east and west, and day and night are equally long. Autumn begins in the Southern Hemisphere. -In the northern hemisphere, look northwest for the W-shaped constellation Cassiopeia, now standing on its end. March 18, 2012 -Mars is that bright orange strucutre found in Leo, on the opposite side of the sky from the Jupiter-Venus combo. It is 7 degrees from the fainter star, Regulus. Mars is beginning to fade a bit as Earth pulls ahead of Mars in their respective orbits around the sun. Use the solar system orbit chart to help visualize this. March 17, 2012 -Have you heard of the Winter Triangle? It contains 3 of some of the brightest stars in the night sky for the northern hemisphere, and it's an equilateral triangle! The brightest of the 3 stars is Sirius, which is found in Canis Major. It is the blue looking star in the southwest. To it's upper right is the red star Betelgeuse, found on the shoulder of Orion. To the left is Procyon found in Canis Minor. All 3 are bright enough to be seen anywhere, no matter how light polluted you are. Did you know Procyon is expected to expand and turn into a red giant at any time? We could witness it happen tomorrow, or 10,000 years from now. March 16, 2012 -Jupiter and Venus have separated to 4.0 degrees now. Still notably close, but nothing compared to the 13th. -Comet Garradd at 7th magnitude passes within 1/4 of a degree of 4th magnitude star Lambda Draconis. One of the best nights to try and discover this comet! Good luck on your quest to photograph or observe it. March 15, 2012 -Those in the mid northern latitudes of North America get a special treat this time of year; this is the greatest time of year to see the bulk of the milky way in the evening. Look east-southeast of of Canis Major in the constellation Puppis. A telescope will serve you well here. March 14, 2012 -The moon reaches its last quarter phase tonight at exactly 9:25pm EST. It quietly rises in the middle of the night, and it's just above the teapot of Saggitarius at dawn. March 13, 2012 -Jupiter and Venus are at their closest point together for the next few years today. -Comet Garradd (At magnitude 6.5) is the brightest and longet lasting comet the northern hemisphere has had in recent memory. It will spend the next two or so days crossing Kappa Draconis in the constellation Draco. Unless you live out of the city, it may be worthless looking for the comet, as light pollution erodes all but the best of it. Use this chart to find the comet as it makes its way towards the Big Dipper. March 12, 2012 -Jupiter and Venus are just 3.1 degrees apart today in the west. They are at their closest tomorrow where they appear exactly 3.0 degrees away from each other. Today however, they appear exactly level with each other. -After locating Jupiter and Venus, at around 8:00pm EST turn 170 degrees at the same level to your left. You will see a red dot, this is Mars calmly rising in the East. Mars is at its highest around 1 in the morning. It appears 13.8 arcseconds wide in a telescope, the largest it will appear until 2014. March 11, 2012 -As the moon wanes, a perfectly clear sky and an area that is not light polluted unlocks the chance to track Comet Garradd. Garradd has been visible since January, as it slowly makes it's way across the inner solar system, and will be visible until April. It is currently on its way to pass the Big Dipper, and today it wedges itself nicely between the big dipper and the little dipper. Use This Comet Tracker Guide to help you discover the comet! It's coming in at a magnitude 6.5 though, so you will need a telescope to find it. Under a light polluted city, humans cannot see fainter than magnitude 4-5. (I can see M42 which is Magnitude 4.0 from where I live at the beach of Toronto, but I cannot see it in the heart of Toronto. Location in a city makes a big difference too!) March 10, 2012 -The most obvious one if you don't know this already is the Jupiter-Venus conjunction. If you wondered what those two bright 'stars' are in the west, it is Jupiter (the dimmer 'star') and Venus (the brighter 'star'). On March 12, the lower Venus crosses paths with Jupiter and are just 3 degrees apart from each other - close enough to be seen in a single view with binoculars. Great photo opportunity! Weather permitting, these two planets are near impossible to miss, even to those who live in the most polluted of cities. Use SkyandTelescope's picture to help picture what the two should look like over a given day:  -This is a great month to view Saturn, who rises in the east around 10-11pm depending on DST or not, if you have a telescope or even a good pair of binoculars, you will see Saturn's rings are tilted 15 degrees towards us. In a picture it looks like this:  Astro Pic of the Day Archive March 10, 2012 - August 31, 2012 August 31, 2012  The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this tantalizing image, processed to reveal the enormous but extremely faint halo of gaseous material, about 6 light-years across, which surrounds the brighter, familiar planetary nebula. Made with narrow and broadband data the composite picture shows the remarkably strong extended emission from twice ionized oxygen atoms in blue-green hues and ionized hydrogen and nitrogen in red. Planetary nebulae have long been appreciated as a final phase in the life of a sun-like star. But recently many planetaries have been found to have halos like this one, likely formed of material shrugged off during earlier active episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50,000 to 90,000 years. August 30, 2012  As far as pulsars go, PSR B1509-58 appears young. Light from the supernova explosion that gave birth to it would have first reached Earth some 1,700 years ago. The magnetized, 20 kilometer-diameter neutron star spins 7 times per second, a cosmic dynamo that powers a wind of charged particles. The energetic wind creates the surrounding nebula's X-ray glow in this tantalizing image from the Chandra X-ray Observatory. Low energy X-rays are in red, medium energies in green, and high energies in blue. The pulsar itself is in the bright central region. Remarkably, the nebula's tantalizing, complicated structure resembles a hand. PSR B1509-58 is about 17,000 light-years away in the southern constellation Circinus. At that distance the Chandra image spans 100 light-years. August 29, 2012  There is something very unusual in this picture of the Earth - can you find it? A fleeting phenomenon once thought to be only a legend has been newly caught if you know just where to look. The above image was taken from the orbiting International Space Station (ISS) in late April and shows familiar ISS solar panels on the far left and part of a robotic arm to the far right. The rarely imaged phenomenon is known as a red sprite and it can be seen, albeit faintly, just over the bright area on the image right. This bright area and the red sprite are different types of lightning, with the white flash the more typical type. Although sprites have been reported anecdotally for as long as 300 years, they were first caught on film in 1989 - by accident. Much remains unknown about sprites including how they occur, their effect on the atmospheric global electric circuit, and if they are somehow related to other upper atmospheric lightning phenomena such as blue jets or terrestrial gamma flashes. August 28, 2012  Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the lower center. Rho Ophiuchi lies at the center of the blue nebula near the top. The distant globular cluster M4 is visible just to the right of Antares, and to the lower left of the red cloud engulfing Sigma Scorpii. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum. August 27, 2012  Three thousand light-years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the Cat's Eye Nebula to be one of the most complex planetary nebulae known. In fact, the features seen in the Cat's Eye are so complex that astronomers suspect the bright central object may actually be a binary star system. The term planetary nebula, used to describe this general class of objects, is misleading. Although these objects may appear round and planet-like in small telescopes, high resolution images reveal them to be stars surrounded by cocoons of gas blown off in the late stages of stellar evolution. August 26, 2012  A human first set foot on another world on July 20, 1969. This world was Earth's own Moon. In honor of Armstrong's death, today's picture of the day is a digitally restored video of this milestone in human history. Pictured above is Neil Armstrong preparing to take the historic first step. On the way down the Lunar Module ladder, Armstrong released equipment which included the television camera that recorded this fuzzy image. Pictures and voice transmissions were broadcast live to a world wide audience estimated at one fifth of the world's population. The Apollo Moon landings have since been described as the greatest technological achievement the world has known.  On that same July 20, 1969, Apollo 11 astronauts Neil Armstrong and Edwin "Buzz" Aldrin became the first to walk on the Moon. This panorama of their landing site sweeps across the magnificent desolation of the Moon's Sea of Tranquility, with their Lunar Module, the Eagle, in the background at the far left. East Crater, about 30 meters wide and 4 meters deep, is on the right (scroll right), and was so named because it is about 60 meters east of the Lunar Module. Armstrong had piloted the Eagle safely over the crater. Near the end of his stay on the lunar surface Armstrong strayed far enough from the Lunar Module to take the pictures used to construct this wide-angle view, his shadow appearing at the panorama's left edge. The object near the middle foreground is a stereo close-up camera. August 25, 2012  In cosmic brush strokes of glowing hydrogen gas, this beautiful skyscape unfolds across the plane of our Milky Way Galaxy and the center of the northern constellation Cygnus the Swan. Recorded from a premier remote observatory site (ROSA) in southern France, the image spans about 6 degrees. Bright supergiant star Gamma Cygni near image center lies in the foreground of the complex gas and dust clouds and crowded star fields. Left of Gamma Cygni, shaped like two luminous wings divided by a long dark dust lane is IC 1318, whose popular name is understandably the Butterfly Nebula. The more compact, bright nebula at the lower right is NGC 6888, the Crescent Nebula. Some distance estimates for Gamma Cygni place it at around 750 light-years while estimates for IC 1318 and NGC 6888 range from 2,000 to 5,000 light-years. August 24, 2012  Rising in the dark hours before dawn, wandering Venus now shines as the brilliant morning star. Its close conjunction with the Moon on August 13 was appreciated around planet Earth. But skygazers in eastern Asia were also treated to a lunar occultation, the waning crescent Moon passing directly in front of the bright planet in still dark skies. This composite image constructed from frames made at 10 minute intervals follows the celestial performance (vimeo video) from above the city lights and clouds over Taebaek, Korea. The occultation begins near the horizon and progresses as the pair rises. Venus first disappears behind the Moon's sunlit crescent, emerging before dawn from the dark lunar limb. August 23, 2012  During the past week, nightfall on planet Earth has featured Mars, Saturn, and Spica in a lovely conjunction near the western horizon. Still forming the corners of a distinctive celestial triangle after sunset and recently joined by a crescent Moon, they are all about the same brightness but can exhibit different colors to the discerning eye. This ingenious star trail image was recorded as the trio set on August 12 with a telephoto lens from the shores of Lake Eppalock, in central Victoria, Australia. Focused on foreground eucalyptus trees, the image slightly blurs the trails to show more saturated colors. Can you guess which trail is which? Of course the reddest trail is Mars, with Saturn on the right a paler echo of the Red Planet's hue. Left is hot and luminous Spica, bluish alpha star of the constellation Virgo. August 22, 2012  Is that a cloud hovering over the Sun? Yes, but it is quite different than a cloud hovering over the Earth. The long light feature on the left of the above color-inverted image is actually a solar filament and is composed of mostly charged hydrogen gas held aloft by the Sun's looping magnetic field. By contrast, clouds over the Earth are usually much cooler, composed mostly of tiny water droplets, and are held aloft by upward air motions because they are weigh so little. The above filament was captured on the Sun about two weeks ago near the active solar region AR 1535 visible on the right with dark sunspots. Filaments typically last for a few days to a week, but a long filament like this might hover over the Sun's surface for a month or more. Some filaments trigger large Hyder flares if they suddenly collapse back onto the Sun. August 21, 2012   What happens to matter that falls toward an energetic black hole? In the case of Cygnus X-1, perhaps little of that matter actually makes it in. Infalling gas may first collide not only with itself but with an accretion disk of swirling material surrounding the black hole. The result may be a microquasar that glows across the electromagnetic spectrum and produces powerful jets that expel much of the infalling matter back into the cosmos at near light speed before it can even approach the black hole's event horizon. Confirmation that black hole jets may create expanding shells has come recently from the discovery of shells surrounding Cygnus X-1. Pictured above on the upper right is one such shell quite possibly created by the jet of microquasar and black hole candidate Cygnus X-1. Rolling your cursor over the image will bring up an annotated version. The physical processes that create the black hole jets is a topic that continues to be researched. August 20, 2012  What's happening near the center of this cluster of galaxies? At first glance, it appears that several strangely elongated galaxies and fully five bright quasars exist there. In reality, an entire cluster of galaxies is acting as a gigantic gravitational lens that distorts and multiply-images bright objects that occur far in the distance. The five bright white points near the cluster center are actually images of a single distant quasar. This Hubble Space Telescope image is so detailed that even the host galaxy surrounding the quasar is visible. Close inspection of the above image will reveal that the arced galaxies at 2 and 4 o'clock are actually gravitationally lensed images of the same galaxy. A third image of that galaxy can be found at about 10 o'clock from the cluster center. Serendipitously, numerous strange and distant galaxies dot the above image like colorful jewels. The cluster of galaxy that acts as the huge gravitational lens is cataloged as SDSS J1004+4112 and lies about 7 billion light years distant toward the constellation of Leo Minor. August 19, 2012   I visited Wasaga Beach for the weekend, and head home in just over a few hours as of this post, but I noticed that it was a particularily clear and moonless night - a rather cool night also helped improve atmospheric seeing conditions. I brought my camera up with me just like I do every time I head up here, and planted myself at a small urban park and could easily see Saggitarious's Tea Pot and Scorpius pulling the milky way - however I could not see the milky way myself at this point. From my prior experience in Cyprus Lake However (the 2nd picture), I knew that Scorpius pulls the bulge of the milky way. So I positioned my camera accordingly and this was the result. After taking a few photos of 2 minute exposures each, I could see the faint, washed out milky way for myself; even though Wasaga Beach does have a large amount of street lights. I suppose it is very helpful that the bulge of the milky way was in the west - precisely where huge Lake Huron borders the town here. These 2 shots are the same part of the Milky Way - the only difference is the amount of light pollution near by. The top photo is in the middle of Wasaga Beach, the second photo is 400km from my home city. August 18, 2012  What does the Curiosity rover look like on Mars? To help find out, NASA engineers digitally synthesized multiple navigation camera images taken last week into what appears to be the view of a single camera. Besides clods of Martian dirt, many of Curiosity's science instruments are visible and appear in good shape. Near the middle of the rover is an augmented reality tag intended to enable smartphones to provide background information. Far in the distance is a wall of Gale Crater. As Curiosity will begin to roll soon, its first destination has now been chosen: an intriguing intersection of three types of terrain named Glenelg. August 17, 2012  Magnificent island universe NGC 5033 lies some 40 million light-years away in the well-trained northern constellation Canes Venatici. This telescopic portrait reveals striking details of dust lanes winding near the galaxy's bright core and majestic but relatively faint spiral arms. Speckled with pink star forming regions and massive blue star clusters, the arms span over 100,000 light-years, similar in size to our own spiral Milky Way. A well-studied example of the class of Seyfert active galaxies, NGC 5033 has a core that is very bright and variable. The emission is likely powered by a supermassive black hole. The bright nucleus and rotational center of the galaxy also seem to be slightly offset, suggesting NGC 5033 is the result of an ancient galaxy merger. August 16, 2012  NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. This colorful portrait of the nebula uses narrow band image data combined in the Hubble palatte. It shows emission from sulfur, hydrogen, and oxygen atoms in the wind-blown nebula in red, green and blue hues. NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years away. August 15, 2012  If you could stand on Mars, what would you see? The above image is a digitally re-colored approximation of what you might see if the above Martian landscape had occurred on Earth. Images from Mars false-colored in this way are called white balanced and useful for planetary scientists to identify rocks and landforms similar to Earth. The image is a high resolution version of a distant wall of Gale Crater captured by the Curiosity rover that landed on Mars last week. A corresponding true colour image exists showing how this scene actually appears on Mars. The robotic Curiosity rover continues to check itself over and accept new programming from Earth before it begins to roll across Mars and explore a landscape that has the appearance of being an unusually layered dried river bed. August 14, 2012  Where will the next Perseid meteor appear? Sky enthusiasts who trekked outside for the Perseid meteor shower that peaked over the past few days typically had this question on their mind. Six meteors from this past weekend are visible in the above stacked image composite, including one bright fireball streaking along the band of the background Milky Way Galaxy. All Perseid meteors appear to come from the shower radiant in the constellation of Perseus. Early reports about this year's Perseids indicate that as many as 100 meteors per hour were visible from some dark locations during the peak. The above digital mosaic was taken near Weikersheim, Germany. August 13, 2012 What would it be like to fly through the universe? Possibly the best simulated video of this yet has been composed from recently-released galaxy data from the Sloan Digital Sky Survey. Every spot in the above video is a galaxy containing billions of stars. Many galaxies are part of huge clusters, long filaments, or small groups, while expansive voids nearly absent of galaxies also exist. The movie starts by flying right through a large nearby cluster of galaxies and later circles the SDSS-captured universe at about 2 billion light years (a redshift of about 0.15) from Earth. Analyses of galaxy positions and movements continues to bolster the case that our universe contains not only the bright matter seen, like galaxies, but also a significant amount of unseen dark matter and dark energy. August 12, 2012  This galaxy is having a bad millennium. In fact, the past 100 million years haven't been so good, and probably the next billion or so will be quite tumultuous. Visible on the upper left, NGC 4038 used to be a normal spiral galaxy, minding its own business, until NGC 4039, toward its right, crashed into it. The evolving wreckage, known famously as the Antennae, is pictured above. As gravity restructures each galaxy, clouds of gas slam into each other, bright blue knots of stars form, massive stars form and explode, and brown filaments of dust are strewn about. Eventually the two galaxies will converge into one larger spiral galaxy. Such collisions are not unusual, and even our own Milky Way Galaxy has undergone several in the past and is predicted to collide with our neighboring Andromeda Galaxy in a few billion years. The frames that compose this image were taken by the orbiting Hubble Space Telescope by professional astronomers to better understand galaxy collisions. These frames -- and many other deep space images from Hubble -- have since been made public, allowing an interested amateur to download and process them into this visually stunning composite. August 11, 2012  You've just landed on Mars and opened your eyes - what do you see? If you're the Curiosity rover, you see a strange gravelly place with a large mountain in the distance. You've landed on target near the edge of 150-km wide Gale Crater, with Mount Sharp on the horizon being the rise in the crater's center. As a car-sized rover with six wheels and a laser, you prepare yourself to go on a two-year mission of exploration, climbing Mt. Sharp, and looking for signs that Mars once harbored life. Currently you sit motionless, check yourself over, and receive a detailed briefing from Earth on things you will need to know while rolling around, trying to avoid flipping over or getting your wheels stuck in sand. Your rolling explorations will likely start in a few days. What will you find? What's out there? August 10, 2012  Denizens of planet Earth watched last year's Perseid meteor shower by looking up into the bright moonlit night sky. But this remarkable view captured on August 13, 2011 by astronaut Ron Garan looks down on a Perseid meteor. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is right of frame center, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at this year's Perseid meteor shower? You're in luck. This weekend the shower should be near its peak, with less interference from a waning crescent Moon rising a few hours before the Sun. The best time to view the showers will be around midnight tomorrow EST. August 9, 2012  Is there a monster in IC 1396? Known to some as the Elephant's Trunk Nebula, parts of the glowing gas and dust clouds of this star formation region may appear to take on foreboding forms, some nearly human. The entire nebula might even look like a face of a monster. The only real monster here, however, is a bright young star too far from Earth to be dangerous. Energetic light from this star is eating away the dust of the dark cometary globule at the top right of the image. Jets and winds of particles emitted from this star are also pushing away ambient gas and dust. Nearly 3,000 light-years distant, the IC 1396 complex is relatively faint and covers a region on the sky with an apparent width of more than 10 full moons. Recently, over 100 young stars have been discovered forming in the nebula. August 8, 2012  Just as it captured the Phoenix lander parachuting to Mars in 2008, the HiRise camera onboard the Mars Reconnaissance Orbiter (MRO) snapped this picture of the Curiosity rover's spectacular descent toward its landing site on August 5 (PDT). The nearly 16 meter (51 foot) wide parachute and its payload are caught dropping through the thin martian atmosphere above plains just north of the sand dune field that that borders the 5 kilometer high Mt. Sharp in Gale Crater. The MRO spacecraft was about 340 kilometers away when the image was made. From MRO's perspective the parachute is flying at an angle to the surface so the landing site itself does not appear below it. Dangling from tethers and still about 3 kilometers above Mars, Curiosity and its rocket powered sky crane have not yet been deployed. August 7, 2012  A wheel attached to NASA's Curiosity rover is firmly on the martian surface in this early picture from the Mars Science Laboratory mission, captured after a successful landing on August 5, 2012 at 10:32pm (PDT). Seen at the lower right of a Hazard Avoidance Camera fisheye wide-angle image, the rover's left rear wheel is 50 centimeters (about 20 inches) in diameter. Part of a spring hinge for the camera's dust cover is just visible in the right corner, while at the upper left is part of the rover's RTG power source. Looking into the Sun across the rock stewn surface of Mars, distant hills on the right are the rim of Gale Crater, about 20 kilometers from the compact car-sized rover's current resting place. Larger color images are expected later in the week when the rover's mast, carrying high-resolution cameras, is deployed. August 6, 2012 Noctournal: Have you ever seen the night sky change? It does -- sometimes in beautiful and unexpected ways. To see it, though, usually requires patience. The above award winning video shows several of the possible changes in dramatic fashion with a time lapse video. Visible are sunset-illuminated clouds moving, stars of vivid colors rising, the long tail of a Comet Lovejoy rising, bright satellites crossing, a meteor exploding, a distant lightning storm approaching, skyscapes including the Magellanic Clouds rotating, and a fisheye sky rotating while the foreground becomes illuminated by moonlight. Frequently featuring an artistic human sculpture in the foreground and the southern sky in the background, the video closes with a time lapse clip of a total lunar eclipse. August 5, 2012  Stunning emission nebula IC 1396 mixes glowing cosmic gas and dark dust clouds in the high and far off constellation of Cepheus. Energized by the bright, bluish central star seen here, this star forming region sprawls across hundreds of light-years -- spanning over three degrees on the sky while nearly 3,000 light-years from planet Earth. Among the intriguing dark shapes within IC 1396, the winding Elephant's Trunk nebula lies just below center. The gorgeous color view is a composition of digitized black and white photographic plates recorded through red and blue astronomical filters. The plates were taken using the Samuel Oschin Telescope, a wide-field survey instrument at Palomar Observatory, between 1989 and 1993. August 4, 2012  Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Above and right of the Bubble's center is a hot, O star, several hundred thousand times more luminous and around 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The intriguing Bubble Nebula lies a mere 11,000 light-years away toward the boastful constellation Cassiopeia. This view of the cosmic bubble is composed of narrowband and broadband image data, capturing details in the emission region while recording a natural looking field of stars. August 3, 2012  "Beautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] ..." begins the description of the 5th entry in 18th century astronomer Charles Messier's famous catalog of nebulae and star clusters. Though it appeared to Messier to be fuzzy and round and without stars, Messier 5 (M5) is now known to be a globular star cluster, 100,000 stars or more, bound by gravity and packed into a region around 165 light-years in diameter. It lies some 25,000 light-years away. Roaming the halo of our galaxy, globular star clusters are ancient members of the Milky Way. M5 is one of the oldest globulars, its stars estimated to be nearly 13 billion years old. The beautiful star cluster is a popular target for earthbound telescopes. Even close to its dense core, the cluster's red and blue giant stars stand out with yellowish and blue hues in this sharp color image. August 2, 2012  No star dips below the horizon and the Sun never climbs above it in this remarkable image of 24 hour long star trails. Showing all the trails as complete circles, such an image could be achieved only from two places on planet Earth. This example was recorded during the course of May 1, 2012, the digital camera in a heated box on the roof of MAPO, the Martin A. Pomerantz Observatory at the South Pole. Directly overhead in the faint constellation Octans is the projection of Earth's rotational axis, the South Celestial Pole, at the center of all the star trail circles. Not so well placed as Polaris and the North Celestial Pole, the star leaving the small but still relatively bright circle around the South Celestial Pole is Beta Hydri. The inverted umbrella structure on the horizon at the right of the allsky field of view is the ground shield for the SPUD telescope. A shimmering apparition of the aurora australis also visited on this 24 hour night. August 1, 2012  You don't have to be at Monument Valley to see the Milky Way arch across the sky like this -- but it helps. Only at Monument Valley USA would you see a picturesque foreground that includes these iconic rock peaks called buttes. Buttes are composed of hard rock left behind after water has eroded away the surrounding soft rock. In the above image taken about two months ago, the closest butte on the left and the butte to its right are known as the Mittens, while Merrick Butte can be seen just further to the right. High overhead stretches a band of diffuse light that is the central disk of our spiral Milky Way Galaxy. The band of the Milky Way can be spotted by almost anyone on almost any clear night when far enough from a city and surrounding bright lights. July 31, 2012  Why does this Martian rock have so much zinc? Roughly the size and shape of a tilted coffee-table, this oddly flat, light-topped rock outcropping was chanced upon a few weeks ago by the robotic Opportunity rover currently rolling across Mars. Early last month Opportunity reached Endeavour crater, the largest surface feature it has ever encountered, and is now exploring Endeavour's rim for clues about how wet Mars was billions of years ago. Pictured above and named Tisdale 2, the unusual rock structure was probed by Opportunity last week and is now thought to be a remnant thrown off during the impact that created nearby Odyssey crater. The resulting chemical analysis of Tisdale 2, however, has shown it to have a strangely high amount of the element zinc. The reason for this is currently unknown, but might turn out to be a clue to the history of the entire region. Opportunity is already finding rocks older than any previously studied and will continue to explore several other intriguing rock formations only now glimpsed from a distance. July 30, 2012  Why did the picturesque 2010 volcanic eruption in Iceland create so much ash? Although the large ash plume was not unparalleled in its abundance, its location was particularly noticeable because it drifted across such well-populated areas. The Eyjafjallajökull volcano in southern Iceland began erupting on 2010 March 20, with a second eruption starting under the center of a small glacier on 2010 April 14. Neither eruption was unusually powerful. The second eruption, however, melted a large amount of glacial ice which then cooled and fragmented lava into gritty glass particles that were carried up with the rising volcanic plume. Pictured above during the second eruption, lightning bolts illuminate ash pouring out of the Eyjafjallajökull volcano. July 29, 2012  In the center of star-forming region 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. These stars, known collectively as star cluster R136, were captured above in visible light by the newly installed Wide Field Camera peering though the recently refurbished Hubble Space Telescope. Gas and dust clouds in 30 Doradus, also known as the Tarantula Nebula, have been sculpted into elongated shapes by powerful winds and ultraviolet radiation from these hot cluster stars. The 30 Doradus Nebula lies within a neighboring galaxy known as the Large Magellanic Cloud and is located a mere 170,000 light-years away. July 28, 2012  Brilliant Venus and bright Jupiter still rise together before dawn. The peaceful waters by a small lakeside house near Stuttgart, Germany reflect their graceful arcing trails in this composited series of exposures, recorded on the morning of July 26. A reflection of planet Earth's rotation on its axis, the concentric trails of these celestial beacons along with trails of stars are punctuated at their ends by a separate final frame in the morning skyview. Easy to pick out, Venus is brightest and near the trees close to the horizon. Jupiter arcs above it, toward the center of the image along with the compact Pleiades star cluster and V-shaped Hyades anchored by bright star Aldebaran. One trail looks wrong, though. Not concentric with the others and so not a reflection of Earth's rotation, the International Space Station streaks off the right side of this scene, glinting in sunlight as it orbits planet Earth. July 27, 2012  The largest of its kind, the High Energy Stereoscopic System (H.E.S.S.) II telescope stands in the foreground of this photo. Tilted horizontally it reflects the inverted landscape of the Namibian desert in a segmented mirror 24 meters wide and 32 meters tall, equal in area to two tennis courts. Now beginning an exploration of the Universe at extreme energies, H.E.S.S. II saw first light on July 26. Most ground-based telescopes with lenses and mirrors are hindered by the Earth's nurturing, protective atmosphere that blurs images and scatters and absorbs light. But the H.E.S.S. II telescope is a cherenkov telescope, designed to detect gamma rays - photons with over 100 billion times the energy of visible light - and actually requires the atmosphere to operate. As the gamma rays impact the upper atmosphere they produce air showers of high-energy particles. A large camera at the mirror's focus records in detail the brief flashes of optical light, called cherenkov light, created by the air shower particles. The H.E.S.S. II telescope operates in concert with the array of four other 12 meter cherenkov telescopes to provide multiple stereoscopic views of the air showers, relating them to the energies and directions of the incoming cosmic gamma rays. July 26, 2012  Framing a bright emission region this telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula the glowing cloud of interstellar gas and dust is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. About 8,000 light-years distant the nebula is understandably not the only cosmic cloud to evoke the imagery of flowers. The complex and beautiful nebula is shown here in a composite image that maps emission from ionized sulfur, hydrogen, and oxygen atoms into red, green, and blue colors. Ultraviolet radiation from young, energetic O star HDE 227018 ionizes the atoms and powers the emission from the Tulip Nebula. HDE 227018, is the bright star very near the blue arc at image center. July 25, 2012   Why is this aurora strikingly pink? When photographing picturesque Crater Lake in Oregon, USA last month, the background sky lit up with auroras of unusual colors. Although much is known about the physical mechanisms that create auroras, accurately predicting the occurrence and colors of auroras remains a topic of investigation. Typically, it is known, the lowest auroras appear green. These occur at about 100 kilometers high and involve atmospheric oxygen atoms excited by fast moving plasma from space. The next highest auroras -- at about 200 kilometers up -- appear red, and are also emitted by resettling atmospheric oxygen. Some of the highest auroras visible -- as high as 500 kilometers up -- appear blue, and are caused by sunlight-scattering nitrogen ions. When looking from the ground through different layers of distant auroras, their colors can combine to produce unique and spectacular hues, in this case rare pink hues seen above. As Solar Maximum nears over the next two years, particle explosions from the Sun are sure to continue and likely to create even more memorable nighttime displays. July 24, 2012  What's happening over the south pole of Titan? A vortex of haze appears to be forming, although no one is sure why. The above natural-color image shows the light-colored feature. The vortex was found on images taken last month when the robotic Cassini spacecraft flew by the unusual atmosphere-shrouded moon of Saturn. Cassini was only able to see the southern vortex because its orbit around Saturn was recently boosted out of the plane where the rings and moons move. Clues as to what created the enigmatic feature are accumulating, including that Titan's air appears to be sinking in the center and rising around the edges. Winter, however, is slowly descending on the south of Titan, so that the vortex, if it survives, will be plunged into darkness over the next few years. July 23, 2012  While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list. In fact, 21st century astronomers would identify it as a planetary nebula, but it's not a planet either, even though it may appear round and planet-like in a small telescope. Messier 27 (M27) is an excellent example of a gaseous emission nebula created as a sun-like star runs out of nuclear fuel in its core. The nebula forms as the star's outer layers are expelled into space, with a visible glow generated by atoms excited by the dying star's intense but invisible ultraviolet light. Known by the popular name of the Dumbbell Nebula, the beautifully symmetric interstellar gas cloud is over 2.5 light-years across and about 1,200 light-years away in the constellation Vulpecula. This impressive color composite highlights details within the well-studied central region and fainter, seldom imaged features in the nebula's outer halo. It incorporates broad and narrowband images recorded using filters sensitive to emission from sulfur, hydrogen and oxygen atoms. Can you see the remaining core of the original star that created this nebula in the centre? July 22, 2012  How do stars form? A study of star forming region W5 by the sun-orbiting Spitzer Space Telescope provides clear clues by recording that massive stars near the center of empty cavities are older than stars near the edges. A likely reason for this is that the older stars in the center are actually triggering the formation of the younger edge stars. The triggered star formation occurs when hot outflowing gas compresses cooler gas into knots dense enough to gravitationally contract into stars. Spectacular pillars, left slowly evaporating from the hot outflowing gas, provide further visual clues. In the above scientifically-colored infrared image, red indicates heated dust, while white and green indicate particularly dense gas clouds. W5 is also known as IC 1848, and together with IC 1805 form a complex region of star formation popularly dubbed the Heart and Soul Nebulas. The above image highlights a part of W5 spanning about 2,000 light years that is rich in star forming pillars. W5 lies about 6,500 light years away toward the constellation of Cassiopeia. July 21, 2012  Get out your red/blue glasses and check out this remarkable stereo view from lunar orbit. Created from two photographs (AS11-44-6633, AS11-44-6634) taken by astronaut Michael Collins during the 1969 Apollo 11 mission, the 3D anaglyph features the lunar module ascent stage, dubbed The Eagle, as it rises to meet the command module in lunar orbit on July 21. Aboard the ascent stage are Neil Armstrong and Buzz Aldrin, the first to walk on the Moon. The smooth, dark area on the lunar surface is Mare Smythii located just below the equator on the extreme eastern edge of the Moon's near side. Poised beyond the lunar horizon, is our fair planet Earth. July 20, 2012  Skygazers around planet Earth enjoyed the close encounter of planets and Moon in July 15's predawn skies. And while many saw bright Jupiter next to the slender, waning crescent, Europeans also had the opportunity to watch the ruling gas giant pass behind the lunar disk, occulted by the Moon as it slid through the night. Clouds threaten in this telescopic view from Montecassiano, Italy, but the frame still captures Jupiter after it emerged from the occultation along with all four of its large Galilean moons. The sunlit crescent is overexposed with the Moon's night side faintly illuminated by Earthshine. Lined up left to right beyond the dark lunar limb are Callisto, Ganymede, Jupiter, Io, and Europa. In fact, Callisto, Ganymede, and Io are larger than Earth's Moon, while Europa is only slightly smaller. July 19, 2012  Wandering planets Venus and Jupiter were joined by an old crescent Moon near the eastern horizon on July 15. This serene southern skyview of the much anticipated predawn conjunction includes the lovely Pleiades star cluster and bright stars Aldebaran and Betelgeuse in the celestial lineup. The radio telescope in the foreground is the Parkes 64 meter dish of New South Wales, Australia. Known for its exploration of the distant Universe at radio wavelengths, the large, steerable antenna is also famous for its superior lunar television reception. On July 21, 1969 the dish received broadcasts from the Moon that allowed denizens of planet Earth to watch the Apollo 11 moonwalk. July 18, 2012  What created this unusual hole in Mars? The hole was discovered by chance on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole appears to be an opening to an underground cavern, partly illuminated on the image right. Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation, as is the full extent of the underlying cavern. Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life. These pits are therefore prime targets for possible future spacecraft, robots, and even human interplanetary explorers. July 17, 2012 Doing something a little bit different today with a video! How do galaxies like our Milky Way form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. Green depicts (mostly) hydrogen gas in the above movie, while time is shown in billions of years since the Big Bang on the lower right. Pervasive dark matter is present but not shown. As the simulation begins, ambient gas falls into and accumulates in regions of relatively high gravity. Soon numerous proto-galaxies form, spin, and begin to merge. After about four billion years, a well-defined center materializes that dominates a region about 100,000 light-years across and starts looking like a modern disk galaxy. After a few billion more years, however, this early galaxy collides with another, all while streams of gas from other mergers rain down on this strange and fascinating cosmic dance. As the simulation reaches half the current age of the universe, a single larger disk develops. Even so, gas blobs -- some representing small satellite galaxies -- fall into and become absorbed by the rotating galaxy as the present epoch is reached and the movie ends. For our Milky Way Galaxy, however, big mergers may not be over -- recent evidence indicates that our large spiral disk Galaxy will collide and coalesce with the slightly larger Andromeda spiral disk galaxy in the next few billion years. July 16, 2012  A fifth moon has been discovered orbiting Pluto. The moon was discovered earlier this month in images taken by the Hubble Space Telescope in preparation for the New Horizons mission's scheduled flyby of Pluto in 2015. Pictured above, the moon is currently seen as only a small blip that moves around the dwarf planet as the entire system slowly orbits the Sun. The moon, given a temporary designation of S/2012 (134340) 1 or just P5 (as labeled), is estimated to span about 15 kilometers and is likely composed mostly of water-ice. Pluto remains the only famous Solar System body never visited by a human-built probe and so its origins and detailed appearance remain mostly unknown. July 15, 2012  Few cosmic vistas excite the imagination like the Orion Nebula. Also known as M42, the nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1,500 light-years away. The Orion Nebula offers one of the best opportunities to study how stars are born partly because it is the nearest large star-forming region, but also because the nebula's energetic stars have blown away obscuring gas and dust clouds that would otherwise block our view - providing an intimate look at a range of ongoing stages of starbirth and evolution. This detailed image of the Orion Nebula is the sharpest ever, constructed using data from the Hubble Space Telescope's Advanced Camera for Surveys and the European Southern Observatory's La Silla 2.2 meter telescope. The mosaic contains a billion pixels at full resolution and reveals about 3,000 stars. Click the source link, and then the picture to reveal the full resolution image, a 6000x6000 square! July 14, 2012  Awash in a sea of plasma and anchored in magnetic fields, sunspots are planet-sized, dark islands in the solar photosphere, the bright surface of the Sun. Dark because they are slightly cooler than the surrounding surface, this group of sunspots is captured in a close-up telescopic snapshot from July 11. The field of view spans nearly 100,000 miles. They lie in the center of active region AR1520, now crossing the Sun's visible face. In fact, an X-class solar flare and coronal mass ejection erupted from AR1520 on July 12, releasing some of the energy stored in the region's twisted magnetic fields. Headed this way, the coronal mass ejection is expected to arrive today and may trigger geomagnetic storms. As a result, some weekend auroral displays could grace planet Earth's skies along with Sunday's predawn conjunction of bright planets and crescent Moon. July 13, 2012  One of the last entries in Charles Messier's famous catalog, big, beautiful spiral galaxy M101 is definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way Galaxy. M101 was also one of the original spiral nebulae observed with Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. In contrast, this mulitwavelength view of the large island universe is a composite of images recorded by space-based telescopes in the 21st century. Color coded From X-rays to infrared wavelengths (high to low energies), the image data was taken from the Chandra X-ray Observatory (purple), the Galaxy Evolution Explorer ( blue), Hubble Space Telescope(yellow), and the Spitzer Space Telescope(red). While the X-ray data trace the location of multimillion degree gas around M101's exploded stars and neutron star and black hole binary star systems, the lower energy data follow the stars and dust that define M101's grand spiral arms. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away. July 12, 2012  Engraved in rock, these ancient petroglyphs are abundant in the Teimareh valley, located in the Zagros Mountains of central Iran. They likely tell a tale of hunters and animals found in the middle eastern valley 6,000 years ago or more, etched by artists in a prehistoric age. In the night sky above are star trails etched by the rotation of planet Earth during the long composite exposure made with a modern digital camera. On the left, the center of the star trail arcs is the North Celestial Pole (NCP), the extension of Earth's axis into space, with Polaris, the North Star, leaving the bright, short, stubby trail closest to the NCP. But when these petroglyphs were carved, Polaris would have made a long arc through the night. Since the Earth's rotation axis precesses like a wobbling top, 6,000 years ago the NCP was near the border of the constellations Draco and Ursa Major, some 30 degrees from its current location in planet Earth's sky. July 11, 2012  Early morning dog walkers got a visual treat last week as bright stars and planets appeared to line up. Pictured above, easily visible from left to right, were the Pleiades open star cluster, Jupiter, Venus, and the "Follower" star Aldebaran, all seen before a starry background. The image was taken from the Atacama desert in western South America. The glow of the rising Sun can be seen over the eastern horizon. Jupiter and Venus will continue to dazzle pre-dawn strollers all over planet Earth for the rest of the month, although even now the morning planets are seen projected away from the line connecting their distant stellar sky mates. July 10, 2012  Was Devils Tower once an explosive volcano? Famous for its appearance in films such as Close Encounters, the origin of Devil's Tower in Wyoming, USA is still debated, with a leading hypothesis holding that it is a hardened lava plume that probably never reached the surface to become a volcano. The lighter rock that once surrounded the dense volcanic neck has now eroded away, leaving the dramatic tower. High above, the central band of the Milky Way galaxy arches across the sky. Many notable sky objects are visible, including dark strands of the Pipe Nebula and the reddish Lagoon Nebula to the tower's right. Green grass and trees line the moonlit foreground, while clouds appear near the horizon to the tower's left. Unlike many other international landmarks, mountaineers are permitted to climb Devils Tower. July 9, 2012  What did you do over your winter vacation? If you were the Opportunity rover on Mars, you spent four months of it stationary and perched on the northern slope of Greeley Haven -- and tilted so that your solar panels could absorb as much sunlight as possible. During its winter stopover, the usually rolling robot undertook several science activities including snapping over 800 images of its surroundings, many of which have been combined into this 360-degree digitally-compressed panorama and shown in exaggerated colors to highlight different surface features. Past tracks of Opportunity can be seen toward the left, while Opportunity's dust covered solar panels cross the image bottom. Just below the horizon and right of center, an interior wall of 20-kilometer Endeavour Crater can be seen. Now that the northern Martian winter is over, Opportunity is rolling again, this time straight ahead (north). The rover is set to investigate unusual light-colored soil patches as it begins again to further explore the inside of Endeavour, a crater that may hold some of the oldest features yet visited. July 8, 2012  Sometimes both heaven and Earth erupt. In Iceland in 1991, the volcano Hekla erupted at the same time that auroras were visible overhead. Hekla, one of the most famous volcanoes in the world, has erupted at least 20 times over the past millennium, sometimes causing great destruction. The last eruption occurred only twelve years ago but caused only minor damage. The green auroral band occurred fortuitously about 100 kilometers above the erupting lava. Is Earth the Solar System's only planet with both auroras and volcanos? July 7, 2012  Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend and colleague Charles Messier as M106. Modern deep telescopic views reveal it to be an island universe -- a spiral galaxy around 30 thousand light-years across located only about 21 million light-years beyond the stars of the Milky Way. Along with a bright central core, this colorful composite image highlights youthful blue star clusters and reddish stellar nurseries tracing the galaxy's spiral arms. It also shows off remarkable reddish jets of glowing hydrogen gas. In addition to small companion galaxy NGC 4248 (bottom right) background galaxies can be found scattered throughout the frame. M106 (aka NGC 4258) is a nearby example of the Seyfert class of active galaxies, seen across the spectrum from radio to x-rays. Active galaxies are believed to be powered by matter falling into a massive central black hole. July 6, 2012  A mere 30 million light-years away, large spiral galaxy NGC 3628 (center left) shares its neighborhood in the local Universe with two other large spirals, in a magnificent grouping otherwise known as the Leo Triplet. In fact, fellow trio member M65 is near the center right edge of this deep cosmic group portrait, with M66 just above it and to the left. But, perhaps most intriguing is the spectacular tail stretching up and to the left for about 300,000 light-years from NGC 3628's warped, edge-on disk. Know as a tidal tail, the structure has been drawn out of the galaxy by gravitational tides during brief but violent past interactions with its large neighbors. Not often imaged so distinctly, the tidal tail is composed of young bluish star clusters and star-forming regions. July 5, 2012  Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices. This sharp, colorful image reveals the galaxy's bulging central core cut by obscuring dust lanes that lace NGC 4565's thin galactic plane. An assortment of other background galaxies is included in the pretty field of view, with neighboring galaxy NGC 4562 at the upper left. NGC 4565 itself lies about 40 million light-years distant and spans some 100,000 light-years. Easily spotted with small telescopes, sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed. July 4, 2012  What stands between you and the Sun? Apparently, as viewed from Paris last week, one visible thing after another. First, in the foreground, is the Basilica of the Sacred Heart, built in the late 1800s and located on the highest hill in Paris, France. Next, well behind the basilica's towers in the above image, are thin clouds forward scattering sunlight. Finally, far in the distance and slightly buried into the Sun's surface, are sunspots, the most prominent of which is sunspot region AR 1512 visible near the disk center. Since the time that this sunset image was taken, the sunspot region on the far left, AR 1515, has unleashed a powerful solar flare. Although most particles from that flare are expected to miss the Earth, sky enthusiasts are on watch for Sun events that might cause bright auroras in an invisible thing that stands between you and the Sun: the Earth's atmosphere. July 3, 2012  Humanity's robot orbiting Saturn has recorded yet another amazing view. That robot, or course, is the spacecraft Cassini, while the new amazing view includes a bright moon, thin rings, oddly broken clouds, and warped shadows. Titan, Saturn's largest moon, appears above as a featureless tan as it is continually shrouded in thick clouds. The rings of Saturn are seen as a thin line because they are so flat and imaged nearly edge on. Details of Saturn's rings are therefore best visible in the dark ring shadows visible across the giant planet's cloud tops. Since the ring particles orbit in the same plane as Titan, they appear to skewer the foreground moon, In the upper hemisphere of Saturn, the clouds show many details, including dips in long bright bands indicating disturbances in a high altitude jet stream. Recent precise measurements of how much Titan flexes as it orbits Saturn hint that vast oceans of water might exist deep underground. July 2, 2012  What causes the surrounding shells in peculiar galaxy Cen A? In 2002 a fascinating image of peculiar galaxy Centaurus A was released, processed to highlight a faint blue arc indicating an ongoing collision with a smaller galaxy. Another interesting feature of Cen A, however, is the surrounding system of shells, better visible here in this recently released wider pan from the four meter Blanco telescope at Cerro Tololo Inter-American Observatory. Faint shells around galaxies are not unusual and considered by themselves as evidence of a previous galaxy merger, analogous to water ripples on a pond. An unexpected attribute of these shells is the abundance of gas, which should become separated from existing stars during the collision. July 1, 2012  This image shows the Large Magellanic Cloud galaxy in infrared light as seen by the Herschel Space Observatory, a European Space Agency-led mission with important NASA contributions, and NASA's Spitzer Space Telescope. In the instruments' combined data, this nearby dwarf galaxy looks like a fiery, circular explosion. Rather than fire, however, those ribbons are actually giant ripples of dust spanning tens or hundreds of light-years. Significant fields of star formation are noticeable in the center, just left of center and at right. The brightest center-left region is called 30 Doradus, or the Tarantula Nebula, for its appearance in visible light. The colors in this image indicate temperatures in the dust that permeates the Cloud. Colder regions show where star formation is at its earliest stages or is shut off, while warm expanses point to new stars heating surrounding dust. The coolest areas and objects appear in red, corresponding to infrared light taken up by Herschel's Spectral and Photometric Imaging Receiver at 250 microns, or millionths of a meter. Herschel's Photodetector Array Camera and Spectrometer fills out the mid-temperature bands, shown here in green, at 100 and 160 microns. The warmest spots appear in blue, courtesy of 24- and 70-micron data from Spitzer. Herschel is a European Space Agency mission with significant NASA contributions. Launched in 2009, the spacecraft carries science instruments provided by consortia of European institutes. NASA's Herschel Project Office based at JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the U.S. astronomical community. Caltech manages JPL for NASA. June 30, 2012  Now shining in eastern skies at dawn, bright planets Venus and Jupiter join the Pleiades star cluster in this sea and sky scape, recorded earlier this week near Buenos Aires, Argentina. Venus dominates the scene that includes bright star Aldebaran just below and to the right. The planets are easy to spot for early morning risers, but this sky also holds two of our solar system's small worlds, Vesta and Ceres, not quite bright enough to be seen with the unaided eye. The digital camera's time exposure just captures them, though. Their positions are indicated when you put your cursor over the image. In orbit around Vesta, NASA's Dawn spacecraft arrived there last July, but is nearing the end of its visit to the main belt asteroid. In August, it will set off on its planned journey to Ceres, arriving at the dwarf planet in 2015. June 29, 2012  Part of a dark expanse that splits the crowded plane of our Milky Way galaxy, the Aquila Rift arcs through the northern hemisphere's summer skies near bright star Altair and the Summer Triangle In silhouette against the Milky Way's faint starlight, its dusty molecular clouds likely contain raw material to form hundreds of thousands of stars and astronomers eagerly search the clouds for telltale signs of star birth. This telescopic close-up looks toward the region at a fragmented Aquila dark cloud complex identified as LDN 673, stretching across a field of view slightly wider than the full moon. In the scene, visible indications of energetic outflows associated with young stars include the small red tinted nebulosity RNO 109 at top left and Herbig-Haro object HH32 above and right of center. The dark clouds in Aquila are estimated to be some 600 light-years away. At that distance, this field of view spans about 7 light-years. June 28, 2012  The glare of Alpha Centauri, one of the brightest stars in planet Earth's night sky, floods the left side of this southern skyscape. A mere 4.3 light-years distant, Alpha Centauri actually consists of two component stars similar in size to the Sun, locked in a mutual orbit. Much smaller and cooler, a third member of the same star system, Proxima Centauri, lies outside this field of view. Still, the telescopic scene does reveal often overlooked denizens of the Milky Way's crowded galactic plane that lie beyond the glare of Alpha Centauri, including a planetary nebula cataloged as Hen 2-111, an estimated 7,800 light-years away. The gaseous shroud of a dying star, the nebula's brighter core and fainter halo of reddish ionized gas span over twenty light-years, seen just right of picture center. Farther right are two notable open clusters of stars, the compact Pismis 19 also nearly 8,000 light-years away whose light is reddened by intervening dust, and the looser, closer NGC 5617. Just visible in the glare of Alpha Centauri is the dim glow of a shell-like supernova remnant, above and right of the closest star system's bright core. June 27, 2012  When stars form, pandemonium reigns. A particularly colorful case is the star forming region Simeis 188 which houses an unusual and bright cloud arc cataloged as NGC 6559. Visible above are red glowing emission nebulas of hydrogen, blue reflection nebulas of dust, dark absorption nebulas of dust, and the stars that formed from them. The first massive stars formed from the dense gas will emit energetic light and winds that erode, fragment, and sculpt their birthplace. And then they explode. The resulting morass can be as beautiful as it is complex. After tens of millions of years, the dust boils away, the gas gets swept away, and all that is left is a naked open cluster of stars. Simeis 188 is located about 4,000 light years away and can be found about one degree northeast of M8, the Lagoon Nebula. June 26, 2012  What time is it? If the time and day are right, this sundial will tell you: SOLSTICE. Only then will the Sun be located just right for sunlight to stream through openings and spell out the term for the longest and shortest days of the year. And that happened last week and twice each year. The sundial was constructed by Jean Salins in 1980 and is situated at the Ecole Supérieure des Mines de Paris in Valbonne Sophia Antipolis of south-eastern France. On two other days of the year, watchers of this sundial might get to see it produce another word: EQUINOXE. June 25, 2012  Sometimes, if you wait long enough for a clear and moonless night, the stars will come out with a vengeance. One such occasion occurred earlier this month at the Piton de l'Eau on Reunion Island. In the foreground, surrounded by bushes and trees, lies a water filled volcanic crater serenely reflecting starlight. A careful inspection near the image center will locate Piton des Neiges, the highest peak on the island, situated several kilometers away. In the background, high above the lake, shines the light of hundreds of stars, most of which are within 100 light years, right in our stellar neighborhood. Far is the distance, arching majestically overhead, is the central band of our home Milky Way Galaxy, shining by the light of millions of stars each located typically thousands of light years away. The astrophotographer reports waiting for nearly two years for the sky and clouds to be just right to get the above shot. June 24, 2012  In December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon in the Taurus-Littrow valley, while colleague Ronald Evans orbited overhead. This sharp image was taken by Cernan as he and Schmitt roamed the valley floor. The image shows Schmitt on the left with the lunar rover at the edge of Shorty Crater, near the spot where geologist Schmitt discovered orange lunar soil. The Apollo 17 crew returned with 110 kilograms of rock and soil samples, more than was returned from any of the other lunar landing sites. Now forty years later, Cernan and Schmitt are still the last to walk on the Moon. June 23, 2012  As seen from Frösön island in northern Sweden the Sun did set a day after the summer solstice. From that location below the arctic circle it settled slowly behind the northern horizon. During the sunset's final minute, this remarkable sequence of 7 images follows the distorted edge of the solar disk as it just disappears against a distant tree line, capturing both a green and blue flash. Not a myth even in a land of runes, the colorful but ellusive glints are caused by atmospheric refraction enhanced by long, low, sight lines and strong atmospheric temperature gradients. June 22, 2012  Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small, irregular galaxies form stars too. In fact dwarf galaxy IC 2574 shows clear evidence of intense star forming activity in its telltale pinkish regions of glowing hydrogen gas. Just as in spiral galaxies, the turbulent star-forming regions in IC 2574 are churned by stellar winds and supernova explosions spewing material into the galaxy's interstellar medium and triggering further star formation. A mere 12 million light-years distant, IC 2574 is part of the M81 group of galaxies, seen toward the northern constellation Ursa Major. Also known as Coddington's Nebula, the lovely island universe is about 50,000 light-years across, discovered by American astronomer Edwin Coddington in 1898. June 21, 2012  Made with narrow and broad band filters, this colorful cosmic snap shot covers a field of view about the size of the full Moon within the boundaries of the constellation Cygnus. It highlights the bright edge of a ring-like nebula traced by the glow of ionized hydrogen and oxygen gas. Embedded in the region's interstellar clouds of gas and dust, the complex, glowing arcs are sections of bubbles or shells of material swept up by the wind from Wolf-Rayet star WR 134, brightest star near the center of the frame. Distance estimates put WR 134 about 6,000 light-years away, making the frame over 50 light-years across. Shedding their outer envelopes in powerful stellar winds, massive Wolf-Rayet stars have burned through their nuclear fuel at a prodigious rate and end this final phase of massive star evolution in a spectacular supernova explosion. The stellar winds and final supernovae enrich the interstellar material with heavy elements to be incorporated in future generations of stars. June 20, 2012  How was this unusual looking galaxy created? No one is sure, especially since spiral galaxy NGC 7049 looks so strange. NGC 7049's striking appearance is primarily due to an unusually prominent dust ring seen mostly in silhouette. The opaque ring is much darker than the din of millions of bright stars glowing behind it. Besides the dark dust, NGC 7049 appears similar to a smooth elliptical galaxy, although featuring surprisingly few globular star clusters. NGC 7049 is pictured above as imaged recently by the Hubble Space Telescope. The bright star near the top of NGC 7049 is an unrelated foreground star in our own Galaxy. Not visible here is an unusual central polar ring of gas circling out of the plane near the galaxy's center. Since NGC 7049 is the brightest galaxy in its cluster of galaxies, its formation might be fostered by several prominent and recent galaxy collisions. NGC 7049 spans about 150 thousand light years and lies about 100 million light years away toward the constellation of Indus. June 19, 2012  During July 22nd's 2009 solar eclipse, the Moon's dark shadow traced a narrow path as it raced eastward across India and China and on into the Pacific. Hong Kong was south of the shadow's path, so a total eclipse was not visible there, but a partial eclipse was still enjoyed by inhabitants of the populous city. And while many were (safely!) watching the sky, images of the partially eclipsed Sun adorned the city itself. In this downlooking photo, taken at 9:40am local time, a remarkable array of solar eclipse views was created by reflection in a grid of eastward facing skyscraper windows. The photographer's location was the 27th floor of Two Pacific Place. June 18, 2012  Why were the statues on Easter Island built? No one is sure. What is sure is that over 800 large stone statues exist there. The Easter Island statues, stand, on the average, over twice as tall as a person and have over 200 times as much mass. Few specifics are known about the history or meaning of the unusual statues, but many believe that they were created about 500 years ago in the images of local leaders of a lost civilization. Pictured above, some of the stone giants were illuminated in 2009 under the central band of our Milky Way Galaxy. June 17, 2012  Why does Jupiter have rings? Jupiter's rings were discovered in 1979 by the passing Voyager 1 spacecraft, but their origin was a mystery. Data from the Galileo spacecraft that orbited Jupiter from 1995 to 2003 later confirmed that these rings were created by meteoroid impacts on small nearby moons. As a small meteoroid strikes tiny Adrastea, for example, it will bore into the moon, vaporize, and explode dirt and dust off into a Jovian orbit. Pictured above is an eclipse of the Sun by Jupiter, as viewed from Galileo. Small dust particles high in Jupiter's atmosphere, as well as the dust particles that compose the rings, can be seen by reflected sunlight. June 16, 2012  Why does this galaxy have such a long tail? In this stunning vista recorded with the Hubble Space Telescope's Advanced Camera for Surveys, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic tadpole is a mere 420 million light-years distant toward the northern constellation Draco. Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story goes that a more compact intruder galaxy crossed in front of Arp 188 - from left to right in this view - and was slung around behind the Tadpole by their gravitational attraction. During the close encounter, tidal forces drew out the spiral galaxy's stars, gas, and dust forming the spectacular tail. The intruder galaxy itself, estimated to lie about 300 thousand light-years behind the Tadpole, can be seen through foreground spiral arms at the lower left. Following its terrestrial namesake, the Tadpole Galaxy will likely lose its tail as it grows older, the tail's star clusters forming smaller satellites of the large spiral galaxy. June 15, 2012  Nearby and bright, spiral galaxies M65 (top) and M66 stand out in this engaging cosmic snapshot. The pair are just 35 million light-years distant and around 100,000 light-years across, about the size of our own spiral Milky Way. While both exhibit prominent dust lanes sweeping along their broad spiral arms, M66 in particular is a striking contrast in red and blue hues; the telltale pinkish glow of hydrogen gas in star forming regions and young blue star clusters. M65 and M66 make up two thirds of the well-known Leo Triplet of galaxies with warps and tidal tails that offer evidence of the group's past close encounters. The larger M66 has been host to four supernovae discovered since 1973. June 14, 2012  In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent." Of course, M13 is now modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Telescopic views reveal the spectacular cluster's hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter, but approaching the cluster core upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away. Along with the cluster's dense core, the outer reaches of M13 are highlighted in this sharp color image. The cluster's evolved red and blue giant stars show up in yellowish and blue tints. June 13, 2012  Waiting years and traveling kilometers -- all to get a shot like this. And even with all of this planning, a good bit of luck was helpful. As the Sun rose over the Baltic Sea last Wednesday as seen from Fehmarn Island in northern Germany, photographer Jens Hackmann was ready for the very unusual black dot of Venus to appear superimposed. Less expected were the textures of clouds and haze that would tint different levels of the Sun various shades of red. And possibly the luckiest gift of all was a flicker of a rare green flash at the very top of the Sun. The above image is, of course, just one of many spectacular pictures taken last week of the last transit of the planet Venus across the face of the Sun for the next 105 years. June 12, 2012  These are larger dust bunnies than you will find under your bed. Situated in rich star fields and glowing hydrogen gas, these opaque clouds of interstellar dust and gas are so large they might be able to form stars. Their home is known as IC 2944, a bright stellar nursery located about 5,900 light years away toward the constellation of Centaurus. The largest of these dark globules, first spotted by South African astronomer A. D. Thackeray in 1950, is likely two separate but overlapping clouds, each more than one light-year wide. Along with other data, the above representative color image from the 4-m Blanco telescope at Cerro Tololo, Chile indicates that Thackeray's globules are fractured and churning as a result of intense ultraviolet radiation from young, hot stars already energizing and heating the bright emission nebula. These and similar dark globules known to be associated with other star forming regions may ultimately be dissipated by their hostile environment - like cosmic lumps of butter in a hot frying pan. June 11, 2012  Few butterflies have a wingspan this big. The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects, and NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the central star of this particular planetary nebula is exceptionally hot though -- shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. This dramatically detailed close-up of the dying star's nebula was recorded by the Hubble Space Telescope soon after it was upgraded in 2009. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius). June 10, 2012  What if you were given a new Hubble telescope for free? How about two? The astronomical community is abuzz with just this opportunity as the US National Reconnaissance Office has unexpectedly transferred ownership of two space-qualified Hubble-quality telescopes to NASA. The usefulness of these telescopes in addressing existing science priorities has begun, but preliminary indications hold that even one of these telescope could be extremely useful in searching for extrasolar planets as well as distant galaxies and supernovas that could better explore the nature of dark energy. Although they start out as free, making even one telescope operational and fitting it with useful cameras would be quite expensive, so NASA is being decidedly careful about how to fit these new telescopes into its existing budget. Pictured above, the original Hubble Space Telescope floats high above the Earth during a servicing mission in 2002. June 9, 2012 As its June 6 2012 transit begins Earth's sister planet crosses the edge of the Sun in this stunning view from the Hinode spacecraft. The timing of limb crossings during the rare transits was used historically to triangulate the distance to Venus and determine a value for the Earth-Sun distance called the astronomical unit. Still, modern space-based views like this one show the event against an evocative backdrop of the turbulent solar surface with prominences lofted above the Sun's edge by twisting magnetic fields. Remarkably, the thin ring of light seen surrounding the planet's dark silhouette is sunlight refracted by Venus' thick atmosphere. June 8, 2012  This dramatic telephoto view across the Black Sea on June 6 finds Venus rising with the Sun, the planet in silhouette against a ruddy and ragged solar disk. Of course, the reddened light is due to scattering in planet Earth's atmosphere and the rare transit of Venus didn't influence the strangely shaped and distorted Sun. In fact, seeing the Sun in the shape of an Etruscan Vase is relatively common, especially compared to Venus transits. At sunset and sunrise, the effects of atmospheric refraction enhanced by long, low, sight lines and strong atmospheric temperature gradients produce the visual distortions and mirages. That situation is often favored by a sea horizon. June 7, 2012  Occurring in pairs separated by over a hundred years, there have now been only eight transits of Venus since the invention of the telescope in 1608. The next will be in December of 2117. But many modern telescopes and cameras were trained on this week's Venus transit, capturing the planet in rare silhouette against the Sun. In this sharp telescopic view from Georgia, USA, a narrowband H-alpha filter was used to show the round planetary disk against a mottled solar surface with dark filaments, sunspots, and prominences. The transit itself lasted for 6 hours and 40 minutes. Historically, astronomers used timings of the transit from different locations to triangulate the distance to Venus, while modern astronomers actively search for planets that transit distant suns. June 6, 2012  A setting full moon rarely looks like this. Monday morning just before a fully lit Strawberry Moon dropped behind the Absaroka Mountain Range near Cody, Wyoming, USA, the shadow of the Earth got in the way. A similarly setting partial lunar eclipse was visible throughout most of North and South America, while simultaneously the same partially darkened moon was visible throughout eastern Asia. Pictured in the foreground is a snowbank formation known as the Horse's Head off a tributary of the Shoshone River. Lunar eclipses occur about twice a year, and the next one -- a penumbral eclipse -- will occur in late November. June 5, 2012  Today Venus moves in front of the Sun. One way to follow this rare event is to actively reload the above live image of the Sun during the right time interval and look for an unusual circular dark dot. The smaller sprawling dark areas are sunspots. The circular dot is the planet Venus. The dark dot will only appear during a few very specific hours, from about 22:10 on 2012 June 5 through 4:50 2012 June 6, Universal Time. This transit is the rarest type of solar eclipse known -- much more rare than an eclipse of the Sun by the Moon or even by the planet Mercury. In fact, the next transit of Venus across the Sun will be in 2117. Anyone with a clear view of the Sun can go outside and carefully view the transit for themselves by projecting sunlight through a hole in a card onto a wall. Because this Venus transit is so unusual and visible from so much of the Earth, it is expected to be one of the more photographed celestial events in history. The above live image on the Sun is being taken by the Earth-orbiting Solar Dynamics Observatory and can be updated about every 15 minutes. June 4, 2012  Will our Milky Way Galaxy collide one day with its larger neighbor, the Andromeda Galaxy? Most likely, yes. Careful plotting of slight displacements of M31's stars relative to background galaxies on recent Hubble Space Telescope images indicate that the center of M31 could be on a direct collision course with the center of our home galaxy. Still, the errors in sideways velocity appear sufficiently large to admit a good chance that the central parts of the two galaxies will miss, slightly, but will become close enough for their outer halos to become gravitationally entangled. Once that happens, the two galaxies will become bound, dance around, and eventually merge to become one large elliptical galaxy -- over the next few billion years. Pictured above is an artist's illustration of the sky of a world in the distant future when the central parts of each galaxy begin to destroy each other. The exact future of our Milky Way and the entire surrounding Local Group of Galaxies is likely to remain an active topic of research for years to come. June 3, 2012  The rare transit of Venus across the face of the Sun in 2004 was one of the better-photographed events in sky history. Both scientific and artistic images flooded in from the areas that could see the transit: Europe and much of Asia, Africa, and North America. Scientifically, solar photographers confirmed that the black drop effect is really better related to the viewing clarity of the camera or telescope than the atmosphere of Venus. Artistically, images might be divided into several categories. One type captures the transit in front of a highly detailed Sun. Another category captures a double coincidence such as both Venus and an airplane simultaneously silhouetted, or Venus and the International Space Station in low Earth orbit. A third image type involves a fortuitous arrangement of interesting looking clouds, as shown by example in the above image taken from North Carolina, USA. Sky enthusiasts worldwide are abuzz about the coming transit of Venus on Tuesday. It is perhaps interesting to wonder whether any person will live to see - and remember seeing - both Tuesday's Venus transit and the next one in 2117. If they were born today, they would be 105 before they get to see the next one! June 2, 2012  The 51st entry in Charles Messier's famous catalog is perhaps the original spiral nebula - a large galaxy with a well defined spiral structure also cataloged as NGC 5194. Over 60,000 light-years across, M51's spiral arms and dust lanes clearly sweep in front of its companion galaxy (top), NGC 5195. Image data from the Hubble's Advanced Camera for Surveys has been reprocessed to produce this alternative portrait of the well-known interacting galaxy pair. The processing has further sharpened details and enhanced color and contrast in otherwise faint areas, bringing out dust lanes and extended streams that cross the small companion, along with features in the surroundings and core of M51 itself. The pair are about 31 million light-years distant. Not far on the sky from the handle of the Big Dipper, they officially lie within the boundaries of the small constellation Canes Venatici. June 1, 2012  These three bright nebulae are often featured in telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula left of center, and colorful M20 on the right. The third, NGC 6559, is above M8, separated from the larger nebula by a dark dust lane. All three are stellar nurseries about five thousand light-years or so distant. The expansive M8, over a hundred light-years across, is also known as the Lagoon Nebula. M20's popular moniker is the Trifid. Glowing hydrogen gas creates the dominant red color of the emission nebulae, with contrasting blue hues, most striking in the Trifid, due to dust reflected starlight. This broad skyscape also includes one of Messier's open star clusters, M21, just above and right of the Trifid. May 31, 2012  Comet Lovejoy (C/2011 W3) survived its close encounter with the Sun earlier this month, taking its place among wonders of the southern skies just in time for Christmas. Seen here before sunrise from Paranal Observatory in Chile, the sungrazing comet's tails stretch far above the eastern horizon. Spanning over 20 degrees they rise alongside the plane of the our Milky Way galaxy. A breathtaking spectacle in itself, Lovejoy performs on this celestial stage with southern stars and nebulae, including the Large and Small Magellanic clouds right of the telescope dome, and the glow of zodiacal light along the left edge of the frame. With Paranal's Very Large Telescope units in the foreground, this wide-angle scene was captured on December 23. Receding from the Sun, Comet Lovejoy's tails have continued to grow in length even as the comet fades. May 30, 2012  What's that dark spot on planet Earth? It's the shadow of the Moon. The above image of Earth was taken last week by MTSAT during an annular eclipse of the Sun. The dark spot appears quite unusual as clouds are white and the oceans are blue in this color corrected image. Earthlings residing within the dark spot would see part of the Sun blocked by the Moon and so receive less sunlight than normal. The spot moved across the Earth at nearly 2,000 kilometers per hour, giving many viewers less than two hours to see a partially eclipsed Sun. MTSAT circles the Earth in a geostationary orbit and so took the above image from about three Earth-diameters away. Sky enthusiasts might want to keep their eyes pointed upward this coming week as a partial eclipse of the Moon will occur on June 4 and a transit of Venus across the face of the Sun will occur on June 5. May 29, 2012  Who guards the north? Judging from the above photograph, possibly giant trees covered in snow and ice. The picture was taken last winter in Finnish Lapland where weather can include sub-freezing temperatures and driving snow. Surreal landscapes sometimes result, where common trees become cloaked in white and so appear, to some, as watchful aliens. Far in the distance, behind this uncommon Earthly vista, is a more common sight -- a Belt of Venus that divided a darkened from sunlit sky as the Sun rose behind the photographer. The Belt of Venus can be seen every day granted clear skies; it is the earthès shadow and the first signs of night sky. It can be found opposite the sun at sunset. Of course, in the spring, the trees have thawed and Lapland looks much different. May 28, 2012  Have you contemplated your home star recently? Pictured above, a Sun partially eclipsed on the top left by the Moon is also seen eclipsed by earthlings contemplating the eclipse below. The above menagerie of silhouettes was taken from the Glenn Canyon National Recreational Area near Page, Arizona, USA, where park rangers and astronomers expounded on the unusual event to interested gatherers. Also faintly visible on the Sun's disk, just to the lower right of the dark Moon's disk, is a group of sunspots. Although exciting, some consider this event a warm-up act for next week's chance to comtemplate the Sun - a much more rare partial eclipse by the planet Venus. May 27, 2012  Can you spot the planet? The diminutive disk of Mercury, the solar system's innermost planet, spent about five hours crossing in front of the enormous solar disk in 2003, as viewed from the general vicinity of planet Earth. The Sun was above the horizon during the entire transit for observers in Europe, Africa, Asia, or Australia, and the horizon was certainly no problem for the sun-staring SOHO spacecraft. Seen as a dark spot, Mercury progresses from left to right (top panel to bottom) in these four images from SOHO's extreme ultraviolet camera. The panels' false-colors correspond to different wavelengths in the extreme ultraviolet which highlight regions above the Sun's visible surface. This was the first of 14 transits of Mercury which will occur during the 21st century. Next week, however, an event much more rare but easier to spot will occur - a transit of Venus across the Sun. Mercury is found moving left to right in these images. May 26, 2012  This sharp cosmic portrait features NGC 891. The spiral galaxy spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30 million light-years distant in the constellation Andromeda, NGC 891 looks a lot like our Milky Way. At first glance, it has a flat, thin, galactic disk and a central bulge cut along the middle by regions of dark obscuring dust. The combined image data also reveals the galaxy's young blue star clusters and telltale pinkish star forming regions. And remarkably apparent in NGC 891's edge-on presentation are filaments of dust that extend hundreds of light-years above and below the center line. The dust has likely been blown out of the disk by supernova explosions or intense star formation activity. Faint neighboring galaxies can also been seen near this galaxy's disk. May 25, 2012  It was a typical Texas sunset except that most of the Sun was missing. The location of the missing piece of the Sun was not a mystery -- it was behind the Moon. Sunday night's partial eclipse of the Sun by the Moon turned into one of the best photographed astronomical events in history. Gallery after online gallery is posting just one amazing eclipse image after another. Pictured above is possibly one of the more interesting posted images -- a partially eclipsed Sun setting in a reddened sky behind brush and a windmill. The image was taken Sunday night from about 20 miles west of Sundown, Texas, USA, just after the ring of fire effect was broken by the Moon moving away from the center of the Sun. Coming early next month is an astronomical event that holds promise to be even more photographed -- the last partial eclipse of the Sun by Venus until the year 2117. May 24, 2012 This is part 3 of 3 of photos that I am posting from my adventures over the weekend. The first image here shows a satellite that I managed to capture while viewing the night sky early in the evening. (When I say early, I mean around 10pm). Closer inspection of my satellite chart for objects brighter than magnitude 3 revealed this was COSMOS 1939 ROCKET flying overhead. Those rockets that are thrown off space shuttles and such don't always fall back down to the Earth you know - some of them are stuck in orbit. The other photo is a view from my campsite when you look up in the sky. It's a much nicer view than in the city where you simply see brown and maybe a select few stars. One thing I couldn't get over was how much brigher stars I thought I knew were - I had a hard time pointing out constellations that I see almost daily becuase of this! I would like to revisit sometime in October or the winter - when Orion and the Pleiades are in the sky, and the Winter Triangle dominates the night. What a sight that would be. May 23, 2012 This is part 2 of 3 of photos that I am posting from my adventures over the weekend. Part 2 is the wonderful milky way that quietly greets us every night, yet we fail to see it in such light polluted skies. In the lands of Cyprus Lake, walking about 3km away from my campsite with no city lights anywhere, I used my red flashlight to navigate my way to this opening, where around 2am I was greeted by the rising milky way which was following a quick moving Scorpius. Being my first time witnessing the whole thing, I wish I had words to describe how it happened, but there is this amusing little story behind the discovery; it took about 20 minutes for my eyes to fully adapt to the milky way. Around this time I happened to be greeted by a few noticably drunk adventurers who were trying to find something in the woods, don't ask me what because I don't know. We look towards the North east, noting a faint cloud in the sky that appeared to have stars in front of it. I pointed my camera and shot the first photograph, and it was after looking at that photograph we all realised what we were seeing, and we could see it clearly immediately after this. The drunk guys said thanks for showing us, and decided to part ways, but not before one of them walked into a tree and needed help from someone to get back up. I don't know when, but I will return up here again. May 22, 2012 This is part 1 of 3 of photos that I am posting from my adventures over the weekend. Part 1 is the annular solar eclipse that occured at sunset on the 20th for me. As I was still very far east I was unable to see the whole show, but I still came up with this. For some, this was the first chance to see a solar eclipse in about a decade. Something about watching this occur while seeing the reflection on the water slowly adjust with the real spectacle was stunning, nature at its finest. Oh and the best part is I didn't blind myself in the process! This was taken at Cyprus Lake near Tobermory. May 21, 2012  How can two stars create such a strange and intricate structure? Most stars are members of multiple-star systems. Some stars are members of close binary systems where material from one star swirls around the other in an accretion disk. Only a handful of stars, however, are members of an intermediate polar, a system featuring a white dwarf star with a magnetic field that significantly pushes out the inner accretion disk, only allowing material to fall down its magnetic poles. Shown above is an artist's depiction of an intermediate polar system, also known as a DQ Hercules system. The foreground white dwarf is so close to the normal star that it strips away its outer atmosphere. As the white dwarf spins, the columns of infalling gas rotate with it. The name intermediate polar derives from observations of emitted light polarized at a level intermediate to non-disk binary systems known as polars. Intermediate polars are a type of cataclysmic variable star system. May 20, 2012  Did you see that flash? Lasting only about 15 seconds, it's possible that nobody you ask can confirm it, but what you might have seen is sunlight reflecting off an orbiting Iridium satellite. Satellites of all types have been providing streaks and glints visible only since the launch of Sputnik I in 1957. Of these, flares from any of the 66 Iridium satellites can be particularly bright, sometimes even approaching the brightness of the Moon. If the Iridium satellites are programmed to re-enter the Earth's atmosphere, they might provide even brighter flares as they burn up. Pictured above, the streak from an Iridium satellite punctuates a picturesque sunset in San Sebastian, Spain. Then again, that sky-flash you saw? If it lasted only a second or two, it might have been a meteor. May 19, 2012  On June 15, the totally eclipsed Moon was very dark, with the Moon itself positioned on the sky toward the center of our Milky Way Galaxy. This simple panorama captures totality from northern Iran in 8 consecutive exposures each 40 seconds long. In the evocative scene, the dark of the eclipsed Moon competes with the Milky Way's faint glow. The tantalizing red lunar disk lies just above the bowl of the dark Pipe Nebula, to the right of the glowing Lagoon and Trifid nebulae and the central Milky Way dust clouds. At the far right, the wide field is anchored by yellow Antares and the colorful clouds of Rho Ophiuchi. To identify other sights of the central Milky Way just slide your cursor over the image. The total phase of this first lunar eclipse of 2011 lasted an impressive 100 minutes. Parts of the eclipse were visible from most of planet Earth, with notable exceptions of North and Central America. While the Milky Way Bluearrowll is probably seeing right now (weather permitting) is not going to feature a total eclipse deep in it, tomorrow's Annular Solar Eclipse should more than make up for that. May 18, 2012  On June 1, the shadow of the New Moon was cast across a land of the midnight Sun in last year's second partial solar eclipse. This picture of the geocentric celestial event above the Arctic Circle was taken near midnight from northern Finland's Kaunispää Hill in Lapland. Of course the region's reindeer were able to watch as both Moon and Sun hugged the northern horizon just above a cloud bank. Also visible from parts of Alaska and Canada, the eclipse began at sunrise in Siberia and northern China at 19:25 UT, ending about 3.5 hours later north of Newfoundland in the Atlantic Ocean. Remarkably, just one lunation later, on July 1 the New Moon's shadow again reached out and touched the Earth in a partial solar eclipse, limited in visibility to a relatively small area in the Antarctic Ocean. This is the beginning of what most people are going to see in the evening around around or before sundown in the United States on May 20th. May 17, 2012  The Herschel Space Observatory's infrared view of Cygnus X spans some 6x2 degrees across one of the closest, massive star forming regions in the plane of our Milky Way galaxy. In fact, the rich stellar nursery already holds the massive star cluster known as the Cygnus OB2 association. But those stars are more evident by the region cleared by their energetic winds and radiation near the bottom center of this field, and are not detected by Herschel instruments operating at long infrared wavelengths. Herschel does reveal the region's complex filaments of cool gas and dust that lead to dense locations where new massive stars are forming. Cygnus X lies some 4500 light-years away toward the heart of the northern constellation of the Swan. At that distance this picture would be almost 500 light-years wide. May 16, 2012  How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius. The above illustration shows what would happen if all of the water on or near the surface of the Earth were bunched up into a ball. The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth's Moon, but slightly larger than Saturn's moon Rhea which, like many moons in our outer Solar System, is mostly water ice. How even this much water came to be on the Earth and whether any significant amount is trapped far beneath Earth's surface remain topics of research. May 15, 2012  Earth Observatory - Total Solar Eclipse of March 29, 2006: The International Space Station (ISS) was in position to view the umbral (ground) shadow cast by the Moon as it moved between the Sun and the Earth during the solar eclipse on March 29, 2006. This astronaut image captures the umbral shadow across southern Turkey, northern Cyprus, and the Mediterranean Sea. To the casual observer who is outside the world, they would see a black blotch such as the one shown here cutting through the bright daylight sphere; a black void in a world of blues and greens. The photo also helps illustrate why on the ground, the sky gets very dark during a total solar eclipse. May 14, 2012  In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn recently drifted in giant planet's shadow for about 12 hours and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn, slightly scattering sunlight, in this exaggerated color image. Saturn's rings light up so much that new rings were discovered, although they are hard to see in the image. Seen in spectacular detail, however, is Saturn's E ring, the ring created by the newly discovered ice-fountains of the moon Enceladus and the outermost ring visible above. Far in the distance, at the left, just above the bright main rings, is the almost ignorable pale blue dot of Earth. May 13, 2012  Unspeakable beauty and unimaginable bedlam can be found together in the Trifid Nebula. Also known as M20, this photogenic nebula is visible with good binoculars towards the constellation of Sagittarius. The energetic processes of star formation create not only the colors but the chaos. The red-glowing gas results from high-energy starlight striking interstellar hydrogen gas. The dark dust filaments that lace M20 were created in the atmospheres of cool giant stars and in the debris from supernovae explosions. Which bright young stars light up the blue reflection nebula is still being investigated. The light from M20 we see today left perhaps 3,000 years ago, although the exact distance remains unknown. Light takes about 50 years to cross M20. May 12, 2012  Two stars within our own Milky Way galaxy anchor the foreground of this cosmic snapshot. Beyond them lie the galaxies of the Hydra Cluster. In fact, while the spiky foreground stars are hundreds of light-years distant, the Hydra Cluster galaxies are over 100 million light-years away. Three large galaxies near the cluster center, two yellow ellipticals (NGC 3311, NGC 3309) and one prominent blue spiral (NGC 3312), are the dominant galaxies, each about 150,000 light-years in diameter. An intriguing overlapping galaxy pair cataloged as NGC 3314 is just above and left of NGC 3312. This was yesterday's Picture of the Day. Can you spot it? Also known as Abell 1060, the Hydra galaxy cluster is one of three large galaxy clusters within 200 million light-years of the Milky Way. In the nearby universe, galaxies are gravitationally bound into clusters which themselves are loosely bound into superclusters that in turn are seen to align over even larger scales. At a distance of 100 million light-years this picture would be about 1.3 million light-years across. May 11, 2012  NGC 3314 is actually two large spiral galaxies which just happen to almost exactly line up. The foreground spiral is viewed nearly face-on, its pinwheel shape defined by young bright star clusters. But against the glow of the background galaxy, dark swirling lanes of interstellar dust appear to dominate the face-on spiral's structure. The dust lanes are surprisingly pervasive, and this remarkable pair of overlapping galaxies is one of a small number of systems in which absorption of light from beyond a galaxy's own stars can be used to directly explore its distribution of dust. NGC 3314 is about 140 million light-years (background galaxy) and 117 million light-years (foreground galaxy) away in the multi-headed constellation Hydra. The background galaxy would span nearly 70,000 light-years at its estimated distance. A synthetic third channel was created to construct this dramatic new composite of the overlapping galaxies from two color image data in the Hubble Legacy Archive. May 10, 2012  The rise of the Super Moon was preceded by a Green Flash, captured in the first frame of this timelapse video recorded that night in Brittany, France. The cropped image of the frame, a two second long exposure, shows the strongly colored flash left of the lighted buoy near picture center. While the Super Moon was enjoyed at locations all around the world, the circumstances that produced the Green Flash were more restrictive. Green flashes for both Sun and Moon are caused by atmospheric refraction enhanced by long, low, sight lines and strong atmospheric temperature gradients often favored by a sea horizon. The matching video can be found here, which really gives an impression on how long the green flash lasts.: http://vimeo.com/41670884 May 9, 2012  A lovely starfield in the heroic northern constellation Perseus holds this famous pair of open or galactic star clusters, h and Chi Perseii. Also cataloged as NGC 869 (right) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. Separated by only a few hundred light-years, the clusters' ages based on their individual stars are similar - evidence that they were likely a product of the same star-forming region. Always a rewarding sight in binoculars, the Double Cluster is even visible to the unaided eye from dark locations. Star colors (and spikes) are enhanced in this beautiful, wide field, telescopic image. May 8, 2012  What is that strange blue blob on the far right? No one is sure, but it might be a speeding remnant of a powerful supernova that was unexpectedly lopsided. Scattered debris from supernova explosion N49 lights up the sky in this gorgeous composited image based on data from the Chandra and Hubble Space Telescopes. Glowing visible filaments, shown in yellow, and X-ray hot gas, shown in blue, span about 30 light-years in our neighboring galaxy, the Large Magellanic Cloud. Light from the original exploding star reached Earth thousands of years ago, but N49 also marks the location of another energetic outburst -- an extremely intense blast of gamma-rays detected by satellites about 30 years ago on 1979 March 5. The source of the March 5th Event is now attributed to a magnetar - a highly magnetized, spinning neutron star also born in the ancient stellar explosion which created supernova remnant N49. The magnetar, visible near the top of the image, hurtles through the supernova debris cloud at over 70 thousand kilometers per hour. The blue blob on the far right, however, might have been expelled asymmetrically just as a massive star was exploding. If so, it now appears to be moving over 7 million kilometers per hour. May 7, 2012  It's easy to get lost following the intricate filaments in this detailed mosaic image of faint supernova remnant Simeis 147. Also cataloged as Sh2-240 and seen towards the constellation Taurus, it covers nearly 3 degrees (6 full moons) on the sky. That corresponds to a width of 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years. The remarkable composite includes image data taken through narrow-band filters to highlight emission from hydrogen and oxygen atoms tracing regions of shocked, glowing gas. This supernova remnant has an estimated age of about 40,000 years - meaning light from the massive stellar explosion first reached Earth 40,000 years ago. But this expanding remnant is not the only aftermath. The cosmic catastrophe also left behind a spinning neutron star or pulsar, all that remains of the original star's core. May 6, 2012  In the depths of the dark clouds of dust and molecular gas known as the Omega Nebula, stars continue to form. The above image from the Hubble Space Telescope's Advanced Camera for Surveys shows exquisite detail in the famous star-forming region. The dark dust filaments that lace the center of Omega Nebula were created in the atmospheres of cool giant stars and in the debris from supernova explosions. The red and blue hues arise from glowing gas heated by the radiation of massive nearby stars. The points of light are the young stars themselves, some brighter than 100 Suns. Dark globules mark even younger systems, clouds of gas and dust just now condensing to form stars and planets. The Omega Nebula lies about 5000 light years away toward the constellation of Sagittarius. The region shown spans about 3000 times the diameter of our Solar System. May 5, 2012  Source: Rising as the Sun sets, tonight's Full Moon could be hard to miss. Remarkably, its exact full phase (May 6 03:36 UT) will occur less than two minutes after it reaches perigee, the closest point to Earth in the Moon's orbit, making it the largest Full Moon of 2012. The Full Perigee Moon will appear to be some 14 percent larger and 30 percent brighter than a Full Moon near apogee, the most distant point in the elliptical lunar orbit. In comparison, though, it will appear less than 1 percent larger and almost as bright as April's Full Moon, captured in this telephoto image rising over suburban Fort Collins, Colorado, USA. For that lunation, Full Moon and perigee were about 21 hours apart. Of course, if you manage to miss May's Full Perigee Moon, make a note on your calendar. Your next chance to see a Full Moon close to perigee, will be next year on June 23. May 4, 2012  Source: http://apod.nasa.gov/apod/ap120504.html Exploring the cosmos at extreme energies, the Fermi Gamma-ray Space Telescope orbits planet Earth every 95 minutes. By design, it rocks to the north and then to the south on alternate orbits in order to survey the sky with its Large Area Telescope (LAT). The spacecraft also rolls so that solar panels are kept pointed at the Sun for power, and the axis of its orbit precesses like a top, making a complete rotation once every 54 days. As a result of these multiple cycles the paths of gamma-ray sources trace out complex patterns from the spacecraft's perspective, like this mesmerising plot of the path of the Vela Pulsar. Centered on the LAT instrument's field of view, the plot spans 180 degrees and follows Vela's position from August 2008 through August 2010. The concentration near the center shows that Vela was in the sensitive region of the LAT field during much of that period. Born in the death explosion of a massive star within our Milky Way galaxy, the Vela Pulsar is a neutron star spinning 11 times a second, seen as the brightest persistent source in the gamma-ray sky. May 3, 2012  Source: Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend and colleague Charles Messier as M106. Modern deep telescopic views reveal it to be an island universe: a spiral galaxy around 30 thousand light-years across located only about 21 million light-years beyond the stars of the Milky Way. Along with prominent dust lanes and a bright central core, this colorful composite image highlights youthful blue star clusters and reddish stellar nurseries that trace the galaxy's spiral arms. The high resolution galaxy portrait is a mosaic of data from Hubble's sharp ACS camera combined with groundbased color image data. M106 (aka NGC 4258) is a nearby example of the Seyfert class of active galaxies, seen across the spectrum from radio to X-rays. Energetic active galaxies are powered by matter falling into a massive central black hole. May 2, 2012  Source: How many arches can you count in the above image? If you count both spans of the Double Arch in the Arches National Park in Utah, USA, then two. But since the above image was taken during a clear dark night, it caught a photogenic third arch far in the distance -- that of the overreaching Milky Way Galaxy. Because we are situated in the midst of the spiral Milky Way Galaxy, the band of the central disk appears all around us. The sandstone arches of the Double Arch were formed from the erosion of falling water. The larger arch rises over 30 meters above the surrounding salt bed and spans close to 50 meters across. The dark silhouettes across the image bottom are sandstone monoliths left over from silt-filled crevices in an evaporated 300 million year old salty sea. A dim flow created by light pollution from Moab, Utah can also be seen in the distance. May 1, 2012  Source: On December 24, Comet Lovejoy rose in dawn's twilight, arcing above the eastern horizon, its tails swept back by the solar wind and sunlight. Seen on the left is the comet's early morning appearance alongside the southern Milky Way from the town of Intendente Alvear, La Pampa province, Argentina. The short star trails include bright southern sky stars Alpha and Beta Centauri near the center of the frame, but the long bright streak that crosses the comet tails is a little closer to home. Waiting for the proper moment to start his exposure, the photographer has also caught the International Space Station still glinting in the sunlight as it orbits (top to bottom) above the local horizon. The right panel is the near horizon view of Comet Lovejoy from the space station itself, captured only two days earlier. In fact, Dan Burbank, Expedition 30 commander, recorded Comet Lovejoy rising just before the Sun in a spectacular video (posted below). Even considering the other vistas available from low Earth orbit, Burbank describes the comet as "the most amazing thing I have ever seen in space." http://www.nasa.gov/multimedia/video...a_id=125774121 April 30, 2012  Source: It was all lined up even without the colorful aurora exploding overhead. If you follow the apex line of the recently deployed monuments of Arctic Henge in Raufarhöfn in northern Iceland from this vantage point, you will see that they point due north. A good way to tell is to follow their apex line to the line connecting the end stars of the Big Dipper, Merak and Dubhe, toward Polaris, the bright star near the north spin axis of the Earth projected onto the sky. By design, from this vantage point, this same apex line will also point directly at the midnight sun at its highest point in the sky just during the summer solstice of Earth's northern hemisphere. In other words, the Sun will not set at Arctic Henge during the summer solstice in late June, and at its highest point in the sky it will appear just above the aligned vertices of this modern monument. The above image was taken in late March during a beautiful auroral storm. April 29, 2012  Source: Why does this star have so few heavy elements? Stars born in the generation of our Sun have an expected abundance of elements heavier than hydrogen and helium mixed into their atmospheres. Stars born in the generation before our Sun, Population II stars, the stars that created most of the heavy elements around us today, are seen to have some, although fewer, elements heavier than H and He. Furthermore, even the elusive never-seen first stars in the universe, so-called Population III stars, are predicted to have a large mass and a small but set amount of heavy elements. Yet low-mass Milky Way star SDSS J102915+172927, among others, appears to have fewer metals than ever predicted for any stars, including at least 50 times less lithium than came out of the Big Bang. The unusual nature of this star, initially cataloged by the Sloan Digital Sky Survey (SDSS) and pictured above, was discovered by detailed spectroscopic observations by a large VLT telescope in Chile. Many models of star formation indicate that such a star should not even form. Research is ongoing, however, with one leading hypothesis holding that fragile primordial lithium was destroyed in the star's hot core. April 28, 2012  Source: Last Sunday's bright fireball meteor falling through skies over California and Nevada produced sonic booms over a broad area around 7:51 am. Estimates indicate the meteor was about the size of a minivan. Astronomer Peter Jenniskens subsequently recovered these fragments of a crushed 4 gram meteorite, the second find from this meteor fall, in the parking lot of the Henningsen-Lotus state park, not far from Sutter's Mill. This is now known as the Sutter's Mill Meteorite, the location famous for its association with the California Gold Rush. The meteorite may well be astronomer's gold too, thought to be a rare CM type carbonaceous chondrite, a type rich in organic compounds and similar to the Murchison Meteorite. To trace the meteor's orbit, details of its breakup, and aid in locating more fragements, scientists are also searching for video records. Security cameras across a wide area could have accidently captured the fireball event near 7:51 am PDT on April 22; e.g. California (SF Bay Area, Los Angeles, near Redding) and Nevada (Reno area, Tonopah), even in southern parts of Oregon and near Salt Lake City in Utah. There are some inaccuracies in this video, but it's probably the best one in terms of actually capturing the fireball. April 27, 2012  Source: Planet Earth has many moons. Its largest artifical moon, the International Space Station, streaks through this lovely skyview with clouds in silhouette against the fading light of a sunset. Captured from Stuttgart, Germany last Sunday, the frame also includes Earth's largest natural satellite 1.5 days after its New Moon phase. Just below and left of the young crescent is Jupiter, another bright celestial beacon hovering near the western horizon in early evening skies. Only briefly, as seen from the photographer's location, Jupiter and these moons of Earth formed the remarkably close triple conjunction. Of course, Jupiter has many moons too. In fact, close inspection of the photo will reveal tiny pin pricks of light near the bright planet, large natural satellites of Jupiter known as Galilean moons. April 26, 2012  Source: Last week Mercury wandered far to the west of the Sun. As the solar system's innermost planet neared its greatest elongation or greatest angle from the Sun (for this apparition about 27 degrees) it was joined by an old crescent Moon. The conjunction was an engaging sight for early morning risers in the southern hemisphere. There the pair rose together in predawn skies, climbing high above the horizon along a steeply inclined ecliptic plane. This well composed sequence captures the rising Moon and Mercury above the city lights of Brisbane in Queensland, Australia. A stack of digital images, it consists of an exposure made every 3 minutes beginning at 4:15 am local time on April 19. Mercury's track is at the far right, separated from the Moon's path by about 8 degrees. April 25, 2012  Source: Did you see it? One of the more common questions during a meteor shower occurs because the time it takes for a meteor to flash is typically less than the time it takes for a head to turn. Possibly, though, the glory of seeing bright meteors shoot across and knowing that they were once small pebbles on another world might make it all worthwhile, even if your observing partner(s) could not share in every particular experience. Peaking over the past few days, a dark moonless sky allowed the Lyrids meteor shower to exhibit as many as 30 visible meteors per hour from some locations. A bright Lyrid meteor streaks above picturesque Crater Lake in Oregon, USA, in the above composite of nine exposures taken last week. Snow covers the foreground, while the majestic central band of our home galaxy arches well behind the serene lake. Other meteor showers this year include the Perseids in mid-August and the Leonids in mid-November, both expected to also dodge the glare of a bright Moon in 2012. April 24, 2012  Source: What's causing those odd rings in supernova 1987A? Twenty five years ago, in 1987, the brightest supernova in recent history was seen in the Large Magellanic Cloud. At the center of the above picture is an object central to the remains of the violent stellar explosion. Surrounding the center are curious outer rings appearing as a flattened figure 8. Although large telescopes including the Hubble Space Telescope monitor the curious rings every few years, their origin remains a mystery. Pictured above is a Hubble image of the SN1987A remnant taken last year. Speculation into the cause of the rings includes beamed jets emanating from an otherwise hidden neutron star left over from the supernova, and the interaction of the wind from the progenitor star with gas released before the explosion. April 23, 2012  Source: The unusual blobs found in the Carina nebula, some of which are seen floating on the upper right, might best be described as evaporating. Energetic light and winds from nearby stars are breaking apart the dark dust grains that make the iconic forms opaque. Ironically the blobs, otherwise known as dark molecular clouds, frequently create in their midst the very stars that later destroy them. The floating space mountains pictured above by the orbiting Hubble Space Telescope span a few light months. The Great Nebula in Carina itself spans about 30 light years, lies about 7,500 light years away, and can be seen with a small telescope toward the constellation of Keel (Carina). April 22, 2012  Source: When does Mars act like a liquid? Although liquids freeze and evaporate quickly into the thin atmosphere of Mars, persistent winds may make large sand dunes appear to flow and even drip like a liquid. Visible on the above image right are two flat top mesas in southern Mars when the season was changing from Spring to Summer. A light dome topped hill is also visible on the far left of the image. As winds blow from right to left, flowing sand on and around the hills leaves picturesque streaks. The dark arc-shaped droplets of fine sand are called barchans, and are the interplanetary cousins of similar Earth-based sand forms. Barchans can move intact a downwind and can even appear to pass through each other. When seasons change, winds on Mars can kick up dust and are monitored to see if they escalate into another of Mars' famous planet-scale sand storms. April 21, 2012  Source: These enclosures house 1.8 meter Auxiliary Telescopes (ATs) at Paranal Observatory in the Atacama Desert region of Chile. The ATs are designed to be used for interferometry, a technique for achieving extremely high resolution observations, in concert with the observatory's 8 meter Very Large Telescope units. A total of four ATs are operational, each fitted with a transporter that moves the telescope along a track allowing different arrays with the large unit telescopes. To work as an interferometer, the light from each telescope is then brought to a common focal point by a system of mirrors in underground tunnels. Above these three ATs, the Large and Small Magellanic Clouds are the far far away satellite galaxies of our own Milky Way. In the clear and otherwise dark southern skies, planet Earth's greenish atmospheric airglow stretches faintly along the horizon. April 20, 2012  Source: Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. Its classic appearance is understood to be due to perspective - our view from planet Earth looks down the center of a roughly barrel-shaped cloud of glowing gas. But expansive looping structures are seen to extend far beyond the Ring Nebula's familiar central regions in this intriguing composite of ground based and Hubble Space Telescope images with narrowband image data from Subaru. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from the dying, once sun-like star at the nebula's center. Intense ultraviolet light from the hot central star ionizes atoms in the gas. Ionized oxygen atoms produce the characteristic greenish glow and ionized hydrogen the prominent red emission. The central ring of the Ring Nebula is about one light-year across and 2,000 light-years away. To accompany tonight's shooting stars it shines in the northen constellation Lyra. April 19, 2012  Source: Climbing into cloudy skies, the Space Shuttle Orbiter Discovery (OV-103) took off from Kennedy Space Center Tuesday at 7 am local time. This time, its final departure from KSC, it rode atop a modified Boeing 747 Shuttle Carrier Aircraft. Following a farewell flyover of the Space Coast, Goddard Space Flight Center, and Washington DC, Discovery headed for Dulles International Airport in Virginia, destined to reside at the Smithsonian's National Air and Space Museum Udvar-Hazy Center. Discovery retires as NASA's most traveled shuttle orbiter, covering more than 148 million miles in 39 missions that included the delivery of the Hubble Space Telescope to orbit. Operational from 1984 through 2011, Discovery spent a total of one year in space. April 18, 2012  Source: What would it be like to fly a space shuttle? Although the last of NASA's space shuttles has now been retired, it is still fun to contemplate sitting at the controls of one of the humanity's most sophisticated machines. Pictured above is the flight deck of Space Shuttle Endeavour, the youngest shuttle and the second to last ever launched. The numerous panels and displays allowed the computer-controlled orbiter to enter the top of Earth's atmosphere at greater than the speed of sound and -- just thirty minutes later -- land on a runway like an airplane. The retired space shuttles are now being sent to museums, with Endeavour being sent to California Space Center in Los Angeles, California, Atlantis to the Kennedy Space Center Visitor Complex on Merritt Island, Florida, and Discovery to the Udvar-Hazy Annex of the National Air and Space Museum in Chantilly, Virginia. Therefore sitting in a shuttle pilot's chair and personally contemplating the thrill of human space flight may actually be in your future. April 17, 2012  Source: Antares is a huge star. In a class called red supergiant, Antares is about 850 times the diameter of our own Sun, 15 times more massive, and 10,000 times brighter. Antares is the brightest star in the constellation of Scorpius and one of the brighter stars in all the night sky. Located about 550 light years away, Antares is seen on the left surrounded by a yellowish nebula of gas which it has itself expelled. Radiation from Antares' blue stellar companion helps cause the nebular gas to glow. Far behind Antares, to the lower right in the above image, is the globular star cloud M4, while the bright star on the far right is Al Niyat. April 16, 2012  Source: From afar, the whole thing looks like an Eagle. A closer look at the Eagle Nebula, however, shows the bright region is actually a window into the center of a larger dark shell of dust. Through this window, a brightly-lit workshop appears where a whole open cluster of stars is being formed. In this cavity tall pillars and round globules of dark dust and cold molecular gas remain where stars are still forming. Already visible are several young bright blue stars whose light and winds are burning away and pushing back the remaining filaments and walls of gas and dust. The Eagle emission nebula, tagged M16, lies about 6500 light years away, spans about 20 light-years, and is visible with binoculars toward the constellation of the Serpent (Serpens). This picture combines three specific emitted colors and was taken with the 0.9 meter telescope on Kitt Peak, Arizona, USA. The famous pillars are seen at the centre of this nebula. April 15, 2012  Source: This telescopic close-up shows off the otherwise faint emission nebula IC 410 in striking false-colors. It also features two remarkable inhabitants of the cosmic pond of gas and dust above and left of center, the tadpoles of IC 410. The picture is a composite of images taken through both broad and narrow band filters. The narrow band data traces atoms in the nebula, with emission from sulfur atoms in red, hydrogen atoms in green, and oxygen in blue. Partly obscured by foreground dust, the nebula itself surrounds NGC 1893, a young galactic cluster of stars that energizes the glowing gas. Composed of denser cooler gas and dust the tadpoles are around 10 light-years long, potentially sites of ongoing star formation. Sculpted by wind and radiation from the cluster stars, their tails trail away from the cluster's central region. IC 410 lies some 12,000 light-years away, toward the constellation Auriga. April 14, 2012  Source: How many moons does Saturn have? So far 62 have been discovered, the smallest only a fraction of a kilometer across. Six of its largest satellites can be seen here, though, in a sharp Saturnian family portrait taken on March 9. Larger than Earth's Moon and even slightly larger than Mercury, Titan has a diameter of 5,150 kilometers and starts the line-up at the lower left. Continuing to the right across the frame are Mimas, Tethys, [Saturn], Enceladus, Dione, and Rhea at far right. Saturn's first known natural satellite, Titan was discovered in 1655 by Dutch astronomer Christiaan Huygens, while most recently the satellite provisionally designated S/2009 S1 was found by the Cassini Imaging Science Team in 2009. Tonight, Saturn reaches opposition in planet Earth's sky, offering the best telescopic views of the ringed planet and moons. April 13, 2012  Source: Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light. The brightness of the nebula is determined by the size and density of the reflecting grains, and by the color and brightness of the neighboring star(s). NGC 1435, pictured above, surrounds Merope (23 Tau), one of the brightest stars in the Pleiades (M45). The Pleiades nebulosity is caused by a chance encounter between an open cluster of stars and a dusty molecular cloud. April 12, 2012  Source: On another April 12th, in 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human to see planet Earth from space. Commenting on his view from orbit he reported, "The sky is very dark; the Earth is bluish. Everything is seen very clearly". To celebrate, consider this recent image from the orbiting International Space Station. A stunning view of the planet at night from an altitude of 240 miles, it was recorded on March 28. The lights of Moscow, Russia are near picture center and one of the station's solar panel arrays is on the left. Aurora and the glare of sunlight lie along the planet's gently curving horizon. Stars above the horizon include the compact Pleiades star cluster, immersed in the auroral glow. The effect of light pollution is shown in this photo as brown-yellow light domes are clearly visible. April 11, 2012  Source: Why would Venus appear oval? Venus has been seen countless times from the surface of the Earth, and every time the Earth's atmosphere has dispersed its light to some degree. When the air has just the right amount of dust or water droplets, small but distant objects like Venus appear spread out into an angularly large aureole. Aureoles are not unusual to see and are frequently noted as circular coronas around the Sun or Moon. Recently, however, aureoles have been imaged that are not circular but distinctly oval. The above oval Venusian aureole was imaged by the astrophotographer who first noted the unusual phenomenon three years ago. Initially disputed, the unusual distortion has now been confirmed multiple times by several different astrophotographers. What causes the ellipticity is currently unknown, and although several hypotheses hold that horizontally oriented ice crystals are responsible, significant discussions about it are still taking place. April 10, 2012  Source: Does part of this image look familiar? In the second picture in as many days, the Cone Nebula is revisited with its many friends in a more zoomed out scale. Found in Monoceros, pictured above is a star forming region cataloged as NGC 2264, the complex jumble of cosmic gas and dust is about 2,700 light-years distant and mixes reddish emission nebulae excited by energetic light from newborn stars with dark interstellar dust clouds. Where the otherwise obscuring dust clouds lie close to the hot, young stars they also reflect starlight, forming blue reflection nebulae. The above image spans about 3/4 degree or nearly 1.5 full moons, covering 40 light-years at the distance of NGC 2264. Its cast of cosmic characters includes the Fox Fur Nebula, whose convoluted pelt lies at the upper left, bright variable star S Mon immersed in the blue-tinted haze just below the Fox Fur, and the Cone Nebula near the tree's top. Of course, the stars of NGC 2264 are also known as the Christmas Tree star cluster. The triangular tree shape traced by the stars appears sideways here, with its apex at the Cone Nebula and its broader base centered near S Mon. April 9, 2012  Source: Strange shapes and textures can be found in neighborhood of the Cone Nebula. The unusual shapes originate from fine interstellar dust reacting in complex ways with the energetic light and hot gas being expelled by the young stars. The brightest star on the right of the above picture is S Mon, while the region just below it has been nicknamed the Fox Fur Nebula for its color and structure. The blue glow directly surrounding S Mon results from reflection, where neighboring dust reflects light from the bright star. The red glow that encompasses the whole region results not only from dust reflection but also emission from hydrogen gas ionized by starlight. S Mon is part of a young open cluster of stars named NGC 2264, located about 2500 light years away toward the constellation of the Unicorn (Monoceros). The origin of the mysterious geometric Cone Nebula, visible on the far left, remains a mystery. April 8, 2012  Source: Hurtling through a cosmic dust cloud some 400 light-years away, the lovely Pleiades or Seven Sisters star cluster is well-known for its striking blue reflection nebulae. In the dusty sky toward the constellation Taurus and the Orion Arm of our Milky Way Galaxy, this remarkable image shows the famous star cluster at the upper left. But lesser known dusty nebulae lie along the region's fertile molecular cloud, within the 10 degree wide field, including the bird-like visage of LBN 777 near center. Small bluish reflection nebula VdB 27 at the lower right is associated with the young, variable star RY Tau. At the distance of the Pleiades, the 5 panel mosaic spans nearly 70 light-years. The dust clouds are seen as brown clouds, not to be confused with clouds that might be seen in terrestrial levels. April 7, 2012  Source: The star near the top is so bright that it is sometimes hard to notice the galaxy toward the bottom. Pictured above, both the star, Regulus, and the galaxy, Leo I, can be found within one degree of each other toward the constellation of the Lion (Leo). Regulus is part of a multiple star system, with a close companion double star visible to the lower left of the young main sequence star. Leo I is a dwarf spheroidal galaxy in the Local Group of galaxies dominated by our Milky Way Galaxy and M31. Leo I is thought to be the most distant of the several known small satellite galaxies orbiting our Milky Way Galaxy. Regulus is located about 75 light years away, in contrast to Leo 1 which is located about 800,000 light years away. Regulus is easy to spot these days as it is accompanied by Mars after sunset and hangs around until the early morning hours. April 6, 2012  Source: After wandering about as far from the Sun on the sky as Venus can get, the brilliant evening star crossed paths with the Pleiades star cluster earlier this week. The beautiful conjunction was enjoyed by skygazers around the world. Taken on April 2, this celestial group photo captures the view from Portal, Arizona, USA. Also known as the Seven Sisters, even the brighter naked-eye Pleiades stars are seen to be much fainter than Venus. And while Venus and the sisters do look star-crossed, their spiky appearance is the diffraction pattern caused by multiple leaves in the aperture of the telephoto lens. The last similar conjunction of Venus and Pleiades occurred nearly 8 years ago. As it did then, Venus will again move on to cross paths with the disk of the Sun in June. It is the last time in our lifetime that it will do so. Unless you plan to live through the late 22nd century. April 5, 2012  Source: Sweeping from the eastern to western horizon, this 360 degree panorama follows the band of zodiacal light along the solar system's ecliptic plane. Dust scattering sunlight produces the faint zodiacal glow that spans this fundamental coordinate plane of the celestial sphere, corresponding to the apparent yearly path of the Sun through the sky and the plane of Earth's orbit. The fascinating panorama is a mosaic of images taken from dusk to dawn over the course of a single night at two different locations on Mauna Kea. The lights of Hilo, Hawaii are on the eastern (left) horizon, with the Subaru and twin Keck telescope structures near the western horizon. On that well chosen moonless night, Venus was shining as the morning star just above the eastern horizon, and Saturn was close to opposition. In fact, Saturn is seen immersed in a brightening of the zodiacal band known as the gegenschein. The gegenschein also lies near 180 degrees in elongation or angular distance from the Sun along the ecliptic. In the mosaic projection, the plane of our Milky Way Galaxy runs at an angle, crossing the horizontal band of zodiacal light above the two horizons. Nebulae, stars, and dust clouds of the bulging galactic center are rising in the east. April 4, 2012  Source: What's the closest active galaxy to planet Earth? That would be Centaurus A, only 11 million light-years distant. Spanning over 60,000 light-years, the peculiar elliptical galaxy is also known as NGC 5128. Forged in a collision of two otherwise normal galaxies, Centaurus A's fantastic jumble of young blue star clusters, pinkish star forming regions, and imposing dark dust lanes are seen here in remarkable detail. The colorful galaxy portrait was recorded under clear Chilean skies at the Cerro Tololo Inter-American Observatory. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. That process likely generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A. April 3, 2012  Source: Many stars form in clusters. Galactic or open star clusters are relatively young swarms of bright stars born together near the plane of our Milky Way Galaxy. Separated by about a degree on the sky, two nice examples are M46 (upper left) 5,400 light-years in the distance and M47 (lower right) only 1,600 light-years away toward the nautical constellation Puppis. Around 300 million years young M46 contains a few hundred stars in a region about 30 light-years across. Aged 80 million years, M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. But this portrait of stellar youth also contains an ancient interloper. The small, colorful patch of glowing gas in M46 of the same colour is actually the planetary nebula NGC 2438 - the final phase in the life of a sun-like star billions of years old. It is found near the bottom of M46 within our line of sight to the cluster. NGC 2438 is estimated to be only 3,000 light-years distant and likely represents a foreground object, only by chance appearing along our line of sight to youthful M46. April 2, 2012  Source: What's large and blue and can wrap itself around an entire galaxy? A gravitational lens mirage. Pictured above, the gravity of a luminous red galaxy (LRG) has gravitationally distorted the light from a much more distant blue galaxy. More typically, such light bending results in two discernible images of the distant galaxy, but here the lens alignment is so precise that the background galaxy is distorted into a horseshoe -- a nearly complete ring. Since such a lensing effect was generally predicted in some detail by Albert Einstein over 70 years ago, rings like this are now known as Einstein Rings. Although LRG 3-757 was discovered in 2007 in data from the Sloan Digital Sky Survey (SDSS), the image shown above is a follow-up observation taken with the Hubble Space Telescope's Wide Field Camera 3. Strong gravitational lenses like LRG 3-757 are more than oddities -- their multiple properties allow astronomers to determine the mass and dark matter content of the foreground galaxy lenses. April 1, 2012  Source: This rugged road through the dark Atacama Desert seems to lead skyward toward the bright stars and glowing nebulae of the southern Milky Way. If you follow the road you will get to Cerro Armazones peak in Chile, future construction site for the 40-meter class European Extremely Large Telescope. For now though, sliding your cursor across the image will identify wonders of the southern skies in view. The scene is dominated by the reddish glow of the Great Carina Nebula, one of our galaxy's largest star forming regions. In fact, the remarkable skyscape is not a composite of varying exposures or a photomontage. Far from sources of light pollution, the landscape illuminated by starlight and the Milky Way above were recorded by a modified digital camera and fast lens. The sensitive system captured both planet Earth and deep sky in a relatively short exposure. March 31, 2012  Source: Meet M9. M9 is a globular cluster discovered by Charles Messier, and listed it as the 9th entry in his catalogue (hence Messier 9). He listed this globular cluster as a "Nebula, without star, in the right leg of Ophiuchus ...". Optics have improved since the 18th century however, and this 'starless nebula' has been found to contain over 300,000 stars within a diameter of 90 light years. It is some 25,000 light years distant near the central bulge of our milky way galaxy. This picture takes a look at the central 25 light years of the cluster. At least twice the age of the Sun and deficient in heavy elements, the cluster stars have colors corresponding to their temperatures, redder stars are cooler, bluer stars are hotter. Many of the cluster's cool red giant stars show a yellowish tint in the sharp Hubble view. Globular clusters are typically found -outside- the disk of spiral galaxies, and are evidence that a spiral galaxy was once more spherical in shape before flattening into a disk with a bulge. March 30, 2012  Source: In this alluring night skyscape recorded on March 26, a young Moon stands over the distant western horizon in conjunction with brilliant planet Venus. In the foreground, the Colorado River glistens in moonlight as it winds through the Grand Canyon, seen from the canyon's southern rim at Lipan Point. The Grand Canyon is known as one of the wonders of planet Earth. Carved by the river, the enormous fissure is about 270 miles (440 kilometers) long, up to 18 miles (30 kilometers) wide and approaches 1 mile (1.6 kilometers) deep. On this date, wonders of the night sky included the compact Pleiades and V-shaped Hyades star clusters poised just above the Moon. Bright planet Jupiter is below the closer Moon/Venus pairing, near the western horizon. March 29, 2012  Source: On March 27, five sounding rockets leapt into early morning skies from NASA's Wallops Flight Facility in Virginia. Part of the Anomalous Transport Rocket EXperiment (ATREX), begining at 4:58 am EDT the rockets launched consecutively at 80 second intervals. Releasing a chemical tracer they created luminous white clouds within Earth's ionosphere at altitudes above 60 to 65 miles, swept along by the poorly understood high-altitude jet stream. (Not the same jet stream that airliners fly through at altitudes of 5 to 6 miles.) Seen along the mid-atlantic region of the United States, the clouds drifted through starry skies, captured in this clear photograph from East Point, New Jersey. Looking south toward the launch site, the tantalizing celestial background includes the stars of Sagittarius, Scorpius, and the more permanent faint, white, luminous clouds of the Milky Way. Can you distinguish these constellations? March 28, 2012  Source: Taken in Madrid, Spain, this photograph taken just yesterday shows significant earthshine from the Moon, and the bright planet Venus. Earthshine is the illumination of the part of the Moon hidden from direct sunlight by the sun-reflecting Earth. During the thin crescent moon stages, around sunset and sunrise, the Earth is reflective enough to illuminate the surface of the moon that is not being hit by direct sunlight. This moon-venus pair could have been seen around the world, weather permitting. March 27, 2012  Source: How do stars form? To help study this complex issue, astronomers took a deep infrared image of Cygnus X, the largest known star forming region in the entire Milky Way Galaxy. The above recently-released image was taken in 2009 by the orbiting Spitzer Space Telescope and digitally translated into colors humans can see, with the hottest regions colored the most blue. Visible are large bubbles of hot gas inflated by the winds of massive stars soon after they form. Current models posit that these expanding bubbles sweep up gas and sometimes even collide, frequently creating regions dense enough to gravitationally collapse into yet more stars. The star factory Cygnus-X spans over 600 light years, contains over a million times the mass of our Sun, and shines prominently on wide angle infrared panoramas of the night sky. Cygnus X lies 4,500 light years away towards the constellation of the Swan (Cygnus). In a few million years, calm will likely be restored and a large open cluster of stars will remain - which itself will disperse over the next 100 million years. March 26, 2012  Source: Saturn is best well known as the planet with the most obvious rings. The rings however, also form one of the largest known sundials. These sundials determine season, not day. During Saturn's last equinox in 2009, there were almost no ring shadows cast onto Saturn, since the ring plane pointed directly to the sun. Since 2009, these shadows have become ever wider and are being cast further south. We cannot easily see these shadows because from our vantage point, the rings always block the shadows. This image was taken by the Cassini spacecraft currently orbiting Saturn. The actual rings appear as the solid vertical bar on the right, while the shadows of the rings are the complex darker shades along the planet. Cassini will orbit Saturn until 2017 when the shadows reach maximum elongation. March 25, 2012  Source: NGC 1300 is a Barred Spiral Galaxy that is 70 million light years away from Earth in the constellation of Eridanus. This is one of the largest hubble images ever made of a complete galaxy. It spans 100,000 light years and there are interesting details of the central bar and majestic arms. For example, the hubble image reveals that inside this Sb (Barred Spiral) galaxy lies another spiral of some sort that is some 3,000 light years across. It is believed that there is no black hole in the centre of this galaxy unlike the milky way, and many other galaxies which do have a supermassive black hole. Our own galaxy is also believed to be a barred spiral galaxy.  March 24, 2012  Source: Today's photo is a little closer to home, and if you follow today's sky you will be able to see this for yourself. Shown here is the "new side of the moon" and the "old side of the moon". There are certain phases of the cycle where both are very visible to the human eye. Today is one of those phases, and the 'dark moon' is visible because of "ashen glow". Ashen Glow is the word used to describe the earthshine that reflects off the moon. The popular crescent is reflected through the sun, and the remainder of the moon is reflected through the Earth. It is known to be strongly influenced by cloud cover, and descriptions of Earthshine have been documented 500+ years ago by Leonardo da Vinci. In this phase, if one was on the moon and looking at Earth, a very bright, nearly full Earth would be seen from the surface. March 23, 2012  Source: In this photo, the eye is drawn towards NGC 7635, or the Bubble Nebula. Closely neighbouring the Bubble nebula is M52, an open star cluster. The Bubble nebula is only 10 light years wide, while the cluster is about 25 light years wide containing approximately 1,000 stars. This space in the sky spans 1.5 degrees, or about the size of 3 full moons side by side. They can be found on the northern boundary of the constellation Cassiopeia in the Northern Hemisphere. The Bubble Nebula has a magnitude of +10, while the cluster has a magnitude of +5.0. Use a telescope to find them both! March 22, 2012  Source: Meet the Helix Nebula. It is found in the constellation Aquarius and is only 700 light years away. A few thousand years ago, this used to be a regular star such as our sun. However, it ran out of hydrogen and helium to fuse during the red giant phase and as such, it released everything but its core into this brilliant nebula. The remains of the original star is the core called a "White Dwarf" found in the centre of the nebula. It will slowly fade because there is no nuclear reaction burning inside the star, it's the equivalent of a stovetop the moment you turn it off after leaving it on high heat for an hour. You know not to touch the stovetop immediately after turning it off because it's still hot - so to is the star, not a good idea to touch it. This is NOT a supernova explosion, but rather, this is the type of remnant that 95% of stars will leave behind, including our sun. This remnant cloud is where future stars are born. March 21, 2012   Source: Star parties are one of the best ways to explore the deep night sky. Red light is used to ensure that night vision is not ruined, as to see the contents of this image requires 20 minutes of absolute darkness, and only red light seems to keep that vision. This particular photo was taken during the 10th annual Iran Messier Marathon in April 2011. A Messier Marathon is completed when one views all 110 of the messier catalogue in one night. The stars rise and set fast, especially when you're searching for 110 different objects, some of which only being visible for about 20 minutes before they set! How many Messier objects do YOU see? hint: the green laser points to M8. March 20, 2012  Source: Does this look strange to you? Well it sure does to just about everyone who knows of it in the world of astronomy. This is MWC 922, nicknamed "The Red Square Nebula", found in the constellation Serpens. Only those relatively near the equator will be able to get a good view of this constellation, as the north and south hemispheres only ever see it near the horizon. What causes the nebula to be square? The answer to this one is that we don't know. It is thought that it only looks like a square through our spective. The star behind the nebula is a Be (very hot classification star, OBAFGKM being the hottest, M coldest) star that is losing mass in a bipolar outflow. It is spewing gas in a pair of conical outflows, This, combined with a ring of material that shields the rest of the projection, is the main theory on to how this square nebula exists. March 19, 2012   Source: Have you ever heard of the zodiacal light? If you're in a completely dark area, just before the sun begins to rise, look towards the Milky Way belt. The Milky Way will have its own fair share of light beaming towards you; a culmination of the billions of stars found in the belt of our galaxy. You should also begin to notice a faint light that shoots away from the galaxy centre - this is the zodiacal light. Appearing only before sunrise or after sunset, this glow is sunlight reflected by billions of tiny dust particles orbiting in the Solar System. Many of these particles are pieces of asteroid and comet that have since broken away from their main body. This image was taken in Ras Lanuf, Libya. Use the annotated version to help you learn a bit about the sky! Challenge: Can YOU spot the faint red North America nebula just north west of Deneb in Cygnus? March 18, 2012 Source: Meet the Perseus-Pisces supercluster of galaxies. Spanning more than 40 degrees across the northern winter sky, it is one of the largest known structures in the universe. It ranges from the Perseus constellation to the Pisces constellation, which can't be viewed at at this time because that is the constellation that the sun is currently in. Perseus however, is quite visible after sunset. There are 141 galaxies found in this structure, and is roughly 250 million light years away. When looking through a telescope, each one of these galaxies may appear as a fuzzy blob. This image view covers about 15 million light years across the supercluster. March 17, 2012 Source: This photo is part of the spiral galaxy M83, which is 12 million light years away. It can be found near the bottom of constellation Hydra, and this galaxy is known for it's prominent blue star clusters and red star clusters found in its arms. These clusters have given M83 the nickname of "The Thousand-Ruby Galaxy," but it is more often referred to as the Southern Pinwheel. The centre of this galaxy is dominated by red, older stars so it appears yellow. The blue and red clusters are areas of starbirth, where the blue stars are hot, young, bright and brilliant, and the red clusters are filled with ionized hydrogen, creating new stars. March 16, 2012 Source: One of the most famous images related to space as of late, this is a photo of the Pillars of Creation taken in 1995 by the Hubble Telescope. The pillars lie in the Eagle Nebula dubbed M16 and are associated with an open star cluster. The "pillars" are molecular hydrogen gas and dark dust that doesn't emit light. The pillars are light years in length and so dense that interior gas actually gravitationally contracts to form stars. Unfortunately, this pretty structure is short lived, as there is evidence of a supernova explosion that happened 6,000 years ago. The Eagle Nebula and the Pillars of Creation are about 7,000 light years away, so we only have another thousand years to observe these pillars before we witness their destruction. March 15, 2012 Source: The heart and soul nebulae are located in Cassiopeia, a familiar constellation in North America due to it's 5 obvious bright stars that are often said to look like a W. The nebulae shine brightly with the red light of energized hydrogen. There are several young star clusters visible in this image as well, appearing in blue, which makes this area a hot spot for astrophotography. Andromeda Galaxy isn't too far away from this picture either. A hydrogen filter on a camera would bring out the nebulae nicely if one wished to take a picture of these emission nebulae. March 14, 2012 Source: This is a digitally stacked series of Mars to track the movement of Mars between October and June. Between this time, Mars appears to move backwards. Approximately every 2 years, Earth passes Mars as they orbit around the Sun. During the pass, Mars appears brightest, and also looks to move backwards in the sky. This is called retrograde motion. At the centre of this loop that Mars makes, retrograde motion is at its highest. March 13, 2012  Source: Under a completely dark sky in the southern hemisphere, if you went outside and tilted your head up while the sky was clear, this is what you would see after letting your eyes adjust for about 20 minutes to the faint lights the Milky Way galaxy has to offer. This picture specifically was taken on Mangaia, the southernmost of the Cook islands. The bright stars just off centre to the right are part of the constellation Centaurus. The brightest star is alpha centauri, which follows how stars are typically named. They are named from brightest to dimmest, beginning with the greek alphabet, and often extending into our alphabet. For example, "beta sagittae" is the 2nd brightest star in the constellation Sagittarius. March 12, 2012  Source: Ever wonder what the night sky would look like if you took a 4 hour long exopsure with your camera? You'd notice the stars generate neat star trails of how they've progressed over the course of 4 hours. They revolve around the north and south poles in this 360 degree panorama taken in Mudgee, New South Wales, Austrailia. March 11, 2012 Source: Comet Garradd within 1 degree of M92, a globular cluster found in Hercules. It approaches the best time for viewing this month. March 10, 2012
 Source: Visible in the northern hemisphere, M45, or Pleiades, or the Seven Sisters is a cluster of blue stars - the 7 brightest can be seen with the naked eye even in a light polluted city. How do you find it? Use the belt of Orion, which nicely points straight at the Pleiades (this picture is upside down):  |
Re: Terry's Astronomy Thread.
What's in the Sky Tonight?
March 19, 2012 -Spring begins in the northern hemisphere tonight at 1:14am Tuesday EST, 10:14pm Monday PST when the sun crosses the equator on its way north. Now the sun rises and sets almost due east and west, and day and night are equally long. Autumn begins in the Southern Hemisphere. -In the northern hemisphere, look northwest for the W-shaped constellation Cassiopeia, now standing on its end. Astro Picture of the Day March 19, 2012 Source: Have you ever heard of the zodiacal light? If you're in a completely dark area, just before the sun begins to rise, look towards the Milky Way belt. The Milky Way will have its own fair share of light beaming towards you; a culmination of the billions of stars found in the belt of our galaxy. You should also begin to notice a faint light that shoots away from the galaxy centre - this is the zodiacal light. Appearing only before sunrise or after sunset, this glow is sunlight reflected by billions of tiny dust particles orbiting in the Solar System. Many of these particles are pieces of asteroid and comet that have since broken away from their main body. This image was taken in Ras Lanuf, Libya. Use the annotated version to help you learn a bit about the sky! Challenge: Can YOU spot the faint red North America nebula just north west of Deneb in Cygnus? |
Re: Terry's Astronomy Thread.
Yay spring has officially begun! ^^ I want to get involved in an astronomy course in school, but for my board it is only available in Grade 12 in my school, and I'm in Grade 10 right now.
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Re: Terry's Astronomy Thread.
It's great that this thread is encouraging people to learn more about astronomy, thanks Winrar and Gold Stinger for the feedback :D Maybe I'll be able to teach you guys something before you enter your courses. In my high school, it was but a subchapter in grade 9 science but I found it to be the most interesting out of any science course I took.
What's in the Sky Tonight? March 20, 2012 -This is the time of year when the dim Little Dipper juts to the right from Polaris (found in the constellation's its handle end) during evening hours. The much brighter Big Dipper curls over high above it, "dumping water" into it. -This is also the time of year when Orion declines in the southwest after dark with his Belt roughly horizontal. But when does Orion's Belt appear exactly horizontal? That depends on where you're located east-west in your time zone, and on your latitude. How accurately can you time this event at your location? Orion's Belt is slightly curved, so judge by the two stars on its ends. Can you rig up a sighting reference to make your measurement more precise? Welcome to pre-telescopic astronomy! Astro Picture of the Day March 20, 2012 Source: Does this look strange to you? Well it sure does to just about everyone who knows of it in the world of astronomy. This is MWC 922, nicknamed "The Red Square Nebula", found in the constellation Serpens. Only those relatively near the equator will be able to get a good view of this constellation, as the north and south hemispheres only ever see it near the horizon. What causes the nebula to be square? The answer to this one is that we don't know. It is thought that it only looks like a square through our spective. The star behind the nebula is a Be (very hot classification star, OBAFGKM being the hottest, M coldest) star that is losing mass in a bipolar outflow. It is spewing gas in a pair of conical outflows, This, combined with a ring of material that shields the rest of the projection, is the main theory on to how this square nebula exists. |
Re: Terry's Astronomy Thread.
What's in the Sky Tonight?
March 21, 2012 -The moon is out of the sky long enough to do some serious deep sky hunting. Have you heard of the messier objects? Messier was a comet hunter who generated a list of objects that were -not- comets, and passed this list on to other comet hunters. This list generated 110 objects, and is mostly galaxies, with a fair amount of star clusters. Some nebulae exist too. Refer to here for the complete list of Messier's catalogue. Astro Picture of the Day March 21, 2012 Source: Star parties are one of the best ways to explore the deep night sky. Red light is used to ensure that night vision is not ruined, as to see the contents of this image requires 20 minutes of absolute darkness, and only red light seems to keep that vision. This particular photo was taken during the 10th annual Iran Messier Marathon in April 2011. A Messier Marathon is completed when one views all 110 of the messier catalogue in one night. The stars rise and set fast, especially when you're searching for 110 different objects, some of which only being visible for about 20 minutes before they set! How many Messier objects do YOU see? hint: the green laser points to M8. |
Re: Terry's Astronomy Thread.
Ophiuchus... The dog with the backwards head
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Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 22, 2012 -Our familiar Venus and Jupiter scene in the west has now shifted into a vertical pillar. Venus is 6 degrees directly above Jupiter (there may be slight variance depending on your location.) -New Moon (exact at 10:37 a.m. EDT). http://uvs-model.com/pictures/nebula_helix_large.jpg Astro Picture of the Day: March 22, 2012 Source: Meet the Helix Nebula. It is found in the constellation Aquarius and is only 700 light years away. A few thousand years ago, this used to be a regular star such as our sun. However, it ran out of hydrogen and helium to fuse during the red giant phase and as such, it released everything but its core into this brilliant nebula. The remains of the original star is the core called a "White Dwarf" found in the centre of the nebula. It will slowly fade because there is no nuclear reaction burning inside the star, it's the equivalent of a stovetop the moment you turn it off after leaving it on high heat for an hour. You know not to touch the stovetop immediately after turning it off because it's still hot - so to is the star, not a good idea to touch it. This is NOT a supernova explosion, but rather, this is the type of remnant that 95% of stars will leave behind, including our sun. This remnant cloud is where future stars are born. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 23, 2012 -Look low in the west about a half hour after sunset, below Venus and Jupiter and perhaps a little right, for the very thin crescent Moon in the bright twilight — as shown at bottom-right here. Astro Picture of the Day: March 23, 2012 Source: In this photo, the eye is drawn towards NGC 7635, or the Bubble Nebula. Closely neighbouring the Bubble nebula is M52, an open star cluster. The Bubble nebula is only 10 light years wide, while the cluster is about 25 light years wide containing approximately 1,000 stars. This space in the sky spans 1.5 degrees, or about the size of 3 full moons side by side. They can be found on the northern boundary of the constellation Cassiopeia in the Northern Hemisphere. The Bubble Nebula has a magnitude of +10, while the cluster has a magnitude of +5.0. Use a telescope to find them both! |
Re: Terry's Astronomy Thread.
Fascinating. :)
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Re: Terry's Astronomy Thread.
This is really cool to read every time you update!
I appreciate it. |
Re: Terry's Astronomy Thread.
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Re: Terry's Astronomy Thread.
Awesome thread :) Always been interested in the night sky.
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Re: Terry's Astronomy Thread.
Thanks for the support guys :D Always nice to know there are people who regularly follow the thread.
What's in the sky tonight? March 24, 2012 -In order from highest to lowest, Venus, Jupiter, and the thin crescent moon form a bent line in the west and are evenly spread apart tonight. -As darkness deepens, look for the Pleiades (M45) just above Venus. The bent line points to them! Astro Picture of the Day: March 24, 2012 Source: Today's photo is a little closer to home, and if you follow today's sky you will be able to see this for yourself. Shown here is the "new side of the moon" and the "old side of the moon". There are certain phases of the cycle where both are very visible to the human eye. Today is one of those phases, and the 'dark moon' is visible because of "ashen glow". Ashen Glow is the word used to describe the earthshine that reflects off the moon. The popular crescent is reflected through the sun, and the remainder of the moon is reflected through the Earth. It is known to be strongly influenced by cloud cover, and descriptions of Earthshine have been documented 500+ years ago by Leonardo da Vinci. In this phase, if one was on the moon and looking at Earth, a very bright, nearly full Earth would be seen from the surface. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 25, 2012 -The moon visits Jupiter today in the west this evening. Make sure you get a good look tonight, because you won't see Jupiter and the Moon this close again until April 22, but then there will be a much thinner moon, and an ever fainter Jupiter buried deep in bright twilight. It will be several months before such a pairing is seen after that. Use this chart to find Jupiter before the sun sets! Astro Picture of the Day: March 25, 2012 Source: NGC 1300 is a Barred Spiral Galaxy that is 70 million light years away from Earth in the constellation of Eridanus. This is one of the largest hubble images ever made of a complete galaxy. It spans 100,000 light years and there are interesting details of the central bar and majestic arms. For example, the hubble image reveals that inside this Sb (Barred Spiral) galaxy lies another spiral of some sort that is some 3,000 light years across. It is believed that there is no black hole in the centre of this galaxy unlike the milky way, and many other galaxies which do have a supermassive black hole. Our own galaxy is also believed to be a barred spiral galaxy. |
Re: Terry's Astronomy Thread.
The pictures of the Red Square Nebula and the Earthshine are really impressive. Looking forward for more posts.
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Re: Terry's Astronomy Thread.
best thread for sure 2k12.
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Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 26, 2012 -If you missed yesterday's Jupiter-moon pair, don't worry, there is one more chance tonight. This time, the Moon-Venus pair will dominate the night sky, with the Moon being on the left hand side of the pair. In reality, Venus is 260 times farther away from us than the Moon. Venus is at its greatest elongation, 46 degrees east of the Sun, making this the best time to spot Venus during daylight hours. How early can YOU spot Venus? I have been able to as early as 80 minutes before sunset. Astro Picture of the Day: March 26, 2012 Source: Saturn is best well known as the planet with the most obvious rings. The rings however, also form one of the largest known sundials. These sundials determine season, not day. During Saturn's last equinox in 2009, there were almost no ring shadows cast onto Saturn, since the ring plane pointed directly to the sun. Since 2009, these shadows have become ever wider and are being cast further south. We cannot easily see these shadows because from our vantage point, the rings always block the shadows. This image was taken by the Cassini spacecraft currently orbiting Saturn. The actual rings appear as the solid vertical bar on the right, while the shadows of the rings are the complex darker shades along the planet. Cassini will orbit Saturn until 2017 when the shadows reach maximum elongation. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 27, 2012 -As night comes on, look for the little Pleiades cluster to the lower right of the Moon and above Venus. Left of the Moon shines orange Aldebaran, with the stars of the Hyades around it. -Early Wednesday morning, along a path from New Mexico to central California, the 6.8-magnitude star 14 Virginis will be occulted low in the west-southwestern sky by the small asteroid 823 Sisigambis. The star should vanish for no more than 1.6 seconds within several minutes of 11:23 Universal Time. Astro Picture of the Day March 27, 2012 Source: How do stars form? To help study this complex issue, astronomers took a deep infrared image of Cygnus X, the largest known star forming region in the entire Milky Way Galaxy. The above recently-released image was taken in 2009 by the orbiting Spitzer Space Telescope and digitally translated into colors humans can see, with the hottest regions colored the most blue. Visible are large bubbles of hot gas inflated by the winds of massive stars soon after they form. Current models posit that these expanding bubbles sweep up gas and sometimes even collide, frequently creating regions dense enough to gravitationally collapse into yet more stars. The star factory Cygnus-X spans over 600 light years, contains over a million times the mass of our Sun, and shines prominently on wide angle infrared panoramas of the night sky. Cygnus X lies 4,500 light years away towards the constellation of the Swan (Cygnus). In a few million years, calm will likely be restored and a large open cluster of stars will remain -- which itself will disperse over the next 100 million years. |
Re: Terry's Astronomy Thread.
Wow, cannot believe how beautifull the nightsky can be.
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Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 28, 2012 -Do you have a pair of binoculars? Are you familiar with them? Today we turn our attention to the constellation of Cancer, where the relatively subtle constellation secretly has a few hidden treasures. The most obvious of them is M44, the Beehive Cluster. M67 is a fainter cluster a little further south of Cancer, and Iota Cancri, in my opinion the toughest of the 3 to distinguish, is a double star of 2 stars with similar brightness. It is difficult because they are two stars, 4th and 6th magnitude, that are very close together from our vantage point and may be difficult to distinguish from. -The eclipsing variable star Algol should be at minimum light, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 9:00 p.m. EDT. Astro Picture of the Day March 28, 2012 Source: Taken in Madrid, Spain, this photograph taken just yesterday shows significant earthshine from the Moon, and the bright planet Venus. Earthshine is the illumination of the part of the Moon hidden from direct sunlight by the sun-reflecting Earth. During the thin crescent moon stages, around sunset and sunrise, the Earth is reflective enough to illuminate the surface of the moon that is not being hit by direct sunlight. This moon-venus pair could have been seen around the world, weather permitting. ---- What's in the Sky Tonight Archive September 1, 2012 - February 28, 2013 February 28, 2013 -Look for Spica very close to the waning gibbous Moon late this evening, as seen from North America. The Moon occults (hides) Spica for viewers from southeastern Mexico through central South America.   February 27, 2013 -The seasons are turning; by 8 or 9 p.m. the Big Dipper has climbed as high in the northeast as Cassiopeia has sunk in the northwest. -Keep an eye out tomorrow for the moon's close encounter with Spica - if you live in the South American regions the moon actully occults Spica. February 26, 2013 -With spring less than a month away, Orion is starting to tip over toward the southwest fairly early in the evening now. February 25, 2013  Sometimes the Moon is a busy direction. Last week, for example, our very Moon passed in front of the planet Jupiter. While capturing this unusual spectacle from New South Wales, Australia, a quick-thinking astrophotographer realized that a nearby plane might itself pass in front of the Moon, and so quickly reset his camera to take a continuous series of short duration shots. As hoped, for a brief instant, that airplane, the Moon, and Jupiter were all visible in a single exposure, which is shown above. But the project was not complete - a longer exposure was then taken to bring up three of the Jupiter's own moons: Io, Calisto, and Europa (from left to right). Unfortunately, this triple spectacle soon disappeared. Less than a second later, the plane flew away from the Moon. A few seconds after that, the Moon moved to cover all of Jupiter. A few minutes after that, Jupiter reappeared on the other side of the Moon, and even a few minutes after that the Moon moved completely away from Jupiter. Although hard to catch, planes cross in front of the Moon quite frequently, but the Moon won't eclipse Jupiter again for another three years. February 24, 2013 -After dinnertime at this time of year, four carnivore constellations stand in a row from the northeast to south. They're all seen in profile with their noses pointed up and their feet (if any) to the right: Ursa Major in the northeast (with the Big Dipper as its brightest part), Leo in the east (with the Moon by his forefoot tonight), Hydra the Sea Serpent in the southeast, and Canis Major in the south. -Telescope users in eastern North America can watch Jupiter's moon Europa reappear out of eclipse from Jupiter's shadow around 6:59 p.m. EST. Then Io reappears out of eclipse around 8:55 p.m. EST. Both events happen just east of the planet.  February 23, 2013 -At this time of year, the Big Dipper stands on its handle in the northeast during evening. The top of the Dipper — the two Pointer stars, pointing left to Polaris — are now at exactly Polaris's height around 8 p.m. (depending on where you live in your time zone). -Mercury is low in the western twilight and rapidly fading: from magnitude +0.8 on February 22nd to +4 on March 1st! Catch it early in the week before it's gone. -Mars is lost in the glow of sunset, even lower than Mercury. February 22, 2013 -This evening the Moon is left of Procyon and below Castor and Pollux. -Mercury (about magnitude –0.5) continues its excellent apparition in the evening twilight. Look for it low in the west-southwest as the sky darkens. No other point in the area is nearly so bright. -Mars (magnitude +1.2) is disappearing into the sunset, moving ever farther to Mercury's lower right -Comet Lemmon is passing through the Southern Hemisphere constellation of Tucana, just beside the Small Magellanic Cloud. Comet Lemmon is currently roughly Magnitude +5 and is expected to peak at Magnitude +3.0 come the beginning of April. The path is shown below.   February 21, 2013 -Early this evening, look lower right of the Moon for Procyon and upper left of the Moon for Castor and Pollux. Much farther to the lower right of Procyon shines bright Sirius. -Neptune is in conjunction with the Sun. February 20, 2013 -Have you ever seen Canopus, the second-brightest star after Sirius? Canopus lies almost due south of Sirius, by 36°. That's far enough south that it never appears above your horizon unless you're below latitude 37° N (southern Virginia, southern Missouri, central California). And there, you'll need a flat south horizon. Canopus transits the sky's north-south meridian just 21 minutes before Sirius does. -When to look? Canopus is at its highest point when Beta Canis Majoris's Mirzim, the star three finger widths to the right of Sirius is at its highest point crossing the meridian. Look straight down from Mirzim then. February 19, 2013 -The Moon after dark stands straight over Orion, who's standing straight upright in the south. -Saturn (magnitude +0.5, in Libra) rises in the east-southeast around 11 or midnight, well to the lower left of Spica. By the beginning of dawn Saturn is highest in the south — more or less between Spica, 18° to its right, and Antares farther to its lower left. Saturn is 4½° northwest of the wide double star Alpha Librae. In a telescope Saturn's rings are tilted 19.3° from edge-on, their most open of the year (by just a trace).  February 18, 2013 -The Moon now shines to the left or upper left of Jupiter and Aldebaran, drawing farther away from them through the evening. -Mars (magnitude +1.2) is disappearing into the sunset, moving ever farther to Mercury's lower right. -Mercury (about magnitude –0.5) continues its excellent apparition in the evening twilight. Look for it low in the west-southwest as the sky darkens. No other point in the area is nearly so bright. February 17, 2013 -The first-quarter Moon shines to the right of Jupiter just after dark, as shown below. Watch it move closer to Jupiter through the evening, by about one Moon-diameter per hour, as they tilt down toward the west. They set around 1 or 2 a.m. February 16, 2013 -Bright Jupiter shines upper left of the Moon. Aldebaran is to Jupiter's left, and the Pleiades are a little farther to Jupiter's right. -Mercury is at greatest elongation, 18° east of the Sun in evening twilight. A telescope shows (in reasonably good seeing) that this tiny little sphere, just 7 arcseconds wide, is now half-lit. February 15, 2013 -Comet PanSTARRS update: The incoming comet that we hoped would make a fine showing in March has been weakening. It may not even reach naked-eye visibility, what with its low altitude in the evening twilight. -Close flyby of asteroid 2012 DA14: This gymnasium-sized asteroid will miss Earth by just 18,000 miles (28,500 km) around 19:25 Universal Time today. It will then be as bright as 8th magnitude, moving across the stars by 0.8° per minute — and it will be in nighttime view from easternmost Europe (in late evening) across Asia to Australia (before dawn on the 16th local date). By the time it's visible in Western Europe it will be a little fainter, and by its visibility in North America it will be down to 11th to 13th magnitude, receding into the distance near the Little Dipper. Click here to find more information about tonight's asteroid fly by. -The Clay Center Observatory will be streaming the fly by at 6pm EST for those interested in watching.  -After dark, look right of the crescent Moon by roughly a fist-width at arm's length for the two or three leading stars of Aries, lined up almost vertically. -Algol should be at minimum light for a couple hours centered on 8:12 p.m. EST. February 14, 2013 -February is when Orion stands highest in the south in early evening. This season, Orion is framed by the two brightest points in the sky: Jupiter high to its upper right and Sirius down to its lower left. -Jupiter (magnitude –2.4, in Taurus) dominates the high south in early evening and the southwest later. To its left is orange Aldebaran; to its right are the Pleiades. This whole group sets around 2 a.m. In a telescope, Jupiter is shrinking as Earth pulls farther ahead of it in our faster orbit around the Sun. This week it shrinks from 42 to 41 arcseconds wide. February 13, 2013 -Look to the right of the Moon soon after dark for Gamma (γ) Pegasi, the leftmost star of the Great Square of Pegasus. The Great Square is standing on one corner. -Mars (magnitude +1.2) is becoming a real challenge as it sinks lower low into the sunset. Brighter Mercury is your marker for finding it. -Mars is currently on the far side of the Sun from us, but Mercury is swinging around to the Sun's near side as shown by its growing size and diminishing phase.  February 12, 2013 -Mercury shines far below the crescent Moon as twilight fades. The eclipsing binary star Algol should be at minimum light, magnitude 3.4 instead of its usual 2.3, for a couple hours centered on 11:23 p.m. EST. -Algol takes several additional hours to fade and to rebrighten. February 11, 2013 -Mercury shines lower left of the Moon, as shown below. And bring binoculars for a last shot at faint, low Mars. Mars (magnitude +1.2) is becoming a real challenge as it sinks lower low into the sunset. Brighter Mercury is your marker for finding it. February 10, 2013 -New Moon; exact at 2:20 a.m. EST on this date (11:20 p.m. on the 19th PST). Challenge: Catch your record young Moon? Very low in the west shortly after sunset, if the air is very clear, binoculars may show an extremely thin crescent Moon well to the lower right of Mercury and Mars (viewed from North America), as illustrated below. If you see the crescent from the Eastern time zone, you're seeing it when it's only 15 or 16 hours old — a remarkable record that you may not beat in a lifetime! Seen three hours later in twilight from the Pacific time zone, the Moon will be 18 or 19 hours old — still likely a record for your logbook. Record the time you detect the Moon to the minute, and calculate how long this is from the time of new Moon given above.  February 9, 2013 -Mars now appears 1.1° below brighter Mercury (for North America), low in the sunset glow. -Venus (magnitude –3.9) is buried deep in the glow of sunrise. February 8, 2013 -Mercury-Mars Conjunction. Mars is less than ½° from Mercury low in the west-southwest in bright twilight, as shown at right (for North America). They'll certainly be an interesting pair through a telescope, though both will be tiny and blurred at such a low altitude.  February 7, 2013 -Challenging Mercury-Mars conjunction. Look low in the west-southwest a half hour after sunset. Faint Mars is within 3/4° upper left of brighter Mercury (seen from North America), as shown here. Quite an interesting pair in binoculars!  February 6, 2013 -Jupiter (magnitude –2.5, in Taurus) dominates the high south in early evening, and the southwest later. To its left is orange Aldebaran; to its right are the Pleiades. The whole group sets around 2 or 3 a.m. -In a telescope, Jupiter is shrinking (from 43 to 42 arcseconds wide this week) as Earth pulls farther ahead of it in our faster orbit around the Sun.  February 5, 2013 -With the Moon gone from the evening sky, this week is a fine time to look for the zodiacal light from the Northern Hemisphere. At a clear, dark site with clean air, look west at the very end of twilight for a vague but huge, tall pyramid of pearly light. It's tilted left to align along the constellations of the zodiac — or more exactly, along the ecliptic line. So it points toward toward Jupiter. What you're seeing is sunlit interplanetary dust — comet and asteroid debris — orbiting the Sun near the plane of the solar system. -Comet PanSTARRS update. The incoming comet that we hoped would make a fine showing in March has been weakening. It may not even reach naked-eye visibility, what with its low altitude in evening twilight. The comet is currently expected to peak at magnitude +1 or +2 in March, not 0 or brighter as formerly predicted.  February 4, 2013 -Jupiter's biggest moon, Ganymede, fades into eclipse by Jupiter's shadow around 7:35 p.m. EST. It reappears around 9:53 p.m. EST. Both events take place just east of the planet. Europa happens to be just south of Ganymede's reappearance point, by a bit less than a Jupiter diameter. When can you detect the first trace of Ganymede coming back? Later, Jupiter's Great Red Spot rotates across the planet's centerline at 11:25 p.m. EST. -Mars (magnitude +1.2) is sinking deeper into the sunset. Brighter Mercury becomes your marker for finding it this week. February 3, 2013 -February is when Orion stands highest in the south in early evening. And this season, Orion is framed between the two brightest points in the sky: Jupiter high to its upper right and Sirius down to its lower left. Introduce them to someone! Mercury (magnitude –1.1) is emerging from the glow of sunset. On February 1st it's still very deep in bright twilight, but day by day it becomes higher and easier to see. Check for it each clear evening starting about 30 minutes after sunset, just above the west-southwest horizon. Bring binoculars. -There too is fainter Mars (magnitude +1.2). Mars is above Mercury until February 7th and 8th, when they pass less than 1° apart. After that Mercury is higher — coming into an excellent apparition of its own.  Mercury peaks in the early evening sky from February 11th to 21st, while much fainter Mars appears lower each evening. The two planets pass spectacularly close to each other on February 7th and 8th. Their disks are shown in their correct shapes and orientations, but their sizes are exaggerated hugely, roughly matching their appearance through a telescope at high magnification. February 2, 2013 -our latitude makes a big difference in how the constellations appear. (Your longitude does not.) For instance, if you're as far north as 46° (roughly Portland, Minneapolis, Montreal, and central France), bright Capella passes straight through your zenith around 8 or 9 p.m. If you're as far south as 21° N (Guadalajara, Cuba, the mid-Sahara, and Kolkata), Jupiter currently crosses straight overhead in the evening. -Wherever you are, Jupiter and Capella pass closest to your zenith exactly one hour apart. Jupiter goes first. -Saturn and the last-quarter Moon rise together tonight around midnight or 1 a.m. By dawn (Sunday the 3rd) they're high in the south, as shown above. February 1, 2013 -The sky's biggest well-known asterism (informal star pattern) is the Winter Hexagon or Winter Circle. It fills the sky toward the east and south these evenings. Start with brilliant Sirius at its bottom. Going clockwise from there, march through Procyon, then Pollux and Castor, then Menkalinen and Capella overhead, down to Aldebaran (overshone by Jupiter this season!), down to Rigel, and back to Sirius. January 31, 2013 -Jupiter's moon Io crosses Jupiter's face from 7:59 to 11:09 p.m. EST. Io's tiny black shadow follows behind across Jupiter from 10:10 p.m. to 12:21 a.m. EST. Meanwhile, Jupiter's Great Red Spot (actually pale orange-tan) crosses the planet's central meridian around 8:07 p.m. EST. Mercury is hidden deep in the sunset. -Saturn rises in the middle of the night this week and shines high during dawn. The Moon is positioned here for the middle of North America. The blue 10° scale is about the width of your fist at arm's length. January 30, 2013 -Saturn is at western quadrature: 90° west of the Sun in the morning sky. Mercury is hidden deep in the sunset. January 29, 2013 -Around 9 or 10 p.m. this week (depending on how far east or west you live in your time zone), brilliant Sirius is at its highest due south. -Mars (magnitude +1.2) still glimmers very low in the west-southwest in the fading glow of sunset. Don't confuse it with Fomalhaut well to its left.  January 28, 2013 -Once the waning gibbous Moon is well up in the east in mid- to late evening, look upper left of it for Regulus with the Sickle of Leo extending beyond, as shown here. Look about twice as far to the Moon's right for Alphard, the fire-colored heart of Hydra. -Jupiter (magnitude –2.5, in Taurus) is the first "star" to come out high in the southeast after sundown. It dominates the high south after dinnertime, with orange Aldebaran lower left or left of it, and the Pleiades to its upper right or right. -For many weeks, Jupiter has been drawing closer to forming a straight line with Aldebaran and Pleiades. It'll never get there. Jupiter reaches its stationary point on January 30th, when it ceases its retrograde (westward) motion against the stars and starts moving back eastward. -In a telescope, Jupiter has been slowly shrinking as Earth pulls ahead of it in our faster orbit around the Sun. It appears about 44 arcseconds wide. The 5th-magnitude star 0.1° south of it this week is Omega-2 Tauri. January 27, 2013 -The Moon shines high in the east by 9 p.m. Lower left of it, by roughly a fist-width at arm's length, sparkles Regulus in Leo, as shown below. The Sickle of Leo extends upper left from Regulus. The emergence of Leo in the evening sky is always an early sign that spring is eventually coming. -Venus (magnitude –3.9) is just above the southeast horizon 20 minutes before your local sunrise. It's getting lower each morning. Bring binoculars. January 26, 2013 -Full Moon (exact at 11:38 p.m. EST). The Moon is in dim Cancer, with Procyon shining off to its right or upper right during evening, and Pollux and Castor above it. -Algol in Perseus is at its minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 6:26 p.m. EST. Watch it gradually rebrighten though the evening. January 25, 2013 -This evening the Moon shines not quite midway between Procyon to its lower right and Pollux to its upper left. -Around 10 p.m. this week (depending on how far east or west you live in your time zone), brilliant Sirius is at its highest due south. -Sirius is the brightest star in the night sky — and are you far enough south to see the second brightest, Canopus? In one of the many interesting coincidences that devoted skywatchers know about, Canopus lies almost due south of Sirius: by 36°. That's far enough south that it never appears above your horizon unless you're below latitude 37° N (southern Virginia, southern Missouri, central California). And there, you'll need a flat south horizon. Canopus transits the sky's north-south meridian just 21 minutes before Sirius does. -When to look? Canopus is at its highest point when Beta Canis Majoris — Mirzim, the star a few finger-widths to the right of Sirius — is at its highest point crossing the meridian. Look straight down from Mirzim then. January 24, 2013 -The bright Moon shines about midway between Betelgeuse in Orion's shoulder to its right, and Pollux in Gemini to the Moon's left. The star above Pollux is Castor. Below the Moon is Procyon in Canis Minor. -Mars (magnitude +1.2) still glimmers very low in the west-southwest in the fading glow of sunset. Don't confuse it with Fomalhaut far to its left. (On January 24th Mars is at perihelion, its closest to the Sun in its orbit.) -Venus (magnitude –3.9) is just above the southeast horizon about 30 minutes before your local sunrise. It's lower each morning. How much longer can you keep it in view? January 23, 2013 -Week by week, watch the Big Dipper rearing higher up in the northeast as we leave more of winter behind us. -Two of Jupiter's moons emerge out of eclipse by Jupiter's shadow tonight: Europa at 7:05 p.m. EST, and Io at 12:16 a.m. EST. With a telescope, watch both swell into view off Jupiter's eastern limb. Meanwhile, Jupiter's Great Red Spot rotates across the planet's centerline around 11:27 p.m. EST. -Algol is at its minimum brightness for a couple hours centered on 9:37 p.m. EST.  January 22, 2013 -By now the Moon has moved eastward from Jupiter along its orbit to shine well to Jupiter's left after dinnertime, as shown above. -Look below the Moon for Orion, and far below Orion for brilliant Sirius. January 21, 2013 -Close conjunction of the Moon and Jupiter. Look for a bright "star" unusually near the waxing gibbous Moon this evening, as shown above. The Moon passes less than 1° from it for most of the U.S. and Canada. This is an opportunity where you can try to find Jupiter before the sun sets. It is the faint dot beside the moon at sunset! Think photo opportunity; use a long lens, or zoom to the max. In much of South America the Moon actually occults (covers) Jupiter; To find out where you can see the occultation, go here: http://www.lunar-occultations.com/io...122jupiter.htm -Although they look close together, the Moon is only 1.3 light-seconds distant from Earth, while Jupiter is 1,700 times farther away at a distance of 37 light-minutes. January 20, 2013 -The naked-eye eclipsing variable star Algol is at its minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours tonight centered on 12:48 a.m. EST (9:48 p.m. PST.) It takes several additional hours to fade and to rebrighten. -The waxing gibbous Moon highlights an interesting section of the winter sky. (The Moon symbols are positioned for the middle of North America. They are drawn three times the Moon's actual apparent size.) January 19, 2013 -In twilight, bright Jupiter comes into view well to the lower left of the Moon. By 8 p.m. things have turned around and Jupiter is shining to the Moon's left or upper left. Closer to the Moon's lower left is the big, dim head of Cetus with its one 2nd-magnitude star, orange Alpha Ceti (Menkar). -Venus (magnitude –3.9) is just above the southeast horizon about 30 minutes before your local sunrise. It's lower each morning. How much longer can you keep it in view? January 18, 2013 -First-quarter Moon. The Moon is exactly half lit at 6:45 p.m. EST. In early evening, look above the Moon by about about a fist-width at arm's length for the brightest two or three stars of Aries. These are aligned more or less vertically. January 17, 2013 -Bright Capella high overhead and bright Rigel in Orion's foot, both magnitude 0, have almost the same right ascension — so they transit your north-south meridian at the almost same time. Capella passes closest to the zenith around 9 or 10 p.m. this week, depending on how far east or west you live in your time zone. (It goes exactly through the zenith if you're at latitude 46° north: Portland, Oregon; Montreal; central France.) So, whenever Capella is closest to the zenith, Rigel always marks true south over your landscape. January 16, 2013 -Venus (magnitude –3.9) is getting lower in the dawn each morning. Look for it above the southeast horizon about 30 minutes before your local sunrise. -Mars (magnitude +1.2, in Sagittarius) still glimmers very low in the west-southwest in the fading glow of sunset. Don't confuse it with Fomalhaut far to its left. January 15, 2013 -Mercury is hidden in conjunction with the Sun. -Saturn (magnitude +0.6, in Libra) rises in the east-southeast around 1 or 2 a.m. local time. By the beginning of dawn it's fairly high in the southeast. That's the best time to get your telescope on it. Saturn's rings are tilted 19° to our line of sight, the widest open they've been for seven years.   January 14, 2013 -Before moonlight returns in force to wash out low-surface-brightness telescopic objects, try tonight for the Bubble and Pac-Man Nebulae in Cassiopeia. -Jupiter (magnitude –2.7, in Taurus) is the first "star" to appear in the eastern sky after sundown. It dominates the high southeast after dusk, with orange Aldebaran below it and the Pleiades over it as shown below. They tilt around and pass highest in the south around 8 or 9 p.m. local time. In a telescope Jupiter is still about 45 arcseconds wide. January 13, 2013 -In twilight this evening, look below the waxing crescent Moon in the west to see if you can still spot faint little Mars, as shown here. Mars has been hanging in there in twilight ever since August! but is now gradually creeping lower week by week. January 12, 2013 -As twilight turns to night, look low in the northwest for Vega. To its upper left, by two or three fists at arm's length, shines Deneb. Deneb is the head of the big Northern Cross, which is now swinging down and soon will stand nearly upright on the northwest horizon (as seen from mid-northern latitudes). -The crescent Moon marches higher each evening as it waxes thicker farther away from the Sun. Use the Moon to locate faint little Mars. January 11, 2013 -In early evening at this time of year, the Great Square of Pegasus balances on one corner high in the west. The vast Andromeda-Pegasus constellation complex runs all the way from near the zenith (Andromeda's foot) down through the Great Square (Pegasus's body) to low in the west (Pegasus's nose). -New Moon (exact at 2:44 p.m. EST). January 10, 2013 -Saturn (magnitude +0.6, in Libra) rises in the east-southeast around 2 a.m. local time. By the beginning of dawn it's fairly high in the southeast. That's the best time to get your telescope on it. Saturn's rings are tilted 19° to our line of sight, the widest open they've been in seven years. January 9, 2013 -The waning crescent Moon appears lower each morning until dawn on Thursday, when it forms a spectacular pair with Venus very low in the southeast. -Venus (magnitude –3.9) appears lower in the dawn each morning. Look for it above the southeast horizon about 45 minutes before your local sunrise.  January 8, 2013 -Jupiter's moon Io crosses Jupiter's face from 8:03 to 10:13 p.m. EST, followed by Io's tiny black shadow from 8:55 to 11:06 p.m. EST. Jupiter's Great Red Spot transits the planet's central meridian around 2:02 a.m. Wednesday morning EST. -Mars (magnitude +1.2, in Sagittarius) still glimmers low in the southwest in the fading glow of sunset. Don't confuse it with Fomalhaut far to its left. January 7, 2013 -As dawn begins to brighten on Tuesday morning, spot the waning crescent Moon in the southeast. Below it is Antares, a summer-evening star just beginning its months-long trek backward through the night. Much farther lower left of the Moon, Venus rises. Higher in the south are Saturn and, two fists to Saturn's right, Spica. The waning crescent Moon appears lower each morning until dawn on Thursday, when it forms a spectacular pair with Venus very low in the southeast. January 6, 2013 -At this coldest time of the year, Sirius rises around 7 p.m. (depending on how far east or west you live in your time zone). Orion's three-star Belt points down almost to Sirius's rising place; watch for it there. Once Sirius is up, it twinkles slowly and deeply through the thick layers of low atmosphere, then faster and more shallowly as it gains altitude. Its flashes of color also speed up and blend into shimmering white as the star climbs to shine through thinner air. -Watch Jupiter gradually creeping toward a better lineup between Aldebaran and the Pleiades. It won't quite get there, however. Instead it will gradually stop and reverse direction at the end of January, just short of forming a straight line. (The 10° scale is about the width of your fist held at arm's length.)  January 5, 2013 -Before dawn Sunday morning, Spica shines to the upper right of the waning Moon, and Saturn shines to the Moon's upper left, as shown here. -Mercury is hidden in the glare of the Sun. -Venus (magnitude –3.9) appears lower in the dawn each morning. Look for it above the southeast horizon about 45 minutes before your local sunrise.  January 4, 2013 -The latest sunrise of the year happens this morning (at 40° north latitude). -Last-quarter Moon tonight (exact at 10:58 p.m. EST). The Moon, between Corvus and the head of Virgo, rises around 11 or midnight. By dawn Saturday morning, the Moon is high in the south with Spica and Saturn to its left, as shown here. January 3, 2013 -In this coldest time of the year, the dim Little Dipper hangs straight down from Polaris after dinnertime as if from a nail on the cold north wall of the sky. -Algol should be at minimum light for a couple hours centered on 7:52 p.m. EST. January 2, 2012 -By about 8 or 9 p.m., the Big Dipper is swinging upward in the north-northeast. It drags the end of its handle along the horizon, depending on your latitude, as its bowl rises upward. -Earth is at perihelion, its closest to the Sun for the year (just 3% closer than at aphelion in July). -Saturn (magnitude +0.7, in Libra) rises in the east-southeast around 2 or 3 a.m. local time. By the beginning of dawn it's fairly high in the southeast. That's the best time to get your telescope on it. Saturn's rings are tilted 19° to our line of sight, the widest open they've been in seven years. January 1, 2012 -The two leading asteroids, Ceres and Vesta, are still in good binocular range at magnitudes 7.1 and 6.9, respectively. Vesta is near Jupiter and Aldebaran, and Ceres is between the horns of Taurus not far away. A finder chart exists here: http://media.skyandtelescope.com/doc...CeresVesta.pdf  December 31, 2012 -After the New Year's cheering at midnight is over, step outside into the cold, silent dark. The bright Moon will be shining in the southeast, with Regulus to its left. Due south is Sirius at its greatest height, with Orion to its upper right and the Jupiter-Aldebaran-Pleiades arrangement farther on — tipped differently than we're used to seeing it in the evening. Upper left of Sirius is Procyon. -Algol should be at its minimum light, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 11:02 p.m. EST. Algol takes several additional hours to fade and to rebrighten. December 30, 2012 -Sirius and Procyon in the balance: Sirius, the Dog Star, sparkles low in the east-southeast after dinnertime. Procyon, the Little Dog Star, shines in the east about two fist-widths at arm's length to Sirius's left. If you live around latitude 30° north (Tijuana, New Orleans, Jacksonville), the two canine stars will be at the same height above your horizon soon after they rise. If you're north of that latitude, Procyon will be higher. If you're south of there, Sirius will be the higher one. -Jupiter forms a straight line with Aldebaran and, between them, 3.5-magnitude Epsilon Tauri, the other tip of the Hyades V pattern. December 29, 2012 -In early evening at this time of year, the Great Square of Pegasus balances on one corner high in the west. The vast Andromeda-Pegasus constellation complex runs all the way from near the zenith (Andromeda's foot) down through the Great Square (Pegasus's body) almost to the western horizon (Pegasus's nose). -Mars (magnitude +1.2, in Sagittarius) still remains low in the southwest in evening twilight. Don't confuse it with Fomalhaut far to its left or upper left. In a telescope Mars is just a tiny blob 4.3 arcseconds in diameter. December 28, 2012 -Look left of the just-past-full Moon this evening for Castor and Pollux, one above the other. Castor is the one on top. Farther right of the Moon is Orion. -Mercury (magnitude –0.6) is disappearing low in bright dawn, well to the lower left of Venus low in the southeast. They're 11° to 13° apart. Look early in the week, and bring binoculars. -Venus (magnitude –3.9) is still the bright "Morning Star," but it's moving lower in the dawn every week. Look southeast. December 27, 2012 -Full Moon tonight (exact at 5:21 a.m. Friday morning Eastern Standard Time). The Moon is in the top of Orion's dim club, just under the feet of the Castor figure in Gemini. -Mercury (magnitude –0.5) can be spotted during dawn, well to the lower left of brilliant Venus low in the southeast. They're 8° or 9° apart. -For a neat way to see how fast planets move in just one week relative to stars, I've included both today's picture of Mercury and Venus's location with last week as well.   December 26, 2012 -Now the Moon is lower left of Jupiter in the evening, as shown above. The Moon is in the area of Beta and especially Zeta Tauri, the horn tips of Taurus. -Jupiter (magnitude –2.8, in Taurus) is up and glaring in the east as twilight fades. It climbs to dominate the high eastern and southeastern sky in the evening, with orange Aldebaran 5° below it and the Pleiades twice as far to its upper right. Jupiter is highest in the south around 10 p.m. local time. In a telescope it's still a big 47 arcseconds wide.  December 25, 2012 -Christmas conjunction of the Moon and Jupiter, with Aldebaran right nearby! Jupiter and the Moon are only a degree or two apart, depending on your location (in the Americas) and the time of evening. Watch them change separation and orientation as the night progresses. Binoculars show stars of the big, loose Hyades cluster in their background. December 24, 2012 -The Moon, nearly full, shines upper right of Jupiter and Aldebaran early this evening, as shown above. Look too for the Pleiades closer left of the Moon. By around 9 p.m. Jupiter and the Moon are level with each other, when they're both very high overhead. December 23, 2012 -With the coming of winter, the Great Square of Pegasus is once again balancing on one of its corners as it descends the western evening sky. -It's a busy evening at Jupiter. Ganymede, Jupiter's largest satellite, emerges from behind Jupiter's eastern limb at 7:26 p.m. EST — then just 6 minutes later it disappears into eclipse by the planet's shadow. Ganymede emerges from Jupiter's shadow farther out from the planet at 9:42 p.m. EST. Twenty-two minutes after that, Io starts crossing the planet's face, followed by Io's tiny black shadow at 10:36 p.m. EST. At 10:45 p.m. EST, Jupiter's Great Red Spot should cross the planet's central meridian. December 22, 2012 -Every year during Christmas season, Sirius rises in the east-southeast, far below Orion, around 7 or 8 p.m. When Sirius is still low, binoculars often show it twinkling in vivid colors. All stars do this when low. But Sirius is the brightest, making the effect more pronounced. -Venus (magnitude –3.9) is still the bright "Morning Star," but it's moving lower in the dawn every week. Look southeast. December 21, 2012 -By about 9 p.m. at this time of year (depending on how far east or west you live in your time zone), the dim Little Dipper hangs straight down from Polaris, as if from a nail on the cold north wall of the sky. If you have a light-polluted sky, all you may see are Polaris and the two stars forming the far end of the Little Dipper's bowl: Kochab and Pherkad, the "Guardians of the Pole." -Winter begins in Earth's Northern Hemisphere at the solstice, 6:12 a.m. EST, when the Sun begins its six-month return northward. This is the shortest day of the year and the longest night. (But the Earth didn't flip over? No continents flying loose? Maybe next year.) December 20, 2012 -Jupiter's moon Europa crosses Jupiter's face tonight from 9:45 p.m. to 12:07 a.m. EST, followed by its tiny black shadow (plainer to see in a telescope) from 10:40 p.m. to 1:04 a.m. EST. -Look for Antares and Mercury low in the Southeast just before sunrise tomorrow morning. Antares is in the constellation Scorpius - the constellation that 'drags' the bulge of the milky way behind it. December 19, 2012 -The first-quarter Moon shines at the dim Circlet of Pisces, below the much larger and brighter Great Square of Pegasus early in the evening. -By week's end, use binoculars to try to spot Antares twinkling low in the dawn below Venus and to the right of Mercury. December 18, 2012 -After dinnertime this week, Cassiopeia stands at its very highest in the north like a flattened M (for skywatchers at mid-northern latitudes). The Milky Way runs through it, stretching all the way down to the east horizon on one side and the west horizon on the other. Given the quality of your sky, how much of the Milky Way (if any) can you trace out? December 17, 2012 -The first-discovered asteroid, 1 Ceres, is at opposition tonight. It's not far from 4 Vesta, which is also in Taurus along with Jupiter. Ceres and Vesta are now magnitudes 6.7 and 6.5, respectively. -Mars (magnitude +1.2, in Sagittarius) still remains low in the southwest in evening twilight. In a telescope it's just a tiny blob 4.3 arcseconds in diameter — hardly larger than Uranus! December 16, 2012 -Jupiter's moon Io crosses Jupiter's face from 8:19 to 10:29 p.m. EST, closely followed by its tiny black shadow (much plainer to see in a telescope) from 8:41 to 10:52 p.m. EST. Meanwhile, the Great Red Spot should cross Jupiter's central meridian around 10:00 p.m. EST. -Jupiter (magnitude –2.8, in Taurus) is already glaring in the east as twilight fades. It climbs to dominate the eastern and high southeastern sky into the evening, with orange Aldebaran 5° below it and the Pleiades about twice as far to its upper right. Jupiter is highest in the south around 10 or 11 p.m. In a telescope it's still a big 48 arcseconds wide, essentially as large as it ever appears. December 15, 2012 -In early evening, the "Summer Star" Vega is still the brightest thing in the northwestern sky, though it's moving ever lower. The brightest above it is Deneb. Vega is 25 light-years away; supergiant Deneb is about 1,400. -Mercury, Venus, and Saturn form a long diagonal line in the southeast as dawn begins to brighten. Venus is by far the brightest, at magnitude –3.9. Look far to its upper right for Saturn, magnitude +0.7, and farther on for Spica, magnitude +1.0. Look lower left of Venus for Mercury, magnitude –0.5, now moving a little lower each day. The whole line of four points is now about 45° long. December 14, 2012 -Orion stands centered between two bright lights this year. High above it during evening shines bright Jupiter (with its orange sidekick Aldebaran). A similar distance below Jupiter, Sirius rises around 8 p.m. (the time depends on your location) — with its white sidekick Mirzam. -Sirius, just 8.6 light-years away, is the brightest star in the night sky. It's also the closest that's ever visible to the unaided eye from mid-northern latitudes. -Algol should be at minimum light for a couple hours centered on 6:07 p.m. EST. Watch it rebrighten for much of the rest of the night. -Jupiter's Great Red Spot should cross Jupiter's central meridian around 8:22 p.m. EST. December 13, 2012 [b]-The Geminid meteor shower, often the best in the annual meteor calendar, should be at its maximum late tonight. And there's no Moon. Expect a count of 120 meteors / hour! -On the same dates, a new shower may also be making its appearance. Debris streams from Comet Wirtanen, crossing our orbit for the first time, could produce a couple dozen meteors visible per hour from December 10th to 14th from a radiant just south of the Great Square of Pegasus, according to computer models by Russian meteor scientist Mikhail Maslov. The "Piscids" would be unusually slow moving. -The new shower doesn't have a name yet. Before naming it, astronomers will wait to see if it is real. If any meteors do materialize, they might be called "Piscids." The shower's radiant is located in the constellation Pisces, according to Maslov's dynamical models of the debris stream. Maslov also predicts that the meteors will be very slow moving, which should help novice sky watchers distinguish them from the faster Geminids. More Information here about this new meteor shower. -New Moon (exact at 3:42 a.m. on the 13th EST).  December 12, 2012 [b]-As the stars come out in late twilight, the flattened W of Cassiopeia is still standing on one end high in the northeast. By as early as 8 p.m. it turns around to be a horizontal M, even higher in the north. -Mercury, Venus, and Saturn form a diagonal line in the southeast as dawn begins to brighten. Venus is by far the brightest, at magnitude –3.9. Look well to its upper right for Saturn, magnitude +0.7, and farther on for Spica, magnitude +1.0. Look lower left of Venus for Mercury, magnitude –0.5. Mercury is having its best morning apparition of 2012. This line of four points is lengthening: it grows from 33° to 42° long this week. December 11, 2012 -Flyby of Toutatis. The small Earth-crossing asteroid 4179 Toutatis is performing one of its close approaches to Earth tonight, as it does every four years. Locate it creeping across the stars of Cetus and Pisces using at least a 3- or 4-inch telescope tonight through Friday night. It's magnitude 10.9 tonight and peaks at 10.5 on Friday. Use the finder charts for each of these four nights here: http://www.skyandtelescope.com/obser...-Flies-By.html Algol should be at its minimum light for a couple hours centered on 9:18 p.m. EST. Here's a comparison-star chart giving the magnitudes of three stars near Algol; use them to judge its changing brightness. December 10, 2012 -Low in the southeast in early dawn Tuesday morning, the waning crescent Moon is beautifully paired with Venus, as shown at right.  December 9, 2012 -Jupiter's Great Red Spot should transit the planet's central meridian around 9:15 p.m. EST. -At dawn Monday morning, look upper left of the Moon for Saturn, and lower left of the Moon for little Alpha Librae partway down to Venus and Mercury, as shown at right. If you catch Alpha Lib before dawn becomes too bright, binoculars will show it to be a wide double star. December 8, 2012 -Since Jupiter is just past opposition, the asteroids Ceres and Vesta in Jupiter's vicinity are near their oppositions too. Vesta's opposition is tonight. It's magnitude 6.4, and Ceres is 6.9. Spot them in binoculars this month using the page under the Upcoming Events Tab. They're near the horns of Taurus. -Algol in Perseus, the prototype eclipsing binary star, should be in one of its periodic dimmings, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 12:29 a.m. Sunday morning EST; 9:29 p.m. Saturday evening PST. Algol takes several additional hours to fade and to rebrighten. -Jupiter's moon Io reappears out of eclipse from Jupiter's shadow at 11:49 p.m. EST; 8:49 p.m. PST. -For all of Jupiter's satellite events, as well as all of the Great Red Spot's transit times, Sky & Telescope has released this Jupiter'sMoons app. https://itunes.apple.com/us/app/jupi...577009038?mt=8 -During dawn Sunday morning the waning crescent Moon hangs close to Spica, as shown at right. -At dawn, watch the waning crescent Moon step down past Spica, Saturn, Venus and Mercury from one morning to the next. As always, this scene is drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. For clarity, the Moon is shown three times actual size. December 7, 2012 -This is the time of year when the Andromeda Galaxy, M31, passes the zenith in early evening for skywatchers at mid-northern latitudes. It goes exactly through your zenith if you're at 41° north latitude (New York, Denver). When this happens depends on your location. December 6, 2012 -Last-quarter Moon (exact at 10:31 a.m). The Moon rises around the middle of the night tonight. In the small hours of Friday morning it climbs the eastern sky beneath Leo. -Jupiter's Great Red Spot crosses Jupiter's central meridian around 11:45 p.m. EST. December 5, 2012 -Ganymede, the largest satellite of Jupiter, crosses Jupiter's face tonight from 9:25 to 11:17 p.m. EST, closely followed by its black shadow from 9:37 to 11:44 p.m. EST. In amateur telescopes, Ganymede's shadow will be much more obvious against Jupiter's bright surface than Ganymede itself is. -Under the "Upcoming Events" tab, you can now observe the positions of both Ceres and Vesta until March. December 4, 2012 -Sometime between 6 and 8 each evening now (depending on how far east or west you live in your time zone), bright Vega sinking in the northwest, and equally bright Capella climbing in the northeast, will be at exactly the same height. How accurately can you time their balance moment for your location? -Mars (magnitude +1.2, in Sagittarius) remains low in the southwest in evening twilight. In a telescope it's just a tiny blob 4.4 arcseconds in diameter. December 3, 2012 -By 8 or 9 p.m., wintry Orion is well up in the east-southeast. Orion's Belt in his middle points up more or less toward Aldebaran and bright Jupiter. And it points down toward where Sirius, the brightest star of the night, is about to rise. Watch for it. -Jupiter (magnitude –2.8, in Taurus) was at opposition yesterday (opposite the Sun as seen from Earth). It rises around sunset, climbs the eastern sky in the evening, shines highest in the south around midnight, and sets in the west around sunrise. Orange Aldebaran is 5° to its lower right during evening. Above them are the Pleiades. In a telescope, Jupiter is big 48 arcseconds wide, essentially as large as ever appears. December 2, 2012 -Jupiter is at opposition tonight: opposite the Sun as seen from Earth. So it rises around sunset, shines highest in the south around midnight, and sets around sunrise. Whenever Jupiter comes to opposition at this time of year, it's shining near Aldebaran and the Pleiades. -Mercury, Venus, and Saturn form a diagonal line in the southeast when dawn behind to brighten. Venus is by far the brightest at magnitude –3.9. Look upper right of it for distant Saturn, magnitude +0.7. Look lower left of Venus for Mercury, magnitude –0.5. Mercury is having an excellent apparition through the first half of December. This diagonal line of three lengthens from 13° to 19° long this week. Added bonus: Look upper right of the planet lineup for Spica, similar to Saturn at magnitude +1.0. December 1, 2012 -Since Jupiter just about at opposition, the asteroids Ceres and Vesta in Jupiter's vicinity are near opposition too. Vesta has brightened to magnitude 6.6, Ceres 7.2.Spot them here. They're near the horns of Taurus. This evening you'll have the darkest view of them shortly before moonrise. (The Moon rises around 7 p.m. depending on your location.) November 30, 2012 -The waning Moon rises less than an hour after the end of twilight. Once it's up, look to the right of it (by a bit more than a fist-width at arm's length) for orange-red Betelgeuse sparkling in Orion's rising shoulder.  November 29, 2012 -After the Moon rises this evening, spot Jupiter and fainter Aldebaran to its upper right, and Capella farther to its upper left. -Jupiter's Great Red Spot should cross Jupiter's central meridian around 11:00 p.m. EST (8:00 p.m. PST). November 28, 2012 -The Moon shines close to Jupiter and Aldebaran this evening, with the dimmer Pleiades above them. Think photo opportunity! Use a long (or zoomed) lens, and try a variety of exposures to catch the faint stars as well as the bright Moon. -Mars (magnitude +1.2, in Sagittarius) remains low in the southwest in evening twilight. In a telescope it's just a tiny blob 4.4 arcseconds in diameter.  November 27, 2012 -Full Moon tonight and tomorrow night. This evening, look lower left of the Moon for Jupiter and orange Aldebaran. Look upper left of the Moon for the fainter Pleiades cluster (binoculars help), and far left for Capella (out of the frame here). -A weak penumbral eclipse of the Moon occurs before and/or during dawn Wednesday morning for western North America. The penumbra is the pale outer fringe of Earth's shadow. The Moon will be deepest in it from 6:18 to 6:48 a.m. PST on Wednesday the 28th (14:18 to 14:48 on the 28th Universal Time). Look for a weak shading on the Moon's north (upper right) side. The farther in from the West Coast you are, the brighter the dawn and the lower the Moon will be. -The penumbral eclipse takes place high in the middle of the night for the longitudes of Australia and Japan, in late evening of the 28th local date for China and Southeast Asia, and early that evening for India with the Moon still low in the east. More details here:  November 26, 2012 -As dawn begins on Monday and Tuesday mornings, look southeast to spot bright Venus and fainter Saturn less than 1° apart. As dawn brightens further, look far to their lower left for Mercury.  November 25, 2012 -Venus, brilliant at magnitude –3.9, and Saturn, much fainter at magnitude +0.6, shine together in the southeast during dawn. Saturn begins the week 3° to Venus's lower left (on Saturday morning the 24th). It passes about 0.8° by Venus on the 26th and 27th, and by November 30th it's 4° to Venus's upper right. This is a rare opportunity to catch both Venus and Saturn within a moon's field of view of each other, meaning if you have a telescope or binoculars, you will be able to see both planets! -Mercury also joins the show enterring its best apparition of the year for mid-northern latitude viewers, meaning this is the highest Mercury will be visible this year. November 24, 2012 -Look left of the Moon this evening, by a fist-width at arm's length or a little more, for the two or three brightest stars of Aries. -Mercury emerges into dawn view around November 24th or so, brightening from magnitude +1 to 0 this week. Look for it just above the east-southeast horizon in early dawn, far to the lower left of Venus and Saturn as shown here. Mercury is beginning its best apparition of the year for viewers at mid-northern latitudes. November 23, 2012 -Some pre-telescopic astronomy: Sometime between 6:30 and 8:30 this evening, depending on how far east or west you live in your time zone, bright Vega sinking in the northwest and bright Capella climbing in the northeast (well left of brighter Jupiter) will be at exactly the same height. How accurately can you time this event for your location? An astrolabe would help. -Altair is the brightest star in the west-southwest. (It's far lower left of brighter Vega.) Look above Altair, and perhaps a bit left, for the dim but distinctive little constellation Delphinus, the Dolphin. November 22, 2012 -The Moon is under the Great Square of Pegasus as the stars come out. -Jupiter's moon Io disappears into eclipse by Jupiter's shadow, barely beyond the planet's western edge, at 11:20 p.m. EST (8:20 p.m. PST). Jupiter's Great Red Spot transits the planet's central meridian around 10:16 p.m. EST.  November 21, 2012 -Algol is at minimum light again, for a couple hours centered on 7:34 p.m. EST. Algol takes several additional hours to rebrighten. -Venus (magnitude –3.9, in Virgo) rises in the east an hour before the first glimmer of dawn. By dawn it's shining brightly in the east-southeast, as shown above. Look for much-fainter Saturn lower left of Venus, and Spica to Venus's right or upper right. November 20, 2012 -First-quarter Moon (exact at 9:31 a.m.). The Moon shines high in the south in early evening, below the Water Jar of Aquarius. -Saturn (magnitude +0.6, in Virgo) is lower left of bright Venus before and during dawn. They appear closer together every day. They're on their way to a conjunction less than 1° apart on the American mornings of November 26th and 27th. November 19, 2012 -Fomalhaut, the "Autumn Star," culminates (reaches its highest point due south) around 7 p.m. now, depending on how far east or west you live in your time zone. High above, the western side of the Great Square of Pegasus points almost down to it. The other side of the Great Square points down roughly to Beta Ceti (Diphda or Deneb Kaitos), not quite so far. November 18, 2012 -A low-altitude challenge: If the sky is very clear as twilight fades, aim your scope at tiny little Mars from a site with a low southwestern view. Follow Mars down as night falls. Can you detect the Lagoon Nebula, M8, and its embedded star cluster 1/3° or so to Mars's right? -Algol in Perseus, the prototype eclipsing binary star, should be in one of its periodic dimmings, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 10:45 p.m. EST. Algol takes several additional hours to fade and to rebrighten.  November 17, 2012 -With a small telescope, watch Jupiter's moon Ganymede slowly disappear into eclipse by Jupiter's shadow around 11:30 p.m. EST; 8:30 p.m. PST. Ganymede is just off Jupiter's western side. -At roughly the same time, Jupiter's Great Red Spot (actually pale orange-tan) appears nearest to the center of the planet's disk.  November 16, 2012 -Spot the crescent Moon in the west as twilight fades, and use it to guide your way down to little Mars, as shown here. -The Leonid meteor shower, normally weak but occasionally surprising, should be at its best in the hours before dawn Saturday morning. Under a dark sky you may see about a dozen to 20 Leonids per hour. There is no Moon. November 15, 2012 -The thin waxing crescent Moon shines to the right of distant little Mars in evening twilight, as shown here. November 14, 2012 -Vega is the brightest star in the west in early evening. The brightest far left of it, in the southwest, is Altair. Altair's 3rd-magnitude companion Gamma Aquilae (Tarazed), a finger's width at arm's length from it, is now to Altair's right. -Saturn (magnitude +0.6, in Virgo) is emerging into dawn view low in the east. Look for it below or lower left of bright Venus. They appear closer together every day. November 13, 2012 -Orion is up in the east by about 9 p.m. now, depending on where you live in your time zone. Orion's three-star Belt is nearly vertical. Orange Betelgeuse is to the Belt's left and white Rigel is to its right. Earlier in the evening, keep watch for Betelgeuse rising far below Jupiter. -A total eclipse of the Sun crosses parts of Australia and the South Pacific; you can see this eclipse if you live in the arc in the below image.  November 12, 2012 -Fomalhaut, the "Autumn Star," culminates (reaches its highest point due south) not long after dark now. The western side of the Great Square of Pegasus, high above, points almost down to it. The other side of the Great Square points down roughly to Beta Ceti (Diphda or Deneb Kaitos), not quite so far. November 11, 2012 -On Monday morning before sunrise, look below bright Venus in the east for the thin waning Moon with Saturn to its left, as shown here. Binoculars will help. Saturn is just beginning its year-long 2012–13 apparition.  November 10, 2012 -Jupiter's moon Ganymede reappears out of eclipse from the planet's shadow around 10:35 p.m. EST, only to disappear behind Jupiter's western limb 20 minutes later. A small telescope will show these proceedings. -Venus and the waning crescent Moon shine low in the east early Sunday morning, from pre-dawn to sunrise, as shown here. Can you follow them even past sunrise? Binoculars help — but be careful not to sweep up the Sun itself by accident! November 9, 2012 -The Moon has moved closer to Venus before and during dawn Saturday morning, as shown here. -Tonight, Jupiter's moon Europa disappears into eclipse by Jupiter's shadow around 1:11 a.m. Saturday morning EST (10:11 p.m. Friday evening PST). A small telescope will show it fading out of sight a little off the planet's western limb. November 8, 2012 -Early riser's sky sights: Before and during dawn Friday morning, the waning Moon shines high in the southeast. Venus blazes far to its lower left. Look upper left of Venus by a similar distance for Arcturus. Down below Venus is fainter Spica.. November 7, 2012 -The tiny black shadow of Io crosses Jupiter's face tonight from 10:11 p.m. to 12:21 a.m. EST, with Io itself following behind from 10:49 p.m. to 12:58 a.m. EST. -Uranus (magnitude 5.8, in Pisces) and Neptune (magnitude 7.9, in Aquarius) are in in good view in the south during evening. -If you have a large scope, have you ever tried for the moons of Neptune and Uranus? The brightest are about magnitude 13.5. Read more, and print charts for your time and date, at http://www.skyandtelescope.com/obser.../13795272.html and http://www.skyandtelescope.com/obser...s/3310476.html . November 6, 2012 -Last-quarter Moon tonight (exact at 7:36 p.m. EST). The half-lit Moon rises around 11 p.m. or midnight local time. Once it's well up, look left of it for the Sickle of Leo and right of it for the dimmer Head of Hydra. -Venus (magnitude –4.0, in Virgo) rises due east in darkness more than an hour before the first glimmer of dawn. By dawn it's shining brightly fairly high. November 5, 2012 -By 8 p.m. Vega is shining in the west-northwest. It's the brightest star there. Look well left of it for Altair in the west-southwest. Above Altair, by a little more than a fist-width at arm's length, is the dim but distinctive little constellation Delphinus, the Dolphin. -Saturn will emerge from the glow of the sunrise by the end of the week. November 4, 2012 -This is the time of year when the W of Cassiopeia stands on end (its fainter end) high in the northeast in early evening. This is also when the Big Dipper lies level low in the north-northwest. -Mars (magnitude +1.2, in Ophiuchus) remains low in the southwest in evening twilight. November 3, 2012 -Fomalhaut, the "Autumn Star," culminates (reaches its highest point due south) around 9 p.m. daylight saving time. The western side of the Great Square of Pegasus, high above, points almost down to it. The other side of the Great Square points down roughly to Beta Ceti (Diphda), not quite so far. -Standard time returns (for most of North America) at 2 a.m. tonight. Clocks "fall back" an hour.  November 2, 2012 -Once the waning gibbous Moon rises high late this evening, look lower right of it for wintry Orion making his sparkly appearance. -The Great Red Spot's side of Jupiter is busy indeed. On October 29th when Christopher Go shot this below image from the Philippines, bright orange Oval BA and the little dark red dot following it had finished passing south of (below) the Great Red Spot. Huge turbulence roils the South Equatorial Belt behind the Great Red Spot, and in the midst of this, notice the tiny dark marking next to a bright little white outbreak. -The South Temperate Belt is barely visible along some of its length but prominent elsewhere. Four white ovals dot the South South Temperate Belt. On the north (lower) side of the planet, the North Equatorial and North Temperate belts have become cleanly separated by the North Tropical Zone's return to whiteness. An extremely wide blue festoon intrudes into the bright Equatorial Zone north of the Great Red Spot.  November 1, 2012 -The bright "star" above the Moon this evening is Jupiter. Although they look close together, Jupiter is 1,500 times farther away. Aldebaran, to their right, is 930,000 times more distant than Jupiter! -Jupiter (magnitude –2.7, in Taurus) rises in the east-northeast shortly after dark, with Aldebaran to its right. Above Aldebaran are the Pleiades.  October 31, 2012 -The Halloween Moon, waning gibbous, rises around the end of twilight. The Pleiades are above it. Once it rises higher, Aldebaran sparkles is below it and bright Jupiter shines to its lower left, as shown here. Just after dark, the faint, slow-moving asteroid 35 Leukothea should occult a 10.6-magnitude star in Aquarius fairly high in the south for up to 39 seconds, for observers along a track from Florida through Michigan. October 30, 2012 -The "Summer Star" Vega is still the brightest star in the west during fall evenings. Higher above it is Deneb. Farther off to Vega's left or lower left is Altair, the third star of the Summer Triangle. -Mars (magnitude +1.2, in Ophiuchus) remains low in the southwest in evening twilight. It's upper left of similar-looking Antares; they widen from 6° to 10° apart this week. October 29, 2012 -Full Moon (exact at 3:49 p.m. Eastern Daylight Time). Look a fist-width above the Moon for the brightest stars of Aries, lined up nearly horizontally. -Algol should be at minimum light for a couple hours centered on 10:03 p.m. EDT. -Jupiter's Great Red Spot (pale orange-tan) crosses Jupiter's central meridian around 11:32 p.m. Eastern Daylight Time. October 28, 2012 -Plucked from obscurity to make astronomical history, the star 51 Pegasi will be known for all ages as the first Sun-like star discovered to host a planet beyond our solar system (in 1995). At 5th magnitude it's an easy binocular target next to the Great Square of Pegasus, even in moonlight. Can you spot it? October 27, 2012 -The bright Moon shines below the Great Square of Pegasus's bottom corner early this evening. From the Square's left corner extends a big, slightly downward line of three stars (including the corner). These form the backbone and leg of Andromeda. Dark areas can also see the Andomeda Galaxy's glow here. October 26, 2012 -The Ghost of Summer Suns. Halloween is approaching, and this means that Arcturus, the star sparkling low in the west-northwest in twilight, is taking on its role as "the Ghost of Summer Suns." What does this mean? For several days centered on October 29th every year, Arcturus occupies a special place above your local landscape. It closely marks the spot in your sky where the Sun stood at the same time, by the clock, during warm June and July — in broad daylight, of course. So, in the last days of October each year, you can think of Arcturus as the chilly Halloween ghost of the departed summer Sun. -The waxing gibbous Moon shines in the east early this evening. Look to its upper left for the Great Square of Pegasus, tipped onto one corner. October 25, 2012 -The W pattern of Cassiopeia is tipping nearly vertically high in the northeast after dusk. It stands exactly vertical around 9 p.m., depending on your location. The W's brightest side is on top. -Jupiter (magnitude –2.7, in Taurus) rises in the east-northeast around 8 or 9 p.m. daylight saving time. Once it's clear of the horizon, look for fainter orange Aldebaran to its right and Beta Tauri (Elnath) a little farther to its left. By dawn this lineup-of-three stands high and vertical in the west. October 24, 2012 -Around 8 or 9 p.m. the Big Dipper lies low and level above the north-northwest horizon. The farther north you live, the higher it will appear. If you're as far south as Miami, it's below the horizon completely. -Mars (magnitude +1.2, in Ophiuchus) is still low in the southwest in evening twilight. It's more or less above similar-looking Antares. The two are about 4° or 5° apart. October 23, 2012 -Wintry Orion sparkles above the east-southeast horizon as early as 11 p.m. now, depending on your location. Earlier in the evening, keep watch for Orion rising below or lower right of brilliant Jupiter. October 22, 2012 -Vega is the brightest star high in the west these evenings. Even higher above it is Deneb. Farther off to Vega's left or lower left is the third Summer Triangle star, Altair. -Mercury (magnitude –0.2) is having a poor evening apparition. Using binoculars, look for it 20 or 30 minutes after sundown very low in the southwest, to the lower right of Mars and Antares. October 21, 2012 -First-quarter Moon (exact at 11:32 p.m. EDT). The Moon shines in the south to southwest during evening. Look for Altair high above it as the stars come out. Later in the evening, Altair is upper right of the Moon. -The Orionid meteor shower continues into the early morning hours tonight, but the peak has since past and all that will be seen now are stragglers. You may see about 5-10 Orionids per hour. The shower's radiant point is at the top of Orion's Club, which doesn't rise high until after well midnight. The moon will still have set by the time the Orionids appear. October 20, 2012 -As twilight fades this evening, Mars and Antares are at their minimum separation of 3½°. Look for them quite low in the southwest, as shown above. -The annual Orionid meteor shower continues into the early morning hours tonight, and it should continue in the early morning hours for the next few days. You may see 10 or 20 Orionids per hour. The shower's radiant point is at the top of Orion's Club, which doesn't rise high until after well midnight. There will be no moonlight for the next few mornings. October 19, 2012 -The crescent Moon shines in the southwest as twilight fades. If it were a bow, it would be shooting an arrow to the lower right above the Mars-and-Antares pair, as shown here. Binoculars will help you pick out the two similar-looking, orange-red points. -The annual Orionid meteor shower should be getting under way in the hours before dawn Saturday morning, and it should continue in the early-morning hours for the next few days. You may see 10 or 20 Orionids per hour. The shower's radiant point is at the top of Orion's Club, which doesn't rise high until after well midnight. There will be no moonlight for the next few mornings. -At 10:48 p.m. Eastern Daylight Time, Jupiter's moon Io reappears out from behind Jupiter's eastern limb. Later, Jupiter's Great Red Spot crosses the planet's central meridian around 1:18 a.m. Saturday morning EDT (10:18 p.m. Friday evening PDT).  October 18, 2012 -The waxing crescent Moon poses over Mars and Antares low in the southwest in twilight, as shown below. -Venus (magnitude –4.0, in Leo) rises in darkness around 4 or 5 a.m. daylight saving time (depending on where you live), coming above the eastern horizon more than an hour before the first glimmer of dawn. By dawn it's shining brightly in the east. Look increasingly far above it for Regulus this week.  October 17, 2012 -Jupiter, Aldebaran, Beta Tauri, and the Hyades and Pleiades adorn the eastern sky this season, but that's not all. Below naked-eye visibility in the same area are the leading asteroids Vesta and Ceres, currently magnitudes 7.5 and 8.3, respectively. They're on their way to opposition in December. -Completely invisible between them is NASA's Dawn spacecraft, which left Vesta earlier this year and will arrive at Ceres in February 2015. October 16, 2012 -A twilight challenge: Use binoculars to look for Mercury and the hairline crescent Moon very low in the west-southwest shortly after sunset this evening, as shown here. October 15, 2012 -This is the time of year when the W shape of Cassiopeia is tipping nearly vertically in the northeast after dusk. It stands exactly vertically around 9 or 10 p.m., depending on your location. The W's brightest side is on top. -New Moon (exact at 8:03 a.m. EDT). -Mercury (magnitude –0.2) is deep in the sunset. Using binoculars, try scanning for it about 30 minutes after sundown very low in the west-southwest. Overall, this will be a poor apparition of Mercury. It stays lying low there for a month, then drops back into the Sun's glare. October 14, 2012 -Jupiter's moon Io disappears into eclipse by Jupiter's shadow, barely west of the planet, around 1:51 a.m. Monday morning EDT; 10:51 p.m. Sunday evening PDT. By then Jupiter's Great Red Spot will be nearing the planet's central meridian — which it crosses about 19 minutes later. -Mars (magnitude +1.2, in Scorpius) remains low in the southwest in evening twilight, close to twinklier orange Antares ("Anti-Mars") to its left or lower left. The gap between them shrinks from 7° to 3½° this week. They're nearly the same brightness. October 13, 2012 -Now that it's mid-October, Deneb has replaced Vega as the zenith star after dark (for skywatchers at mid-northern latitudes) — and accordingly, Capricornus is replacing Sagittarius as the most notable constellation low in the south. -Venus hangs below Leo in the morning, who is now rising from a summer sleep.  October 12, 2012 -Jupiter's Great Red Spot should cross the planet's central meridian tonight around 12:47 a.m. Saturday morning EDT. -Before dawn Saturday morning, along a path from Southern California through central Texas, the faint asteroid 371 Bohemia should occult an 8.9-magnitude star high in the sky near the Beehive Cluster in Cancer. The occultation should last up to 2 seconds. Details here: http://www.asteroidoccultation.com/2..._371_28129.htm  October 11, 2012 -Bright Arcturus is twinkling lower in the western twilight every week, riding off into the sunset for this year. How many more weeks can you follow it down? Well to its right, look for the Big Dipper lying down low. -Uranus (magnitude 5.7, at the Pisces-Cetus border) and Neptune (magnitude 7.8, in Aquarius) are in the southeast to south during evening October 10, 2012 -Jupiter's Great Red Spot should cross the planet's central meridian around 10:54 p.m. EDT. -In early dawn for the next couple mornings, watch the waning crescent Moon passing to the right of Regulus, then Venus. -Saturn is lost in the sunset. October 9, 2012 -Algol should be near minimum light for a couple hours centered on 8:21 p.m. EDT. -Jupiter (magnitude –2.6, in Taurus) rises in the east-northeast around 9 or 10 p.m. daylight saving time. Once it's clear of the horizon, look for fainter orange Aldebaran twinkling 8° to its right and Beta Tauri (Elnath) a similar distance to Jupiter's left. By dawn this lineup-of-three stands high and almost vertical in the southwest. October 8, 2012 -Even as the stars begin to come out in twilight, Cassiopeia is already higher in the northeast now than the sinking Big Dipper is in the northwest. Cassiopeia's broad W pattern is standing on end. -Mars (magnitude +1.2, in Libra) remains low in the southwest in evening twilight. Don't confuse it with twinklier orange Antares ("Anti-Mars") to its left. The gap between them shrinks from 11° to 7° this week. They're nearly the same brightness. October 7, 2012 -Vega remains very high in the west after nightfall this week. Look for fainter stars of the little constellation Lyra extending to its left, by roughly a fist-width at arm's length. -Jupiter's Great Red Spot should cross the planet's central meridian tonight around 1:25 a.m. EDT.  October 6, 2012 -The bright eclipsing variable star Algol should be in one of its periodic dimmings, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 11:32 p.m. EDT (8:32 p.m. PDT). Algol takes several additional hours to fade and to rebrighten. Click on the chart at right. -Glance up at Algol at any random time, and you have a 1 in 30 chance of catching it at least 1 magnitude fainter than normal.  October 5, 2012 -Jupiter comes up over the east-northeast horizon around 9:30 or 10 tonight, followed a half hour later by the nearly last-quarter Moon. They rise higher as night grows late, as shown at lower right. -Jupiter's satellite Ganymede slowly disappears into eclipse by Jupiter's shadow at 12:32 a.m. EDT tonight a little west of Jupiter, then emerges from eclipse at 2:31 a.m. EDT barely west of the planet's edge. Subtract 3 hours for PDT. A small telescope is all you need.  October 4, 2012 -Late this evening, look for Aldebaran below the Moon and bright Jupiter to the Moon's lower left, as shown below. October 3, 2012 -The Pleiades sparkle to the left of the waning gibbous Moon late this evening, as shown at lower right. -Jupiter (magnitude –2.5, in Taurus) rises in the east-northeast around 10 p.m. daylight saving time. Once it's clear of the horizon, look for fainter orange Aldebaran twinkling 8° to its right and Beta Tauri (Elnath) a trace farther to Jupiter's left. By the beginning of dawn, this lineup-of-three stands high and diagonal in the south. October 2, 2012 -As dawn begins to break Wednesday morning, look east for dazzling Venus. Just 0.2° from it or less (as seen from the Americas) is Regulus, less than 1% as bright. You may need binoculars to separate Regulus from Venus's glare. A telescope provides a fine view, though Venus itself is currently an undistinguished gibbous disk just 16 arcseconds in diameter. -Venus (magnitude –4.1, in Leo) rises in darkness around 4 a.m. daylight saving time (depending on where you live), emerging above the east-northeast horizon two hours before the first glimmer of dawn. By dawn it's blazing high in the east.  October 1, 2012 -Altair is the bright star high in the south at nightfall this week. Look for little Tarazed (Gamma Aquilae) to its upper right, and fainter Beta Aquilae a little farther to its lower left. Altair is just 17 light-years away. It's spinning so fast that it's a flattened ellipsoid, not a sphere. -Saturn (magnitude +0.7) is becoming lost deep in the sunset, far to the lower right of Mars. September 30, 2012 -Jupiter's Great Red Spot (currently pale orange-tan) should cross Jupiter's central meridian around 12:39 a.m. EDT tonight (9:39 p.m. PDT). -Mars (magnitude +1.2, in Libra) remains low in the southwest in evening twilight. Don't confuse it with twinklier orange Antares ("Anti-Mars") to its left or upper left. The gap between them shrinks from 16° to 11° this week. They're nearly the same brightness. September 29, 2012 -It's Harvest Moon tonight, the full Moon closest to the fall equinox (exactly full at 11:19 p.m. EDT). The Moon shines in dim Pisces this evening, below the Great Square of Pegasus. -Venus (magnitude –4.1, in Leo) rises in darkness around 4 a.m. daylight saving time (depending on where you live), emerging above the east-northeast horizon two hours before the first glimmer of dawn. By dawn it's blazing high in the east. -This week Venus is passing Regulus, which is only 1/150 as bright. They're closest on Wednesday morning October 3rd: separated by 0.2° or less before dawn in the Americas. Bring binoculars to help separate them! September 28, 2012 -High in the northeast after dark this week, the landmark constellation Cassiopeia is tilting up to stand almost on end. It's shaped like a flattened W. The brighter side of the W is on top. -Uranus is at opposition tonight. September 27, 2012 -With fall here, the bright "Spring Star" Arcturus is moving ever lower in the west after dusk. But it's got a long way to go before disappearing for the year. Look far to its right for the Big Dipper, which is now turning around to lie almost upright. -Jupiter (magnitude –2.5, in Taurus) rises in the east-northeast around 10 or 11 p.m. daylight saving time. Once it's clear of the horizon, look for fainter orange Aldebaran twinkling 8° to its right and Beta Tauri (Elnath) a trace farther to its left. By the beginning of dawn, this lineup-of-three stands high and diagonal in the south. September 26, 2012 -Look straight below the Moon, as twilight fades this evening, for Fomalhaut rising. How soon can you see it coming into view? Look way down; they're about 25° apart. The farther south you live, the earlier in twilight you can pick it up. -Saturn (magnitude +0.8, in Virgo) is sinking away into the sunset far to the lower right of Mars.  September 25, 2012 -The waxing gibbous Moon this evening shines almost midway between 1st-magnitude Altair, very high to its upper right, and 1st-magnitude Fomalhaut, about equally far to the Moon's lower left. -Mars (magnitude +1.2, in Libra) remains low in the southwest in evening twilight. Don't confuse it with twinklier orange Antares ("Anti-Mars") well to its left or upper left. The gap between them shrinks from 20° to 16° this week. September 24, 2012 -Jupiter's moon Europa reappears out of eclipse by Jupiter's shadow just off the planet's western limb at 11:48 p.m. Eastern Daylight Time, and then it slips behind the western limb 13 minutes later. September 23, 2012 -Jupiter's moon Io reappears from behind Jupiter's eastern limb at 11:39 p.m. Eastern Daylight Time. -Uranus (magnitude 5.7, at the Pisces-Cetus border) and Neptune (magnitude 7.8, in Aquarius) are well up in the southeast during evening. This week Uranus is very close to the similarly bright, but differently colored, star 44 Piscium. The two appear closest on the American evenings of Saturday and Sunday September 22nd and 23rd, when they're 1.4 arcminutes apart. Visit HERE to see if you can spot them this week, most importantly tonight! September 22, 2012 -First-quarter Moon (exact at 3:41 p.m. EDT). The Moon shines in Sagittarius, with the Sagittarius Teapot pattern to its lower left after dusk. -Sixth-magnitude Uranus is only 1.4 arcminutes from the similarly bright, but differently colored, star 44 Piscium this evening and tomorrow evening. Binoculars and a chart are all you need. They remain close all week. -The tiny black shadow of Io crosses Jupiter's face from 10:53 p.m. to 1:01 a.m. EDT tonight, followed by Io itself from 12:10 to 2:18 a.m. Eastern Daylight Time. Remember that Jupiter doesn't rise until around 10 or 11 p.m. in your local daylight time. -Autumn begins in the Northern Hemisphere (spring in the Southern Hemisphere) at the equinox, 10:49 a.m. EDT. This is when the center of the Sun crosses the equator heading south for the year. Today the Sun rises and sets nearly at the east and west points on your horizon. September 21, 2012 -Since 1844, deep-sky observers have known the open star cluster M11 (off the tail of Aquila) as the Wild Duck Cluster. But where exactly are the ducks? It is located in the beautiful Scutum star cloud, surrounded by one of the most dense star fields in the sky. Many clusters would be lost in such star studded glory, but M11 stands out clearly. According to Burnham's it was Rev. Wm. Derham of England who first resolved the cluster into stars in 1732. It was Admiral Smyth who noted that the main group of brighter stars resemble "a flight of wild ducks." Burnham's describes M11 as an "Exceptionally fine galactic star cluster, lying on the north edge of the prominent Scutum Star Cloud, and one of the outstanding objects of its type for telescopes of moderate aperture." Many of the stars are brighter than 11th magnitude, making for a terrific view in even a 6-inch scope. In smaller instruments or binoculars M11 appears as a hazy spot as bright as a 6th magnitude star and can even be glimpsed as such to the naked eye from a dark location. The first stars to resolve will be those that form a triangular structure - Smyth's wild ducks. A 10-inch scope will reveal at least 500 stars here splashed about in spectacular fashion.  September 20, 2012 -This evening the Moon marks the way to Mars-like Antares, twinkling to its lower left as shown above. -Antares and Scorpius are already sinking at sunset into the horizon after sunset as the milky way is at its highest point.  September 19, 2012 -Look much closer right of the Moon this evening in twilight for little Mars, as shown below (for North America). The Moon occults (covers) Mars for parts of central and southern South America before sunset. -More information on the lunar occultation can be found here: http://earthsky.org/tonight/moon-nea...n-september-19 September 18, 2012 -Look very low in the west-southwest in early twilight for the slender crescent Moon. Well to the Moon's right, Saturn is departing for the season, as shown above (for North America). -Mars and Saturn (magnitudes +1.2 and +0.8) are low in the southwest and west-southwest, respectively, after sunset. They're now about 20° apart. Use binoculars to help find them in early twilight before they sink too low. Mars begins the week just 1° below Alpha Librae, a wide binocular double star of magnitudes 3 and 5. By Tuesday September 18th, Mars is 2½° left of the star pair. September 17, 2012 -As summer prepares to give way to fall (at the equinox on September 22nd), Vega prepares to give way to Deneb as the bright zenith star when night descends. This is also when Altair is crossing its own highest point due south. September 16, 2012 -The bright eclipsing variable star Algol is now high in the northeast by 9 or 10 p.m. local daylight-saving time. Algol should be at its minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 9:51 p.m. Eastern Daylight Time. It takes several additional hours to fade and to rebrighten. September 15, 2012 -With summer nearing its end, the Teapot of Sagittarius has moved over to the south-southwest right after dark, tilting to the right as if to pour out the last of summer. -New Moon (exact at 10:11 p.m. EDT). September 14, 2012 -As the Great Square of Pegasus rises high in the east these evenings, the Big Dipper is swinging down low in the northwest as if carrying water. To see the Dipper at its very lowest due north, you'll have to stay up till 2 a.m. daylight-saving time. Come December it'll be there at dusk. September 13, 2012 -Venus (magnitude –4.3, in Cancer) rises in darkness around 3 a.m. daylight saving time (depending on where you live), emerging above the east-northeast horizon a good two hours before the first glimmer of dawn. By early dawn it's blazing high in the east. Binoculars show the Beehive star cluster 6° to Venus's lower left on the morning of the 8th, closing to less than 3° to Venus's left by the 12th and 13th.  September 12, 2012 -Jupiter (magnitude –2.4, in Taurus) rises in the east-northeast around 11 or midnight daylight saving time. Once it's well clear of the horizon, look for fainter orange Aldebaran twinkling 7° to its right, and Beta Tauri a bit farther to Jupiter's left. By dawn this line of three stands very high in the south. -Uranus (magnitude 5.7, at the Pisces-Cetus border) and Neptune (magnitude 7.8, in Aquarius) reach good heights in the southeast by mid-evening. September 11, 2012 -Before and during dawn Wednesday morning, Venus shines left of the waning crescent Moon, as shown here. They're 4° or 5° apart at the times of dawn for North America. Also spot Procyon farther to their right (outside the frame here). And before the sky brightens too much, binoculars show the Beehive star cluster 3° to Venus's left. September 10, 2012 -Equally bright as Vega overhead is Arcturus sinking in the west. Look a third of the way up from Arcturus to Vega for the dim semicircle of Corona Borealis, the Northern Crown, with its one moderately bright star, Alphecca. Look two thirds of the way up for the dim Keystone of Hercules. -Venus (magnitude –4.3, in Cancer) rises in darkness around 3 a.m. daylight saving time (depending on where you live), emerging above the east-northeast horizon a good two hours before the first glimmer of dawn. By early dawn it's blazing high in the east. -Binoculars show the Beehive star cluster 4.5° to Venus's lower left on the morning of the 10th, closing to less than 3° to Venus's left by the 12th and 13th. September 9, 2012 -This is the time of year when bright Vega shines closest to the zenith as the stars come out at dusk. Vega goes right through your zenith if you're at latitude 39° north (Baltimore, Kansas City, Lake Tahoe). -Mars and Saturn (magnitudes +1.2 and +0.8) are low in the southwest and west-southwest, respectively, as evening twilight fades. This week they widen from 13° to 17° apart. Look for them well to the lower left of brighter Arcturus in the west. Can you still find Spica twinkling under Saturn? Mars ends the week just 1° below Alpha Librae, a wide binocular double star.  September 8, 2012 -It's still summer, but look low in the southeast this week after about 9 p.m. (depending on where you live) and there's 1st-magnitude Fomalhaut, the Autumn Star, already making its seasonal appearance. September 7, 2012 -Jupiter and the last-quarter Moon rise together around 11 or midnight, depending on where you live. Watch for them coming over the east-northeast horizon, and look for fainter Aldebaran to their right. They continue climbing high up the sky until dawn Saturday morning the 8th, as seen here. September 6, 2012 -Whenever Vega is near the zenith, as it is just after dark now, you know Sagittarius is at its highest and best in the south — displaying the deep-sky riches of the summer Milky Way to their best advantage. The Teapot asterism of Sagittarius is tilting to pour to the right. The richest big patch of the Milky Way, the Large Sagittarius Star Cloud, is just above its spout. September 5, 2012 -One of the nicest star clusters for binoculars or a telescope is M11 in Scutum just off the tail of Aquila, the Eagle, as most amateur astronomers know. But can you also spot dimmer, more difficult M26 less than 4° below it? -Jupiter (magnitude –2.3, in Taurus) rises in the east-northeast around 11 or midnight daylight saving time. Once it's well clear of the horizon, look for fainter orange Aldebaran twinkling 6° or 7° to its right. By dawn Jupiter shines very high in the south-southeast, 40° or 45° upper right of brighter Venus. September 4, 2012 -Face south soon after dark and look high. The brightest star there is Altair, with dimmer Tarazed a finger-width at arm's length above it and a bit to the right. Look left of Altair, by a bit more than a fist-width, for the dim but distinctive little constellation Delphinus, the Dolphin, splashing in the edge of the Milky Way. September 3, 2012 -As twilight fades, spot bright Arcturus high in the west. Look far to its lower left for Saturn and Mars. They're about a fist-width at arm's length apart. Mars is the one on the left. -Compare Mars with similarly bright and similarly colored Antares ("Anti-Mars" in Greek), three fists to its left and perhaps higher. Which of the two looks deeper orange? September 2, 2012 -The waning gibbous Moon rises in late twilight. It's beneath the uptilted Great Square of Pegasus. -Mars (magnitude +1.2, in Libra) and Saturn (magnitude +0.8, in Virgo) are low in the west-southwest in twilight. This week they widen from 10° to 13° apart: a fist-width at arm's length or more. Look for them far lower left of bright Arcturus. Saturn is the one on the right. You may still be able to see Spica twinkling 5° below Saturn. September 1, 2012 -Bright Vega passes the zenith as twilight fades away — if you live in the world's mid-northern latitudes. Vega goes right through your zenith if you're at north latitude 39°: near the latitudes of Baltimore, Kansas City, Lake Tahoe, Sendai, Beijing, Athens, Lisbon.
-Mercury is lost low in the glow of sunrise. Astro Pic of the Day Archive September 1, 2012 - February 28, 2013 February 28, 2013  The alarmingly tall inhabitants of this small, snowy planet cast long shadows in bright moonlight. Of course, the snowy planet is actually planet Earth and the wide-angle mosaic, shown as a little planet projection, was recorded on February 25 during the long northern night of the Full Snow Moon. The second brightest celestial beacon is Jupiter, on the right above the little planet's horizon. Lights near Östersund, Sweden glow along the horizon, surrounding the snow covered lake Storsjön. The photographer reports that the journey out onto the frozen lake by sled to capture the evocative Full Snow Moon scene was accompanied by ice sounds, biting cold, and a moonlit mist. February 27, 2013  What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Known informally as Undulatus asperatus clouds, they can be stunning in appearance, unusual in occurrence, are relatively unstudied, and have even been suggested as a new type of cloud. Whereas most low cloud decks are flat bottomed, asperatus clouds appear to have significant vertical structure underneath. Speculation therefore holds that asperatus clouds might be related to lenticular clouds that form near mountains, or mammatus clouds associated with thunderstorms, or perhaps a foehn wind - a type of dry downward wind that flows off mountains. Such a wind called the Canterbury arch streams toward the east coast of New Zealand's South Island. The above image, taken above Hanmer Springs in Canterbury, New Zealand, in 2005, shows great detail partly because sunlight illuminates the undulating clouds from the side. February 26, 2013 Does it rain on the Sun? Yes, although what falls is not water but extremely hot plasma. An example occurred in mid-July 2012 after an eruption on the Sun that produced both a Coronal Mass Ejection and a moderate solar flare. What was more unusual, however, was what happened next. Plasma in the nearby solar corona was imaged cooling and falling back, a phenomenon known as coronal rain. Because they are electrically charged, electrons, protons, and ions in the rain were gracefully channeled along existing magnetic loops near the Sun's surface, making the scene appear as a surreal three-dimensional sourceless waterfall. The resulting surprisingly-serene spectacle is shown in ultraviolet light and highlights matter glowing at a temperature of about 50,000 Kelvin. Each second in the above time lapse video takes about 6 minutes in real time, so that the entire coronal rain sequence lasted about 10 hours. February 25, 2013 -Full Moon this evening (exactly full at 3:26 p.m. EST). The Moon is south of Leo: in the dim constellation Sextans for part of the night. -Saturn (magnitude +0.5, in Libra) rises in the east-southeast around 11 p.m. Watch for it to come up well to the lower left of Spica and farther to the lower right of brighter Arcturus. Saturn shines highest in the south before dawn — more or less between Spica to its right and Antares farther to its lower left. February 24, 2013  The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on the sky. The above image is a digital combination of a ground-based image from the 0.9-meter telescope at Kitt Peak National Observatory and a space-based image from the Hubble Space Telescope highlighting sharp features normally too red to be seen. Anyone with a good pair of binoculars, however, can see this Whirlpool toward the constellation of the Hunting Dogs (Canes Venatici. M51 is a spiral galaxy of type Sc and is the dominant member of a whole group of galaxies. Astronomers speculate that M51's spiral structure is primarily due to its gravitational interaction with a smaller galaxy just off the top of the image. February 23, 2013  A meteoroid fell to Earth on February 15, streaking some 20 to 30 kilometers above the city of Chelyabinsk, Russia at 9:20am local time. Initially traveling at about 20 kilometers per second, its explosive deceleration after impact with the lower atmosphere created a flash brighter than the Sun. This picture of the brilliant bolide (and others of its persistent trail) was captured by photographer Marat Ametvaleev, surprised during his morning sunrise session creating panoramic images of the nearby frosty landscape. An estimated 500 kilotons of energy was released by the explosion of the 17 meter wide space rock with a mass of 7,000 to 10,000 tons. Actually expected to occur on average once every 100 years, the magnitude of the Chelyabinsk event is the largest known since the Tunguska impact in 1908. February 22, 2013  This remarkable self-portrait of NASA's Mars Curiosity Rover includes a sweeping panoramic view of its current location in the Yellowknife Bay region of the Red Planet's Gale Crater. The rover's flat, rocky perch, known as "John Klein", served as the site for Curiosity's first rock drilling activity. At the foot of the proud looking rover, a shallow drill test hole and a sample collection hole are 1.6 centimeters in diameter. The impressive mosaic was constructed using frames from the rover's Mars Hand Lens Imager (MAHLI) and Mastcam. Used to take in the panoramic landscape frames, the Mastcam is standing high above the rover's deck. But MAHLI, intended for close-up work, is mounted at the end of the rover's robotic arm. The MAHLI frames used to create Curiosity's self-portrait exclude sections that show the arm itself and so MAHLI and the robotic arm are not seen. Check out this spectacular interactive version of Curiosity's self-portrait panorama. February 21, 2013  How would you change the course of an Earth-threatening asteroid? One possibility - a massive spacecraft that uses gravity as a towline - is illustrated in this artist's vision of a gravitational tractor in action. In the hypothetical scenario worked out in 2005 by Edward Lu and Stanley Love at NASA's Johnson Space Center, a 20 ton nuclear-electric spacecraft tows a 200 meter diameter asteroid by simply hovering near the asteroid. The spacecraft's ion drive thrusters are canted away from the surface. Their slight but steady thrust would gradually and predictably alter the course of the tug and asteroid, coupled by their mutual gravitational attraction. While it sounds like the stuff of science fiction, ion drives do power existing spacecraft. One advantage of using a gravitational tractor is that it would work regardless of the asteroid's structure. Given sufficient warning and time, a gravitational tractor could deflect the path of an asteroid known to be on a collision course enough to miss planet Earth. February 20, 2013  Why would clouds form a hexagon on Saturn? Nobody is sure. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it anywhere else in the Solar System. If Saturn's South Pole wasn't strange enough with its rotating vortex, Saturn's North Pole might be considered even stranger. The bizarre cloud pattern is shown above in great detail by a recent image taken by the Saturn-orbiting Cassini spacecraft. This and similar images show the stability of the hexagon even 20+ years after Voyager. Movies of Saturn's North Pole show the cloud structure maintaining its hexagonal structure while rotating. Unlike individual clouds appearing like a hexagon on Earth, the Saturn cloud pattern appears to have six well defined sides of nearly equal length. Four Earths could fit inside the hexagon. Imaged from the side, the dark shadow of the Jovian planet is seen eclipsing part of its grand system of rings, partly visible on the upper right. February 19, 2013  Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing the Sun, Mercury will be visible low on the horizon for only a short while after sunset. If leading the Sun, Mercury will be visible only shortly before sunrise. So at certain times of the year an informed skygazer with a little determination can usually pick Mercury out from a site with an unobscured horizon. Above, a lot of determination has been combined with a little digital manipulation to show Mercury's successive positions during March of 2000. Each picture was taken from the same location in Spain when the Sun itself was 10 degrees below the horizon and superposed on the single most photogenic sunset. Currently, Mercury is visible in the western sky after sunset, but will disappear in the Sun's glare after a few days. February 18, 2013 Where is the Pelican Nebula? Today, thanks to inventive digital manipulations of Filipe Alves, it is possible to show you exactly where the photogenic Pelican Nebula can be found. Today's picture of the day is a spectacular movie that zooms from the perspective of an unaided human eye to that of a powerful telescope. The observatory dome visible on the right is part of Calar Alto Observatory in southern Spain. The image zooms into the constellation of Cygnus, passes the greater Pelican Nebula (IC 5070), and settles on a dust structure in the Pelican head housing unborn stars. February 17, 2013 Source: There it goes. That small spot moving in front of background stars in the above video is a potentially dangerous asteroid passing above the Earth's atmosphere. This past Friday, the 50-meter wide asteroid 2012 DA14 just missed the Earth, passing not only inside the orbit of the Moon, which is unusually close for an asteroid of this size, but also inside the orbit of geosynchronous satellites. Unfortunately, asteroids this big or bigger strike the Earth every 1000 years or so. Were 2012 DA14 to have hit the Earth, it could have devastated a city-sized landscape, or stuck an ocean and raised dangerous tsunamis. Although finding and tracking potentially dangerous asteroids is a primary concern of modern astronomy, these small bodies or ice and rock are typically so dim that only a few percent of them have been found, so far. Even smaller chunks of ice and rock, like the (unrelated) spectacular meteors that streaked over Russia and California over the past few days, are even harder to find - but pose less danger. February 16, 2013  For now, Comet Lemmon (C/2012 F6a), and Comet PanSTARRS (C/2011 L4) are sweeping through southern skies. Lemmon's lime green coma and thin tail are near the left edge of this telephoto scene, a single frame from a timelapse video (vimeo here) recorded on February 12, tracking its motion against the background stars. Comet Lemmon's path brought it close to the line-of-sight to prominent southern sky treasures the Small Magellanic Cloud and globular cluster 47 Tucanae (right). Sporting a broader, whitish tail, Comet PanSTARRS appears in later video frames moving through the faint constellation Microscopium. Visible in binoculars and small telescopes, both comets are getting brighter and headed toward northern skies in coming months. February 15, 2013  Two dark shadows loom across the banded and mottled cloud tops of Jupiter in this sharp telescopic view. In fact, captured on January 3rd, about a month after the ruling gas giant appeared at opposition in planet Earth's sky, the scene includes the shadow casters. Visible in remarkable detail at the left are the large Galilean moons Ganymede (top) and Io. With the two moon shadows still in transit, Jupiter's rapid rotation has almost carried its famous Great Red Spot (GRS) around the planet's limb from the right. The pale GRS was preceded by the smaller but similar hued Oval BA, dubbed Red Spot Jr., near top center. North is down in the inverted image. February 14, 2013  On another Valentine's Day (February 14, 1990), cruising four billion miles from the Sun, the Voyager 1 spacecraft looked back to make this first ever family portrait of our Solar System. The complete portrait is a 60 frame mosaic made from a vantage point 32 degrees above the ecliptic plane. In it, Voyager's wide angle camera frames sweep through the inner Solar System at the left, linking up with gas giant Neptune, at the time the Solar System's outermost planet, at the far right. Positions for Venus, Earth, Jupiter, Saturn, Uranus, and Neptune are indicated by letters, while the Sun is the bright spot near the center of the circle of frames. The inset frames for each of the planets are from Voyager's narrow field camera. Unseen in the portrait are Mercury, too close to the Sun to be detected, and Mars, unfortunately hidden by sunlight scattered in the camera's optical system. Small, faint Pluto's position was not covered. February 13, 2013  The Great Nebula in Orion is a intriguing place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. But this image, an illusory-color composite of four colors of infrared light taken with the Earth orbiting WISE observatory, shows the Orion Nebula to be a bustling neighborhood or recently formed stars, hot gas, and dark dust. The power behind much of the Orion Nebula (M42) is the stars of the Trapezium star cluster, seen near the center of the above wide field image. The eerie green glow surrounding the bright stars pictured here is their own starlight reflected by intricate dust filaments that cover much of the region. The current Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next 100,000 years. February 12, 2013   Some auroras can only be seen with a camera. They are called subvisual and are too faint to be seen with the unaided eye. In the above image, the green aurora were easily visible to the eye, but the red aurora only became apparent after a 20-second camera exposure. The reason is that the human eye only accumulates light for a fraction of a second at a time, while a camera shutter can be left open much longer. When photographing an already picturesque scene near Anchorage, Alaska, USA, last autumn, a camera caught both the visual green and subvisual red aurora reflected in a lily pad-covered lake. High above, thousands of stars were visible including the Pleiades star cluster, while the planet Jupiter posed near the horizon, just above clouds, toward the image right. Auroras are caused by energetic particles from the Sun impacting the Earth's magnetosphere, causing electrons and protons to rain down near the Earth's poles and impact the air. Both red and green aurora are typically created by excited oxygen atoms, with red emission, when visible, dominating higher up. Auroras are known to have many shapes and colors. February 11, 2013  Massive stars, abrasive winds, mountains of dust, and energetic light sculpt one of the largest and most picturesque regions of star formation in the Local Group of Galaxies. Known as N11, the region is visible on the upper right of many images of its home galaxy, the Milky Way neighbor known as the Large Magellanic Clouds (LMC). The above image was taken for scientific purposes by the Hubble Space Telescope and reprocessed for artistry by an amateur to win the Hubble's Hidden Treasures competition. Although the section imaged above is known as NGC 1763, the entire N11 emission nebula is second in LMC size only to 30 Doradus. Studying the stars in N11 has shown that it actually houses three successive generations of star formation. Compact globules of dark dust housing emerging young stars are also visible around the image. February 10, 2013  The first identified compact galaxy group, Stephan's Quintet is featured in this stunning image from the newly upgraded Hubble Space Telescope. About 300 million light-years away, only four galaxies of the group are actually locked in a cosmic dance of repeated close encounters. The odd man out is easy to spot, though. The four interacting galaxies (NGC 7319, 7318A, 7318B, and 7317) have an overall yellowish cast and tend to have distorted loops and tails, grown under the influence of disruptive gravitational tides. But the bluish galaxy at the upper left (NGC 7320) is much closer than the others. A mere 40 million light-years distant, it isn't part of the interacting group. In fact, individual stars in the foreground galaxy can be seen in the sharp Hubble image, hinting that it is much closer than the others. Stephan's Quintet lies within the boundaries of the high flying constellation Pegasus. February 9, 2013  One hundred years ago today the Great Meteor Procession of 1913 occurred, a sky event described by some as "magnificent" and "entrancing" and which left people feeling "spellbound" and "privileged". Because one had to be in a right location, outside, and under clear skies, only about 1,000 people noted seeing the procession. Lucky sky gazers - particularly those near Toronto, Canada - had their eyes drawn to an amazing train of bright meteors streaming across the sky, in groups, over the course of a few minutes. A current leading progenitor hypothesis is that a single large meteor once grazed the Earth's atmosphere and broke up. When the resulting pieces next encountered the Earth, they came in over south-central Canada, traveled thousands of kilometers as they crossed over the northeastern USA, and eventually fell into the central Atlantic ocean. Pictured above is a digital scan of a halftone hand-tinted image by the artist Gustav Hahn who was fortunate enough to witness the event first hand. Although nothing quite like the Great Meteor Procession of 1913 has been reported since, numerous bright fireballs - themselves pretty spectacular - have since been recorded, some even on video. Such as this one in 1992 which hit a car, shown below:  February 8, 2013  Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small galaxies form stars too, like nearby NGC 6822, also known as Barnard's Galaxy. Beyond the rich starfields in the constellation Sagittarius, NGC 6822 is a mere 1.5 million light-years away, a member of our Local Group of galaxies. About 7,000 light-years across, the dwarf irregular galaxy is seen to be filled with young blue stars and mottled with the telltale pinkish hydrogen glow of star forming regions in the deep color composite image. Contributing to the science of LITTLE THINGS, this portrait of a small galaxy was made as part of the Lowell Amateur Research Initiative (LARI), welcoming collaborations with amateur astronomers. More info on LITTLE THINGS here. February 7, 2013  Currently sweeping through southern skies, Comet Lemmon (C/2012 F6) was named for its discovery last year as part of the Mount Lemmon (Arizona) Survey. Brighter than expected but still just below naked-eye visibility, Comet Lemmon sports a stunning lime green coma and faint divided tail in this telescopic image from February 4. The greenish tint comes from the coma's diatomic C2 gas fluorescing in sunlight. Captured from an observatory near Sydney, Australia, the color composite is constructed from a series of individual exposures registered on the comet. Across the 1 degree wide field of view, the star trails are a consequence of the comet's relatively rapid motion against the background of stars near the South Celestial Pole. Moving north, the comet should grower brighter, reaching a peak (3rd magnitude or so) when it is closest to the Sun in late March. By early April it should be visible from the northern hemisphere. Of course, this year Comet Lemmon may be just another pretty comet as skygazers on planet Earth also eagerly anticipate views of Comet PANSTARRS and Comet ISON. February 6, 2013  The spiral arms of bright galaxy M106 sprawl through this remarkable multiframe portrait, composed of data from ground- and space-based telescopes. Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici. The well-measured distance to M106 is 23.5 million light-years, making this cosmic scene about 80,000 light-years across. Typical in grand spiral galaxies, dark dust lanes, youthful blue star clusters, and pinkish star forming regions trace spiral arms that converge on the bright nucleus of older yellowish stars. But this detailed composite reveals hints of two anomalous arms that don't align with the more familiar tracers. Seen here in red hues, sweeping filaments of glowing hydrogen gas seem to rise from the central region of M106, evidence of energetic jets of material blasting into the galaxy's disk. The jets are likely powered by matter falling into a massive central black hole. February 5, 2013  What if you saw your shadow on Mars and it wasn't human? Then you might be the robotic Curiosity rover currently exploring Mars. Curiosity landed in Gale Crater last August and has been busy looking for signs of ancient running water and clues that Mars could once have harbored life. Pictured above, Curiosity has taken a wide panorama that includes its own shadow in the direction opposite the Sun. The image was taken in November from a location dubbed Point Lake, although no water presently exists there. Curiosity has already discovered several indications of dried streambeds on Mars, and is scheduled to continue its exploration by climbing nearby Mt. Sharp over the next few years. February 4, 2013 Source: Namibia has some of the darkest nights visible from any continent. It is therefore home to some of the more spectacular skyscapes, a few of which have been captured in the above time-lapse video. Visible at the movie start are unusual quiver trees perched before a deep starfield highlighted by the central band of our Milky Way Galaxy. This bright band of stars and gas appears to pivot around the celestial south pole as our Earth rotates. The remains of camel thorn trees are then seen against a sky that includes a fuzzy patch on the far right that is the Large Magellanic Cloud, a small satellite galaxy to the Milky Way. A bright sunlight-reflecting satellite passes quickly overhead. Quiver trees appear again, now showing their unusual trunks, while the Small Magellanic Cloud becomes clearly visible in the background. Artificial lights illuminate a mist that surround camel thorn trees in Deadvlei. In the final sequence, natural Namibian stone arches are captured against the advancing shadows of the setting moon. This video incorporates over 16,000 images shot over two years, and won top honors among the 2012 Travel Photographer of the Year awards. February 3, 2013  This esthetic close-up of cosmic clouds and stellar winds features LL Orionis, interacting with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged Sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed. The small, arcing, graceful structure just above and left of center is LL Ori's cosmic bow shock, measuring about half a light-year across. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the upper left corner of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. The beautiful picture is part of a large mosaic view of the complex stellar nursery in Orion, filled with a myriad of fluid shapes associated with star formation. February 2, 2013  Beyond a fertile field of satellite communication antennas at Kennedy Space Center, an Atlas V rocket streaks into orbit in this long exposure photograph. In the thoughtfully composed image recorded on the evening of January 30, the antennas in the foreground bring to mind the rocket's payload, a Tracking and Data Relay Satellite (TDRS; sounds like TEE-dress). This TDRS-K is the first in a next-generation series adding to the constellation of NASA's communication satellites. Operating from geosynchronous orbit 22,300 miles (36,000 kilometers) above planet Earth, the network of TDRS satellites relays communications, data, and commands between spacecraft and ground stations. Formerly the TDRS network provided communications for space shuttle missions. In fact, many TDRS satellites were ferried as far as low Earth orbit on space shuttles. The TDRS network continues to support major spacecraft like the International Space Station, the Hubble Space Telescope, and the Fermi Gamma-ray Space Telescope. February 1, 2013  Beyond a fertile field of satellite communication antennas at Kennedy Space Center, an Atlas V rocket streaks into orbit in this long exposure photograph. In the thoughtfully composed image recorded on the evening of January 30, the antennas in the foreground bring to mind the rocket's payload, a Tracking and Data Relay Satellite (TDRS; sounds like TEE-dress). This TDRS-K is the first in a next-generation series adding to the constellation of NASA's communication satellites. Operating from geosynchronous orbit 22,300 miles (36,000 kilometers) above planet Earth, the network of TDRS satellites relays communications, data, and commands between spacecraft and ground stations. Formerly the TDRS network provided communications for space shuttle missions. In fact, many TDRS satellites were ferried as far as low Earth orbit on space shuttles. The TDRS network continues to support major spacecraft like the International Space Station, the Hubble Space Telescope, and the Fermi Gamma-ray Space Telescope. January 31, 2013  The delightful Dark Doodad Nebula drifts through southern skies, a tantalizing target for binoculars in the constellation Musca, The Fly. The dusty cosmic cloud is seen against rich starfields just south of the prominent Coalsack Nebula and the Southern Cross. Stretching for about 3 degrees across this scene the Dark Doodad seems punctuated at its southern tip (lower left) by globular star cluster NGC 4372. Of course NGC 4372 roams the halo of our Milky Way Galaxy, a background object some 20,000 light-years away and only by chance along our line-of-sight to the Dark Doodad. The Dark Doodad's well defined silhouette belongs to the Musca molecular cloud, but its better known alliterative moniker was first coined by astro-imager and writer Dennis di Cicco in 1986 while observing comet Halley from the Australian outback. The Dark Doodad is around 700 light-years distant and over 30 light-years long. January 30, 2013  Has a new planet been discovered? What is pictured above is a remarkable 24 hour mosaic surrounding a spot on Sounio, Greece, right here on planet Earth. Images taken at night compose the top half of the picture, with star trails lasting as long as 11 hours visible. Contrastingly, images taken during the day compose the bottom of the image, with the Sun being captured once every 15 minutes. The image center shows a Little Prince wide angle projection centered on the ground but including gravel, grass, trees, Saint John's church, clouds, crepuscular rays, and even a signature icon of the photographer - the Temple of Poseidon. Meticulous planning as well as several transition shots and expert digital processing eventually culminated in this image documenting half of the final two days of last year. January 29, 2013 What would it be like to drive on the Moon? You don't have to guess - humans have actually done it. Pictured above, Apollo 16 astronauts John Young and Charles Duke recorded video during one such drive in 1972, with a digital version now available on the web. No matter which direction it headed, the Lunar Rover traveled a path literally covered with rocks and craters. The first half of the above video shows the rover zipping about a moonscape near 10 kilometers per hour, while the second half shows a dash-cam like view. The Lunar Rover was deployed on the later Apollo missions as a way for astronauts to reach and explore terrain further from the Lunar Module basecamp than was possible by walking in cumbersome spacesuits. Possible future lunar missions that might deploy robotic rovers capable of beaming back similar videos include those by China, Russia, India, and Google X-Prize contestants. January 28, 2013  Clouds of glowing gas mingle with dust lanes in the Trifid Nebula, a star forming region toward the constellation of the Archer (Sagittarius). In the center, the three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the right, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, also known as M20, is only about 300,000 years old, making it among the youngest emission nebulae known. The nebula lies about 9,000 light years away and the part pictured here spans about 10 light years. The above image is a composite with luminance taken from an image by the 8.2-m ground-based Subaru Telescope, detail provided by the 2.4-m orbiting Hubble Space Telescope, color data provided by Martin Pugh and image assembly and processing provided by Robert Gendler. January 27, 2013  Comet McNaught of 2007 has been, so far, the most photogenic comet of our time. After making quite a show in the northern hemisphere in early 2007 January, the comet moved south and developed a long and unusual dust tail that dazzled southern hemisphere observers. In this image, Comet McNaught was captured above Santiago, Chile. The bright comet dominates on the left while part of its magnificent tail spreads across the entire frame. From this vantage point in the Andes Mountains, one looks up toward Comet McNaught and a magnificent sky, across at a crescent moon, and down on clouds, atmospheric haze, and the city lights. The current year 2013 holds promise to be even better for comets than 2007. In early March, Comet PANSTARRS is on track to become visible to the unaided eye, while at the end of the year Comet ISON shows possibilities that include casting a tail that spreads across the sky, breaking up, and even becoming one of the brightest comets in recorded history. January 26, 2013  Moonlight illuminates a snowy scene in this night land and skyscape made on January 17 from Lower Miller Creek, Alaska, USA. Overexposed near the mountainous western horizon is the first quarter Moon itself, surrounded by an icy halo and flanked left and right by moondogs. Sometimes called mock moons, a more scientific name for the luminous apparations is paraselenae (plural). Analogous to a sundog or parhelion, a paraselene is produced by moonlight refracted through thin, hexagonal, plate-shaped ice crystals in high cirrus clouds. As determined by the crystal geometry, paraselenae are seen at an angle of 22 degrees or more from the Moon. Compared to the bright lunar disk, paraselenae are faint and easier to spot when the Moon is low. January 25, 2013  On January 25 (UT) 2004, the Opportunity rover fell to Mars, making today the 9th anniversary of its landing. After more than 3,200 sols (Mars solar days) the golf cart-sized robot from Earth is still actively exploring the Red Planet, though its original mission plan was for three months. Having driven some 35 kilometers (22 miles) from its landing site, Opportunity's panoramic camera recorded the segments of this scene, in November and December of last year. The digitally stitched panorama spans more than 210 degrees across the Matijevic Hill area along the western rim of Endeavour Crater. Features dubbed Copper Cliff, a dark outcrop, appear at the left, and Whitewater Lake, a bright outcrop, at the far right. The image is presented here in a natural color approximation of what the scene would look like to human eyes. January 24, 2013  Clouds on a summer night frame this sea and skyscape, recorded earlier this month near Buenos Aires, Argentina. But planet Earth's clouds are not the only clouds on the scene. Starry clouds and nebulae along the southern hemisphere's summer Milky Way arc above the horizon, including the dark Coal Sack near the Southern Cross and the tantalizing pinkish glow of the Carina Nebula. Both the Large (top center) and Small Magellanic Clouds are also in view, small galaxies in their own right and satellites of the Milky Way up to 200,000 light-years distant. Alpha star of the Carina constellation and second brightest star in Earth's night, Canopus shines above about 300 light-years away. Still glinting in sunlight at an altitude of 400 kilometers, the orbiting International Space Station traces a long streak through the single, 5 minute, star-tracking exposure. January 23, 2013  Large spiral galaxy NGC 4945 is seen edge-on near the center of this cosmic galaxy portrait. In fact, NGC 4945 is almost the size of our own Milky Way Galaxy. Its own dusty disk, young blue star clusters, and pink star forming regions standout in the sharp, colorful telescopic image. About 13 million light-years distant toward the expansive southern constellation Centaurus, NGC 4945 is only about six times farther away than Andromeda, the nearest large spiral galaxy to the Milky Way. Though the galaxy's central region is largely hidden from view for optical telescopes, X-ray and infrared observations indicate significant high energy emission and star formation in the core of NGC 4945. Its obscured but active nucleus qualifies the gorgeous island universe as a Seyfert galaxy and likely home to a central supermassive black hole. January 22, 2013  The North America nebula on the sky can do what the North America continent on Earth cannot - form stars. Specifically, in analogy to the Earth-confined continent, the bright part that appears as Central America and Mexico is actually a hot bed of gas, dust, and newly formed stars known as the Cygnus Wall. The above image shows the star forming wall lit and eroded by bright young stars, and partly hidden by the dark dust they have created. The part of the North America nebula (NGC 7000) shown spans about 15 light years and lies about 1,500 light years away toward the constellation of the Swan (Cygnus). January 21, 2013  What is it? It was found at the bottom of the sea aboard an ancient Greek ship. Its seeming complexity has prompted decades of study, although some of its functions remained unknown. X-ray images of the device have confirmed the nature of the Antikythera mechanism, and discovered several surprising functions. The Antikythera mechanism has been discovered to be a mechanical computer of an accuracy thought impossible in 80 BC, when the ship that carried it sank. Such sophisticated technology was not thought to be developed by humanity for another 1,000 years. Its wheels and gears create a portable orrery of the sky that predicted star and planet locations as well as lunar and solar eclipses. The Antikythera mechanism, shown above, is 33 centimeters high and therefore similar in size to a large book. January 20, 2013   Gazing out from within the Milky Way, our own galaxy's true structure is difficult to discern. But an ambitious survey effort with the Spitzer Space Telescope now offers convincing evidence that we live in a large galaxy distinguished by two main spiral arms (the Scutum-Centaurus and Perseus arms) emerging from the ends of a large central bar. In fact, from a vantage point that viewed our galaxy face-on, astronomers in distant galaxies would likely see the Milky Way as a two-armed barred spiral similar to this artist's illustration. Previous investigations have identified a smaller central barred structure and four spiral arms. Astronomers still place the Sun about a third of the way in from the Milky Way's outer edge, in a minor arm called the Orion Spur. January 19, 2013  A gaze across a cosmic skyscape, this telescopic mosaic reveals the continuous beauty of things that are. The evocative scene spans some 6 degrees or 12 Full Moons in planet Earth's sky. At the left, folds of red, glowing gas are a small part of an immense, 300 light-year wide arc. Known as Barnard's loop, the structure is too faint to be seen with the eye, shaped by long gone supernova explosions and the winds from massive stars, and still traced by the light of hydrogen atoms. Barnard's loop lies about 1,500 light-years away roughly centered on the Great Orion Nebula, a stellar nursery along the edge of Orion's molecular clouds. But beyond lie other fertile star fields in the plane of our Milky Way Galaxy. At the right, the long-exposure composite finds NGC 2170, a dusty complex of nebulae near a neighboring molecular cloud some 2,400 light-years distant. January 18, 2013  Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet's moons in 1877. Over 9 kilometers across, Stickney is nearly half the diameter of Phobos itself, so large that the impact that blasted out the crater likely came close to shattering the tiny moon. This stunning, enhanced-color image of Stickney and surroundings was recorded by the HiRISE camera onboard the Mars Reconnaissance Orbiter as it passed within some six thousand kilometers of Phobos in March of 2008. Even though the surface gravity of asteroid-like Phobos is less than 1/1000th Earth's gravity, streaks suggest loose material slid down inside the crater walls over time. Light bluish regions near the crater's rim could indicate a relatively freshly exposed surface. The origin of the curious grooves along the surface is mysterious but may be related to the crater-forming impact. January 17, 2013  The aftermath of a cosmic cataclysm, supernova remnant Cassiopeia A (Cas A) is a comfortable 11,000 light-years away. Light from the Cas A supernova, the death explosion of a massive star, first reached Earth just 330 years ago. Still expanding, the explosion's debris cloud spans about 15 light-years near the center of this composite image. The scene combines color data of the starry field and fainter filaments of material at optical energies with image data from the orbiting NuSTAR X-ray telescope. Mapped to false colors, the X-ray data in blue hues trace the fragmented outer ring of the expanding shock wave, glowing at energies up to 10,000 times the energy of the optical photons. January 16, 2013  A gorgeous spiral galaxy some 100 million light-years distant, NGC 1309 lies on the banks of the constellation of the River (Eridanus). NGC 1309 spans about 30,000 light-years, making it about one third the size of our larger Milky Way galaxy. Bluish clusters of young stars and dust lanes are seen to trace out NGC 1309's spiral arms as they wind around an older yellowish star population at its core. Not just another pretty face-on spiral galaxy, observations of NGC 1309's recent supernova and Cepheid variable stars contribute to the calibration of the expansion of the Universe. Still, after you get over this beautiful galaxy's grand design, check out the array of more distant background galaxies also recorded in the above, sharp, reprocessed, Hubble Space Telescope view. January 15, 2013 Sometimes, the Sun itself seems to dance. On just this past New Year's Eve, for example, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressive prominence erupting from the Sun's surface. The dramatic explosion was captured in ultraviolet light in the above time lapse video covering four hours. Of particular interest is the tangled magnetic field that directs a type of solar ballet for the hot plasma as it falls back to the Sun. The scale of the disintegrating prominence is huge - the entire Earth would easily fit under the flowing curtain of hot gas. A quiescent prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System. The energy mechanism that creates a solar prominence is still a topic of research. As the Sun nears Solar Maximum this year, solar activity like eruptive prominences should be common. January 14, 2013  In this celestial still life composed with a cosmic brush, dusty nebula NGC 2170 shines left of image center. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae, a red emission region, many dark absorption nebulae, and a backdrop of colorful stars. Like the common household items still life painters often choose for their subjects, these clouds of gas, dust, and hot stars are also commonly found in this setting - a massive, star-forming molecular cloud in the constellation Monoceros. The giant molecular cloud, Mon R2, is impressively close, estimated to be only 2,400 light-years or so away. At that distance, this canvas would be over 40 light-years across. January 13, 2013  Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies 5 million year young star cluster NGC 602. Surrounded by natal gas and dust, NGC 602 is featured in this stunning Hubble image of the region. Fantastic ridges and swept back shapes strongly suggest that energetic radiation and shock waves from NGC 602's massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster's center. At the estimated distance of the Small Magellanic Cloud, the picture spans about 200 light-years, but a tantalizing assortment of background galaxies are also visible in the sharp Hubble view. The background galaxies are hundreds of millions of light-years or more beyond NGC 602. January 12, 2013  How common are Earth-sized planets? Quite common, according to extrapolations from new data taken by NASA's orbiting Kepler spacecraft. Current computer models are indicating that at least one in ten stars are orbited by an Earth-sized planet, making our Milky Way Galaxy the home to over ten billion Earths. Unfortunately, this estimate applies only to planets effectively inside the orbit of Mercury, making these hot-Earths poor vacation opportunities for humans. This histogram depicts the estimated fraction of stars that have close orbiting planets of various sizes. The number of Sun-like stars with Earth-like planets in Earth-like orbits is surely much less, but even so, Kepler has also just announced the discovery of four more of those. January 11, 2013  How do clusters of galaxies form and evolve? To help find out, astronomers continue to study the second closest cluster of galaxies to Earth: the Fornax cluster, named for the southern constellation toward which most of its galaxies can be found. Although almost 20 times more distant than our neighboring Andromeda galaxy, Fornax is only about 10 percent further that the better known and more populated Virgo cluster of galaxies. Fornax has a well-defined central region that contains many galaxies, but is still evolving. It has other galaxy groupings that appear distinct and have yet to merge. Seen here, almost every yellowish splotch on the image is an elliptical galaxy in the Fornax cluster. The picturesque barred spiral galaxy NGC 1365 visible on the lower right is also a prominent Fornax cluster member. January 10, 2013  Normally faint and elusive, the Jellyfish Nebula is caught in this alluring telescopic view. Drifting near bright star Eta Geminorum, at the foot of a celestial twin, the Jellyfish Nebula is seen dangling tentacles from the bright arcing ridge of emission left of center. In fact, the cosmic jellyfish is part of bubble-shaped supernova remnant IC 443, the expanding debris cloud from a massive star that exploded. Light from the explosion first reached planet Earth over 30,000 years ago. Like its cousin in astrophysical waters the Crab Nebula supernova remnant, IC 443 is known to harbor a neutron star, the remnant of the collapsed stellar core. The Jellyfish Nebula is about 5,000 light-years away. At that distance, this image would be about 100 light-years across. January 8, 2013  How was the unusual Red Rectangle nebula created? At the nebula's center is an aging binary star system that surely powers the nebula but does not, as yet, explain its colors. The unusual shape of the Red Rectangle is likely due to a thick dust torus which pinches the otherwise spherical outflow into tip-touching cone shapes. Because we view the torus edge-on, the boundary edges of the cone shapes seem to form an X. The distinct rungs suggest the outflow occurs in fits and starts. The unusual colors of the nebula are less well understood, however, and current speculation holds that they are partly provided by hydrocarbon molecules that may actually be building blocks for organic life. The Red Rectangle nebula lies about 2,300 light years away towards the constellation of the Unicorn (Monoceros). The nebula is shown above in unprecedented detail as captured recently by the Hubble Space Telescope. In a few million years, as one of the central stars becomes further depleted of nuclear fuel, the Red Rectangle nebula will likely bloom into a planetary nebula. A diagram that may help show how the current nebulae can look like this is below:  January 7, 2013  AE Aurigae is called the flaming star. The surrounding nebula IC 405 is named the Flaming Star Nebula and the region seems to harbor smoke, but there is no fire. Fire, typically defined as the rapid molecular acquisition of oxygen, happens only when sufficient oxygen is present and is not important in such high-energy, low-oxygen environments. The material that appears as smoke is mostly interstellar hydrogen, but does contain smoke-like dark filaments of carbon-rich dust grains. The bright star AE Aurigae, visible near the nebula center, is so hot it is blue, emitting light so energetic it knocks electrons away from atoms in the surrounding gas. When an atom recaptures an electron, light is emitted creating the surrounding emission nebula. In this cosmic portrait, the Flaming Star nebula lies about 1,500 light years distant, spans about 5 light years, and is visible with a small telescope toward the constellation of the Charioteer (Auriga). January 6, 2013  In silhouette against a crowded star field toward the constellation Scorpius, this dusty cosmic cloud evokes for some the image of an ominous dark tower. In fact, clumps of dust and molecular gas collapsing to form stars may well lurk within the dark nebula, a structure that spans almost 40 light-years across this gorgeous telescopic portrait. Known as a cometary globule, the swept-back cloud, extending from the lower right to the head (top of the tower) left and above center, is shaped by intense ultraviolet radiation from the OB association of very hot stars in NGC 6231, off the upper edge of the scene. That energetic ultraviolet light also powers the globule's bordering reddish glow of hydrogen gas. Hot stars embedded in the dust can be seen as bluish reflection nebulae. This dark tower, NGC 6231, and associated nebulae are about 5,000 light-years away. January 5, 2013  Get out your red/blue glasses and float next to Helene, small, icy moon of Saturn. Appropriately named, Helene is one of four known Trojan moons, so called because it orbits at a Lagrange point. A Lagrange point is a gravitationally stable position near two massive bodies, in this case Saturn and larger moon Dione. In fact, irregularly shaped ( about 36 by 32 by 30 kilometers) Helene orbits at Dione's leading Lagrange point while brotherly ice moon Polydeuces follows at Dione's trailing Lagrange point. The sharp stereo anaglyph was constructed from two Cassini images (N00172886, N00172892) captured during a close flyby in 2011. It shows part of the Saturn-facing hemisphere of Helene mottled with craters and gully-like features. January 4, 2013  Tycho crater's central peak complex casts a long, dark shadow near local sunrise in this spectacular lunarscape. The dramatic oblique view was recorded on June 10, 2011 by the Lunar Reconnaissance Orbiter. Shown in amazing detail, boulder strewn slopes and jagged shadows appear in the highest resolution version at 1.5 meters per pixel. The rugged complex is about 15 kilometers wide, formed in uplift by the giant impact that created the well-known ray crater 100 million years ago. The summit of its central peak reaches 2 kilometers above the Tycho crater floor. The highest resolution image can be found by clicking this link. January 3, 2013  Open clusters of stars can be near or far, young or old, and diffuse or compact. Found near the plane of our Milky Way galaxy, they contain from 100 to 10,000 stars, all of which formed at nearly the same time. Bright blue stars frequently distinguish younger open clusters. M35, on the upper left, is relatively nearby at 2800 light years distant, relatively young at 150 million years old, and relatively diffuse, with about 2500 stars spread out over a volume 30 light years across. An older and more compact open cluster, NGC 2158, is at the lower right. NGC 2158 is four times more distant than M35, over 10 times older, and much more compact with many more stars in roughly the same volume of space. NGC 2158's bright blue stars have self-destructed, leaving cluster light to be dominated by older and yellower stars. Both clusters are seen toward the constellation of Gemini. January 2, 2012  Most galaxies have a single nucleus - does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image. The central cloverleaf is rather light emitted from a background quasar. The gravitational field of the visible foreground galaxy breaks light from this distant quasar into four distinct images. The quasar must be properly aligned behind the center of a massive galaxy for a mirage like this to be evident. The general effect is known as gravitational lensing, and this specific case is known as the Einstein Cross. Stranger still, the images of the Einstein Cross vary in relative brightness, enhanced occasionally by the additional gravitational microlensing effect of specific stars in the foreground galaxy. January 1, 2012  Few star clusters are seen to be so close to each other. Some 7,000 light-years away, though, this pair of open or galactic star clusters is an easy binocular target, a lovely starfield in the northern constellation Perseus. Also visible to the unaided eye from dark sky areas, it was cataloged in 130 BC by Greek astronomer Hipparchus. Now known as h and chi Persei, or NGC 869 (above right) and NGC 884, the clusters themselves are separated by only a few hundred light-years and contain stars much younger and hotter than the Sun. In addition to being physically close together, the clusters' ages based on their individual stars are similar - evidence that both clusters were likely a product of the same star-forming region. December 31, 2012  What do Saturn's rings look like from the dark side? From Earth, we usually see Saturn's rings from the same side of the ring plane that the Sun illuminates them - one might call this the bright side. Geometrically, in the above picture taken in August by the robot Cassini spacecraft now orbiting Saturn, the Sun is behind the camera but on the other side of the ring plane. Such a vantage point gives a breathtaking views of the most splendid ring system in the Solar System. Strangely, the rings have similarities to a photographic negative of a front view. For example, the dark band in the middle is actually the normally bright B-ring. The ring brightness as recorded from different angles indicates ring thickness and particle density of ring particles. At the top left of the frame is Saturn's moon Tethys, which although harder to find, contains much more mass than the entire ring system. December 30, 2012   Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - makes it an excellent candidate for a full blown supernova. Historical records do show that about 150 years ago Eta Carinae underwent an unusual outburst that made it one of the brightest stars in the southern sky. Eta Carinae, in the Keyhole Nebula, is the only star currently thought to emit natural LASER light. This image, taken in 1996, brought out new details in the unusual nebula that surrounds this rogue star. Now clearly visible are two distinct lobes, a hot central region, and strange radial streaks. The lobes are filled with lanes of gas and dust which absorb the blue and ultraviolet light emitted near the center. The streaks remain unexplained. The bottom image is an artist's impression by J. Gitlin (STScI), NASA. In this model, Eta Carinae emits many LASER beams from its surrounding cloud of energized gas. Infrared LASERS and microwave MASERS are extremely rare astrophysical phenomena, but this natural ultraviolet LASER is the first of its kind to be discovered. December 29, 2012  Like a ship plowing through cosmic seas, runaway star Zeta Ophiuchi produces the arcing interstellar bow wave or bow shock seen in this stunning infrared portrait. In the false-color view, bluish Zeta Oph, a star about 20 times more massive than the Sun, lies near the center of the frame, moving toward the left at 24 kilometers per second. Its strong stellar wind precedes it, compressing and heating the dusty interstellar material and shaping the curved shock front. Around it are clouds of relatively undisturbed material. What set this star in motion? Zeta Oph was likely once a member of a binary star system, its companion star was more massive and hence shorter lived. When the companion exploded as a supernova catastrophically losing mass, Zeta Oph was flung out of the system. About 460 light-years away, Zeta Oph is 65,000 times more luminous than the Sun and would be one of the brighter stars in the sky if it weren't surrounded by obscuring dust. The image spans about 1.5 degrees or 12 light-years at the estimated distance of Zeta Ophiuchi. December 28, 2012  Fantastic shapes lurk in clouds of glowing hydrogen gas in NGC 6188, about 4,000 light-years away. The emission nebula is found near the edge of a large molecular cloud unseen at visible wavelengths, in the southern constellation Ara. Massive, young stars of the embedded Ara OB1 association were formed in that region only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions, from previous generations of massive stars, that swept up and compressed the molecular gas. Joining NGC 6188 on this cosmic canvas is rare emission nebula NGC 6164, also created by one of the region's massive O-type stars. Similar in appearance to many planetary nebulae, NGC 6164's striking, symmetric gaseous shroud and faint halo surround its bright central star at the lower right. The field of view spans about two full Moons, corresponding to 70 light years at the estimated distance of NGC 6188. December 27, 2012  What's in this smooth soil on Mars? In late October, NASA's robotic Curiosity rover stopped near a place dubbed Rocknest as it continues to explore Gale Crater on Mars. Rocknest is the group of stones seen near the top left of the above image - just to the left of Curiosity's mast. Of particular interest was the unusually smooth patch of soil named Wind Drift seen to the left of Curiosity, which was likely created by the Martian wind blowing fine particles into Rocknest's wake. The above image shows part of Mt. Sharp in the background to upper right, and, oddly, almost the entire rover itself, digitally reconstructed from 55 frames while digitally removing an extended arm. Curiosity scooped several sand samples from Wind Drift into its Chemistry and Mineralogy Experiment (CheMin) and the Sample Analysis at Mars (SAM) laboratory for a detailed analysis. Preliminary data from the soil indicates a small amount of one-carbon organic material the origin of which it presently unknown. Although the organic signal might be just contaminants from Earth, the exciting possibility that it could be from Mars itself will remain a focus of future exploration and research. December 26, 2012  Makemake is one of the largest objects known in the outer Solar System. Pronounced MAH-kay MAH-kay, this Kuiper belt object is about two-thirds the size of Pluto, orbits the Sun only slightly further out than Pluto, and appears only slightly dimmer than Pluto. Makemake, however, has an orbit much more tilted to the ecliptic plane of the planets than Pluto. Discovered by a team led by Mike Brown (Caltech) in 2005, the outer Solar System orb was officially named Makemake for the creator of humanity in the Rapa Nui mythology of Easter Island. In 2008, Makemake was classified as a dwarf planet under the subcategory plutoid, making Makemake the third cataloged plutoid after Pluto and Eris. Makemake is known to be a world somewhat red in appearance, with colors indicating it is likely covered with patchy areas of frozen methane. No images of Makemake's surface yet exist, but an artist's illustration of the distant world is shown above. Careful monitoring of the brightness drop of a distant star recently eclipsed by Makemake indicates that the dwarf planet has little atmosphere. December 25, 2012  Merry Christmas! In this evocative night skyscape a starry band of the Milky Way climbs over Yosemite Valley, Sierra Nevada Range, planet Earth. Jupiter is the brightest celestial beacon on the wintry scene, though. Standing nearly opposite the Sun in the constellation Taurus, the wandering planet joins yellowish Aldebaran and the Hyades star cluster. Below, Orion always comes up sideways over a fence of mountains. And from there the twin stars of Gemini rise just across the Milky Way. As this peaceful winter night began, they followed Auriga the charioteer, its alpha star Capella near the top of the frame. December 24, 2012   Recognized since antiquity and depicted on the shield of Achilles according to Homer, stars of the Hyades cluster form the head of the constellation Taurus the Bull. Their general V-shape is anchored by Aldebaran, the eye of the Bull and by far the constellation's brightest star. Yellowish in appearance, red giant Aldebaran is not a Hyades cluster member, though. Modern astronomy puts the Hyades cluster 151 light-years away making it the nearest established open star cluster, while Aldebaran lies at less than half that distance, along the same line-of-sight. Along with colorful Hyades stars, this stellar holiday portrait locates Aldebaran just below center, as well as another open star cluster in Taurus, NGC 1647 at the left, some 2,000 light-years or more in the background. The central Hyades stars are spread out over about 15 light-years. Formed some 800 million years ago, the Hyades star cluster may share a common origin with M44 (Praesepe), a naked-eye open star cluster in Cancer, based on M44's motion through space and remarkably similar age. December 23, 2012  Comet Hale-Bopp, the Great Comet of 1997, became much brighter than any surrounding stars. It was seen even over bright city lights. Away from city lights, however, it put on quite a spectacular show. Here Comet Hale-Bopp was photographed above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo, Italy. Comet Hale-Bopp's blue ion tail, consisting of ions from the comet's nucleus, is pushed out by the solar wind. The white dust tail is composed of larger particles of dust from the nucleus driven by the pressure of sunlight, that orbit behind the comet. Observations showed that Comet Hale-Bopp's nucleus spins about once every 12 hours. A comet that may well exceed Hale-Bopp's peak brightness is expected to fall into the inner Solar System next year. December 22, 2012  Splendors seldom seen are revealed in this glorious picture from Saturn's shadow. Imaged by Cassini on October 17, 2012 during its 174th orbit, the ringed planet's night side is viewed from a perspective 19 degrees below the ring plane at a distance of about 800,000 kilometers with the Sun almost directly behind the planet. A 60 frame mosaic, images made with infrared, red, and violet filters were combined to create an enhanced, false-color view. Strongly backlit, the rings look bright away from the planet but dark in silhouette against the gas giant. Above center, they reflect a faint, eerie light on the cloud tops while Saturn casts its own dark shadow on the rings. A similar Cassini image from 2006 also featured planet Earth as a pale blue dot in the distance. Instead, this scene includes icy moons Enceladus (closer to the rings) and Tethys below the rings on the left. December 21, 2012  Welcome to the December solstice, a day the world does not end... even according to the Mayan Calendar. To celebrate, consider this dramatic picture of Orion rising over El Castillo, the central pyramid at Chichén Itzá, one of the great Mayan centers on the Yucatán peninsula. Also known as the Temple of Kukulkan it stands 30 meters tall and 55 meters wide at the base. Built up as a series of square terraces by the pre-Columbian civilization between the 9th and 12th century, the structure can be used as a calendar and is noted for astronomical alignments. In fact, the Mayans were accomplished astronomers and mathematicians, accurately using the cyclic motions of the stars, Sun, Moon, and planets to measure time and construct calendars. Peering through clouds in this night skyscape, stars in the modern constellation Orion the Hunter represented a turtle in the Mayan sky. Tak sáamal. December 20, 2012  The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy and astronomers in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this sharp composite image, a 25 panel mosaic, nicely shows off M33's blue star clusters and pinkish star forming regions that trace the galaxy's loosely wound spiral arms. In fact, the cavernous NGC 604 is the brightest star forming region, seen here at about the 1 o'clock position from the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick for establishing the distance scale of the Universe. December 19, 2012  Why is this nebula so complex? When a star like our Sun is dying, it will cast off its outer layers, usually into a simple overall shape. Sometimes this shape is a sphere, sometimes a double lobe, and sometimes a ring or a helix. In the case of planetary nebula NGC 5189, however, no such simple structure has emerged. To help find out why, the Earth-orbiting Hubble Space Telescope recently observed NGC 5189 in great detail. Previous findings indicated the existence of multiple epochs of material outflow, including a recent one that created a bright but distorted torus running horizontally across image center. Results appear consistent with a hypothesis that the dying star is part of a binary star system with a precessing symmetry axis. Given this new data, though, research is sure to continue. NGC 5189 spans about three light years and lies about 3,000 light years away toward the southern constellation of the Fly (Musca). December 18, 2012  Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, six-sided shaped crystals as it falls from high-level clouds. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture taken last week, a sun-pillar reflects light from a Sun setting over Östersund, Sweden. December 17, 2012  Why does this galaxy have so many big black holes? No one is sure. What is sure is that NGC 922 is a ring galaxy created by the collision of a large and small galaxy about 300 million years ago. Like a rock thrown into a pond, the ancient collision sent ripples of high density gas out from the impact point near the center that partly condensed into stars. Pictured above is NGC 922 with its beautifully complex ring along the left side, as imaged recently by the Hubble Space Telescope. Observations of NGC 922 with the Chandra X-ray Observatory, however, show several glowing X-ray knots that are likely large black holes. The high number of massive black holes was somewhat surprising as the gas composition in NGC 922 - rich in heavy elements - should have discouraged almost anything so massive from forming. Research is sure to continue. NGC 922 spans about 75,000 light years, lies about 150 million light years away, and can be seen with a small telescope toward the constellation of the furnace (Fornax). December 16, 2012  Is this coat hanger a star cluster or an asterism? This cosmic hang-up has been debated over much of last century, as astronomers wondered whether this binocular-visible object is really a physically associated open cluster or a chance projection. Chance star projections are known as asterisms, an example of which is the popular Big Dipper. Recent precise measurements from different vantage points in the Earth's orbit around the Sun have uncovered discrepant angular shifts indicating that the Coat Hanger is better described as an asterism. Known more formally as Collinder 399, this bright stellar grouping is wider than the full moon and lies in the constellation of the Fox (Vulpecula). On the far right of the image is the open cluster of stars NGC 6802. Individually the stars range between magnitudes 5 and 7, but combined the coat hanger is magnitude 3.6. The coat hanger can be found just south of Cygnus. December 15, 2012  From a radiant point in the constellation of the Twins, the annual Geminid meteor shower rained down on planet Earth this week. Recorded near the shower's peak in the early hours of December 14, this skyscape captures Gemini's lovely shooting stars in a careful composite of 30 exposures, each 20 seconds long, from the dark of the Chilean Atacama Desert over ESO's Paranal Observatory. In the foreground Paranal's four Very Large Telescopes, four Auxillary Telescopes, and the VLT Survey telescope are all open and observing. The skies above are shared with bright Jupiter (left), Orion, (top left), and the faint light of the Milky Way. Dust swept up from the orbit of active asteroid 3200 Phaethon, Gemini's meteors enter the atmosphere traveling at about 22 kilometers per second. December 14, 2012  On the morning of November 14, sky gazers from around the world gathered on this little planet to stand in the dark umbral shadow of the Moon. Of course, the Moon cast the shadow during last month's total solar eclipse, and the little planet is actually a beach on Green Island off the coast of Queensland, Australia. The picture itself, the first little planet projection of a total solar eclipse, is a digitally warped and stitched wrap-around of 8 images covering 360x180 degrees. To make it, the intrepid photographer had to remember to shoot both toward and away(!) from the eclipse during the excitement of totality. Near this little planet's horizon, the eclipsed Sun is just above center, surrounded by the glowing solar corona. Venus can be spotted toward the top of the frame. At bottom right, bright star Sirius shines at the tip of an alarmingly tall tree. December 13, 2012  Get out your red/blue glasses and check out this awesome stereo view of another world. The scene was recorded by Apollo 17 mission commander Eugene Cernan on December 11, 1972, one orbit before descending to land on the Moon. The stereo anaglyph was assembled from two photographs (AS17-147-22465, AS17-147-22466) captured from his vantage point on board the Lunar Module Challenger as he and Dr. Harrison Schmitt flew over Apollo 17's landing site in the Taurus-Littrow Valley. The broad, sunlit face of the mountain dubbed South Massif, rises near the center of the frame, above the dark floor of Taurus-Littrow to its left. Beyond the mountains, toward the lunar limb, lies the Moon's Mare Serenitatis. Piloted by Ron Evans, the Command Module America is visible in orbit in the foreground against the South Massif's peak. To see all of Apollo 17's photos, you can go here. December 12, 2012  In front of a famous background of stars and galaxies lies some of Earth's more unusual trees. Known as quiver trees, they are actually succulent aloe plants that can grow to tree-like proportions. The quiver tree name is derived from the historical usefulness of their hollowed branches as dart holders. Occurring primarily in southern Africa, the trees pictured in the above 16-exposure composite are in Quiver Tree Forest located in southern Namibia. Some of the tallest quiver trees in the park are estimated to be about 300 years old. Behind the trees is light from the small town of Keetmanshoop, Namibia. Far in the distance, arching across the background, is the majestic central band of our Milky Way Galaxy. Even further in the distance, visible on the image left, are the Large and Small Magellanic Clouds, smaller satellite galaxies of the Milky Way that are prominent in the skies of Earth's southern hemisphere. December 11, 2012  Stars are sometimes born in the midst of chaos. About 3 million years ago in the nearby galaxy M33, a large cloud of gas spawned dense internal knots which gravitationally collapsed to form stars. NGC 604 was so large, however, it could form enough stars to make a globular cluster. Many young stars from this cloud are visible in the above image from the Hubble Space Telescope, along with what is left of the initial gas cloud. Some stars were so massive they have already evolved and exploded in a supernova. The brightest stars that are left emit light so energetic that they create one of the largest cloud of ionized hydrogen gas known, comparable to the Tarantula Nebula in our Milky Way's close neighbor, the Large Magellanic Cloud. December 10, 2012 Source: Have you ever experienced a total eclipse of the Sun? The above time-lapse movie depicts such an eclipse in dramatic detail as visible from Australia last month. As the video begins, a slight dimming of the Sun and the surrounding Earth is barely perceptible. Suddenly, as the Moon moves to cover nearly the entire Sun, darkness sweeps in from the left - the fully blocked part of the Sun. At totality, only the bright solar corona extends past the edges of the Moon, and darkness surrounds you. Distant horizons are still bright, though, as they are not in the darkest part of the shadow. At mid-totality the darkness dips to the horizon below the eclipsed Sun, created by the shadow cone - a corridor of shadow that traces back to the Moon. As the total solar eclipse ends - usually after a few minutes - the process reverses and Moon's shadow moves off to the other side. Solar eclipses can frequently be experienced at gatherings organized along the narrow eclipse path as well as specialized cruises and plane flights. December 9, 2012  In 1984, high above the Earth's surface, an astronaut captured a satellite. It was the second satellite captured that mission. Pictured above, astronaut Dale A. Gardner flies free using the Manned Maneuvering Unit and begins to attach a control device dubbed the Stinger to the rotating Westar 6 satellite. Communications satellite Westar 6 had suffered a rocket malfunction that left it unable to reach its intended high geosynchronous orbit. Both the previously caught Palapa B-2 satellite and the Westar 6 satellite were guided into the cargo bay of the Space Shuttle Discovery and returned to Earth. Westar 6 was subsequently refurbished and sold. December 8, 2012  This remarkably complete view of Earth at night is a composite of cloud-free, nighttime images. The images were collected during April and October 2012 by the Suomi-NPP satellite from polar orbit about 824 kilometers (512 miles) above the surface using its Visible Infrared Imaging Radiometer Suite (VIIRS). VIIRS offers greatly improved resolution and sensitivity compared to past global nightlight detecting instrumentation on DMSP satellites. It also has advantages compared to cameras on the International Space Station. While the space station passes over the same point on Earth every two or three days, Suomi-NPP passes over the same point twice a day at about 1:30am and 1:30pm local time. Easy to recognize here, city lights identify major population centers, tracking the effects of human activity and influence across the globe. That makes nighttime images of our fair planet among the most interesting and important views from space. December 7, 2012   In a continuation from yesterday's picture of the day, we continue with the same globular cluster. Visible light images show the central region of globular cluster 47 Tucanae is closely packed, with stars less than a tenth of a light-year apart. This Chandra false-color x-ray view of central 47 Tuc also shows the cluster is a popular neighborhood for x-ray stars, many of which are "normal" stars co-orbiting with extremely dense neutron stars - stars with the mass of the Sun but the diameter of Manhattan Island. One of the most remarkable of these exotic binary systems is cataloged as 47 Tuc W, a bright source near the center of this image. The system consists of a low mass star and a a neutron star that spins once every 2.35 milliseconds. Such neutron stars are known to radio astronomers as millisecond pulsars, believed to be driven to such rapid rotation by material falling from the normal star onto its dense companion. In fact, x-ray observations of the 47 Tuc W system link this spin-up mechanism observed to operate in other x-ray binary stars with fast rotating millisecond pulsars. Pulsars have their own distinct sound, and it is possible to listen to what a pulsar sounds like via radio waves by clicking the gray triangle on this page which gives you various pulsar recordings. December 6, 2012  Globular star cluster 47 Tucanae is a jewel of the southern sky. Also known as NGC 104, it roams the halo of our Milky Way Galaxy along with around 200 other globular star clusters. The second brightest globular cluster (after Omega Centauri) as seen from planet Earth, it lies about 13,000 light-years away and can be spotted naked-eye near the Small Magellanic Cloud (SMC) in the constellation of the Toucan. Of course, the SMC is some 210,000 light-years distant, a satellite galaxy of our Milky Way and not physically close to 47 Tuc. Stars on the outskirts of the SMC are seen at the upper left of this broad southern skyscape. Toward the lower right with about the same apparent diameter as a Full Moon, dense cluster 47 Tuc is made up of several million stars in a volume only about 120 light-years across. Away from the bright cluster core, the red giants of 47 Tuc are easy to pick out as yellowish tinted stars. Globular cluster 47 Tuc is also home to exotic x-ray binary star systems. December 5, 2012  Why does this galaxy emit such spectacular jets? No one is sure, but it is likely related to an active supermassive black hole at its center. The galaxy at the image center, Hercules A, appears to be a relatively normal elliptical galaxy in visible light. When imaged in radio waves, however, tremendous plasma jets over one million light years long appear. Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black hole at our Milky Way's center. Pictured above is a visible light image obtained by the Earth-orbiting Hubble Space Telescope superposed with a radio image taken by the recently upgraded Very Large Array (VLA) of radio telescopes in New Mexico, USA. The physics that creates the jets remains a topic of research with a likely energy source being infalling matter swirling toward the central black hole. December 4, 2012  What's happening at the north pole of Saturn? A vortex of strange and complex swirling clouds. The center of this vortex was imaged in unprecedented detail last week by the robotic Cassini spacecraft orbiting Saturn. These clouds lie at the center of the unusual hexagonal cloud system that surrounds the north pole of Saturn. Saturn's north pole precessed into sunlight just a few years ago, with Cassini taking only infrared images of the shadowed region previously. The above image is raw and unprocessed and is being prepared for release in 2013. Several similar images of the region have recently been condensed into a movie. Planetary scientists are sure to continue to study this most unusual cloud formation for quite some time. December 3, 2012   Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon. This past Saturday night was just such a time near Madrid, Spain, where a winter sky displayed not only a bright Moon but as many as four rare lunar halos. The brightest object, near the top of the above image, is the Moon. Light from the Moon refracts through tumbling hexagonal ice crystals into a 22 degree halo seen surrounding the Moon. Elongating the 22 degree arc horizontally is a circumscribed halo caused by column ice crystals. More rare, some moonlight refracts through more distant tumbling ice crystals to form a (third) rainbow-like arc 46 degrees from the Moon and appearing here just above a picturesque winter landscape. Furthermore, part of a whole 46 degree circular halo is also visible, so that an extremely rare - especially for the Moon - quadruple halo was actually imaged. The snow-capped trees in the foreground line the road Puerto de Navacerrada in the Sierra de Guadarrama mountain range near Madrid. Far in the background is a famous winter skyscape that includes Sirius, the belt of Orion, and Betelgeuse all visible between the inner and outer arcs. Halos and arcs typically last for minutes to hours, so if you do see one there should be time to invite family, friends or neighbors to share your unusual lensed vista of the sky. December 2, 2012  Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for "counter glow") can be seen 180 degrees around from the Sun in an extremely dark sky. The gegenschein is sunlight back-scattered off small interplanetary dust particles. These dust particles are millimeter sized splinters from asteroids and orbit in the ecliptic plane of the planets. Pictured above from 2008 October is one of the more spectacular pictures of the gegenschein yet taken. Here a deep exposure of an extremely dark sky over Paranal Observatory in Chile shows the gegenschein so clearly that even a surrounding glow is visible. In the foreground are several of the European Southern Observatory's Very Large Telescopes, while notable background objects include the Andromeda galaxy toward the lower left and the Pleiades star cluster just above the horizon. The gegenschein is distinguished from zodiacal light near the Sun by the high angle of reflection. During the day, a phenomenon similar to the gegenschein called the glory can be seen in reflecting air or clouds opposite the Sun from an airplane. The glory is shown below:  December 1, 2012  Innermost planet Mercury would probably not be a good location for an interplanetary winter olympics. But new results based on data from the Mercury orbiting MESSENGER spacecraft indicate that it does have substantial water ice in permanently shadowed regions within craters near its north pole. The possibility of ice on Mercury has been entertained for years, inspired by the discovery of radar bright, hence highly reflective, regions near the north pole. Highlighted in yellow in this map based on projected MESSENGER images, radar bright regions are seen to correspond with floors and walls of north polar impact craters. Farther from the pole the regions are concentrated on the north facing crater walls. MESSENGER's neutron spectroscopy and thermal models for the craters indicate material in these regions has a hydrogen content consistent with nearly pure water ice and is trapped in an area with temperatures that remain below 100 kelvins (-280 deg.F, -173 deg.C). In circumstances similar to permanent shadows in craters of the Moon, debris from comet impacts is thought to be the source of ice on Mercury. November 30, 2012  Cosmic clouds of gas and dust drift across this magnificent mosaic covering a 12x12 degree field within the high flying constellation Cygnus. The collaborative skyscape, a combination of broad and narrow band image data presented in the Hubble palette, is anchored by bright, hot, supergiant star Deneb, below center near the left edge. Alpha star of Cygnus, Deneb, is the top of the Northern Cross asterism and is seen here next to the dark void known as the Northern Coal Sack. Below Deneb are the recognizable North America and Pelican nebulae (NGC 7000 and IC 5070). Another supergiant star, Sadr (Gamma Cygni) is near the center of the field just above the bright wings of the Butterfly Nebula. A line continuing up and right will encounter the more compact Crescent Nebula and finally the Tulip Nebula near the top of the frame. Most of these complex nebulosities are located about 2,000 light-years away. Along with the Sun, they lie in the Orion spiral arm of our Milky Way galaxy. November 29, 2012  Did you see the big, bright, beautiful Full Moon Wednesday night? That was actually a Micro Moon! On that night, the smallest Full Moon of 2012 reached its full phase only about 4 hours before apogee, the most distant point from Earth in the Moon's elliptical orbit. Of course, earlier this year on May 6, a Full Super Moon was near perigee, the closest point in its orbit. The relative apparent size of November 28's Micro Moon (right) is compared to the famous May 6 Super Moon in these two panels, matching telescopic images from Bucharest, Romania. The difference in apparent size represents a difference in distance of just under 50,000 kilometers between apogee and perigee, given the Moon's average distance of about 385,000 kilometers. How long do you have to wait to see another Full Micro Moon? Until January 16, 2014, when the lunar full phase will occur within about 3 hours of apogee. November 28, 2012  On December 3 (UT), Jupiter, the solar system's largest planet, will be at opposition, opposite the Sun in planet Earth's sky, shining brightly and rising as the Sun sets. That configuration results in Jupiter's almost annual closest approach to planet Earth. So, near opposition the gas giant offers earthbound telescopes stunning views of its stormy, banded atmosphere and large Galilean moons. For example, this sharp series was recorded on the night of November 16/17 from the island of Sardinia near Dolianova, Italy. North is up in the images that show off Jupiter's famous Great Red Spot, and planet girdling dark belts and light zones. Also seen in transit is Jupiter's volcanic moon Io, its round, dark shadow tracking across the Jovian cloud tops as the sequence progresses left to right. November 27, 2012   Wisps like this are all that remain visible of a Milky Way star. About 9,000 years ago that star exploded in a supernova leaving the Veil Nebula, also known as the Cygnus Loop. At the time, the expanding cloud was likely as bright as a crescent Moon, remaining visible for weeks to people living at the dawn of recorded history. Today, the resulting supernova remnant has faded and is now visible only through a small telescope directed toward the constellation of the Swan (Cygnus). The remaining Veil Nebula is physically huge, however, and even though it lies about 1,400 light-years distant, it covers over five times the size of the full Moon. In images like this of the complete Veil Nebula, studious readers should be able to identify several of the individual filaments. A bright wisp at the right is known as the Witch's Broom Nebula. November 26, 2012  Wisps like this are all that remain visible of a Milky Way star. About 9,000 years ago that star exploded in a supernova leaving the Veil Nebula, also known as the Cygnus Loop. At the time, the expanding cloud was likely as bright as a crescent Moon, remaining visible for weeks to people living at the dawn of recorded history. Today, the resulting supernova remnant has faded and is now visible only through a small telescope directed toward the constellation of the Swan (Cygnus). The remaining Veil Nebula is physically huge, however, and even though it lies about 1,400 light-years distant, it covers over five times the size of the full Moon. In images like this of the complete Veil Nebula, studious readers should be able to identify several of the individual filaments. A bright wisp at the right is known as the Witch's Broom Nebula. November 25, 2012  They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars. At that time, dark sand on the interior of Martian sand dunes became more and more visible as the spring Sun melted the lighter carbon dioxide ice. When occurring near the top of a dune, dark sand may cascade down the dune leaving dark surface streaks - streaks that might appear at first to be trees standing in front of the lighter regions, but cast no shadows. Objects about 25 centimeters across are resolved on this image spanning about one kilometer. Close ups of some parts of this image show billowing plumes indicating that the sand slides were occurring even when the image was being taken. November 24, 2012  Barred spiral galaxy NGC 1365 is truly a majestic island universe some 200,000 light-years across. Located a mere 60 million light-years away toward the chemical constellation Fornax, NGC 1365 is a dominant member of the well-studied Fornax galaxy cluster. This sharp color image shows intense star forming regions at the ends of the bar and along the spiral arms, and details of dust lanes cutting across the galaxy's bright core. At the core lies a supermassive black hole. Astronomers think NGC 1365's prominent bar plays a crucial role in the galaxy's evolution, drawing gas and dust into a star-forming maelstrom and ultimately feeding material into the central black hole. Discovered on October 27, the position of a bright supernova is indicated in NGC 1365. Cataloged as SN2012fr, the type Ia supernova is the explosion of a white dwarf star. November 23, 2012  East of Antares, dark markings sprawl through crowded star fields toward the center of our Milky Way Galaxy. Cataloged in the early 20th century by astronomer E. E. Barnard, the obscuring interstellar dust clouds include B59, B72, B77 and B78, seen in silhouette against the starry background. Here, their combined shape suggests a pipe stem and bowl, and so the dark nebula's popular name is the Pipe Nebula. The deep and expansive view was represents nearly 24 hours of exposure time recorded in very dark skies of the Chilean Atacama desert. It covers a full 10 by 10 degree field in the pronounceable constellation Ophiuchus. The Pipe Nebula is part of the Ophiuchus dark cloud complex located at a distance of about 450 light-years. Dense cores of gas and dust within the Pipe Nebula are collapsing to form stars. November 22, 2012  A cosmic grain of sand left the long and colorful trail across this all-sky view. Its grazing impact with planet Earth's atmosphere began at 71 kilometers per second. With the Milky Way stretching from horizon to horizon, the scene was captured on the night of November 17 from the astronomically popular high plateau at Champ du Feu in Alsace, France. Of course, the earthgrazer meteor belongs to this month's Leonid meteor shower, produced as our fair planet annually sweeps through dust from the tail of periodic Comet Tempel-Tuttle. The shower's radiant point in the constellation Leo is very close to the eastern horizon, near the start of the trail at the lower left. Bright planet Jupiter is also easy to spot, immersed in a faint band of Zodiacal light just below and right of center. The image is part of a dramatic time-lapse video that began only 7 minutes before the long leonid crossed the sky. Link to video is here: http://vimeo.com/53980967 November 21, 2012  As the total phase of last week's solar eclipse came to an end, sunlight streaming past the edge of the Moon created the fleeting appearance of a glistening diamond ring in the sky. And while most eclipse watchers did not consider clouds a welcome sight, a view through thin clouds north of Cairns in Queensland, Australia also revealed these remarkable flickering shadow bands. Projected onto the cloud layer, the bands are parallel to the sliver of emerging sunlight. Caused by turbulence in Earth's atmosphere refracting the sliver of sunlight, the narrow bands were captured in this brief, 1/1000th second exposure. November 20, 2012  Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens. Because most of the crystals have a similar elongated hexagonal shape, light entering one crystal face and exiting through the opposing face refracts 22 degrees, which corresponds to the radius of the Moon Halo. A similar Sun Halo may be visible during the day. The setting of the above picture is Athens San Sebastian, Greece. The distant planet Jupiter appears by chance on the halo's left. Exactly how ice-crystals form in clouds remains under investigation. November 19, 2012  What's happening in the sky over Monument Valley? A meteor shower. Over the past weekend the Leonid meteor shower has been peaking. The image - actually a composite of six exposures of about 30 seconds each - was taken in 2001, a year when there was a much more active Leonids shower. At that time, Earth was moving through a particularly dense swarm of sand-sized debris from Comet Tempel-Tuttle, so that meteor rates approached one visible streak per second. The meteors appear parallel because they all fall to Earth from the meteor shower radiant - a point on the sky towards the constellation of the Lion (Leo). Although the predicted peak of this year's Leonid meteor shower is over, another peak may be visible early tomorrow morning. By the way - how many meteors can you identify in the above image? November 18, 2012  How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, nearly making it the record holder. This star is the brightest object located just above the gas front in the above image. Close inspection of images taken with the Hubble Space Telescope, however, have shown that Pismis 24-1 derives its brilliant luminosity not from a single star but from three at least. Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. Toward the bottom of the image, stars are still forming in the associated emission nebula NGC 6357. Appearing perhaps like a Gothic cathedral, energetic stars near the center appear to be breaking out and illuminating a spectacular cocoon. November 17, 2012  This lovely view from northern Spain at Cape Creus on the easternmost point of the Iberian peninsula, looks out across the Mediteranean and up into the stream of the 2002 Leonid meteor shower. The picture is a composite of thirty separate one minute exposures taken through a fisheye lens. Over 70 leonid meteors are visible, some seen nearly head on. Bright Jupiter is positioned just to the right of the shower's radiant in Leo. Perched on the moonlit rocks at the bottom right, Leica, the photographers' dog, seems to be watching the on going celestial display and adds a surreal visual element to the scene. Sky watchers will have their best view under dark skies in early morning hours with Leo rising above the eastern horizon. November 16, 2012  On the morning of November 14, the Moon's umbral shadow tracked across northern Australia before heading into the southern Pacific. Captured from a hilltop some 30 miles west of the outback town of Mount Carbine, Queensland, a series of exposures follows the progress of the total solar eclipse in this dramatic composite image. The sequence begins near the horizon. The Moon steadily encroaches on the on the reddened face of the Sun, rising as the eclipse progresses. At the total phase, lasting about 2 minutes for that location, an otherwise faint solar corona shimmers around the eclipsed disk. Recorded during totality, the background exposure shows a still sunlit sky near the horizon, just beyond a sky darkened by the shadow of the Moon. November 15, 2012  This month's New Moon brought a total solar eclipse to parts of planet Earth on November 13 (UT). Most of the total eclipse track fell across the southern Pacific, but the Moon's dark umbral shadow began its journey in northern Australia on Wednesday morning, local time. But What does a solar eclipse look like from a plane? Above the clouds, it is very easy to see where the moon has covered the sun and where it has partially covered the sun. This neat solar eclipse photo was taken during a solar eclipse in 2010 and clearly demonostrates the dramatic darkening of the sky / ground as the shadow of the moon blankets the Earth. Under a total solar eclipse, the ground becomes almost night-like for a few minutes. Sunlight streaming through gaps in the rugged profile of the lunar limb creates the brilliant but fleeting Baily's Beads. November 14, 2012  This image of Saturn could not have been taken from Earth. No Earth based picture could possibly view the night side of Saturn and the corresponding shadow cast across Saturn's rings. Since Earth is much closer to the Sun than Saturn, only the day side of the planet is visible from the Earth. In fact, this image mosaic was taken in January 2007 by the robotic Cassini spacecraft now orbiting Saturn. The beautiful rings of Saturn are seen in full expanse, while cloud details are visible near the night-day terminator divide. November 13, 2012  Which feature takes your breath away first in this encompassing panorama of land and sky? The competition is strong with a waterfall, meteor, starfield, and even a moonbow all vying for attention. It is interesting to first note, though, what can't be seen -- a rising moon on the other side of the camera. The bright moon not only illuminated this beautiful landscape in Queensland, Australia last June, but also created the beautiful moonbow seen in front of Wallaman Falls. Just above the ridge in the above image is the horizontal streak of an airplane. Toward the top of the frame is the downward streak of a bright meteor, a small pebble from across our Solar System that lit up as it entered the Earth's atmosphere. Well behind the meteor are numerous bright stars and nebula seen toward the center of our Galaxy. Finally, far in the background, is the band of our Milky Way Galaxy, running diagonally from the lower left to the upper right in the image but also circling the entire sky. November 12, 2012  The Kreutz Group of comets has resulted in more than ten bright comets and many hundreds of small fragments that have only been observed by dedicated solar satellites. The last Great Sungrazer was White-Ortiz-Bolelli seen in 1970. The attached shows Comet White-Ortiz-Bolelli (S&T july 1970, p16) and the new record holder, Comet Lovejoy, photographed Christmas eve from Wagga Wagga, Australia, by Dr Graeme White; the co-discover of Comet White-Ortiz-Bolelli (some 40 years earlier) and Michael Maher. Note the striking similarity of the structure – these two comets are truly sisters. The photo was taken at Christmas eve, at 04:00 local Summer time using a Nikon D90 at 18 mm, f/3.5, maximum ISO and with full noise reduction. Losmandy mount. November 11, 2012  Just before the Sun blacks out, something strange occurs. As the Moon moves to completely cover the Sun in a total solar eclipse - like the one set to occur over parts of Australia on Tuesday - beads of bright sunlight stream around the edge of the Moon. This effect, known as Baily's beads, is named after Francis Baily who called attention to the phenomenon in 1836. Although, the number and brightness of Baily's beads used to be unpredictable, today the Moon is so well mapped that general features regarding Baily's beads are expected. When a single bead dominates, it is called the diamond ring effect, and is typically seen just before totality. Pictured above, horizontally compressed, a series of images recorded Baily's beads at times surrounding the 2008 total solar eclipse visible from Novosibirsk, Russia. At the end of totality, as the Sun again emerges from behind the moon, Baily's beads may again be visible - but now on the other side of the Moon. November 10, 2012  NGC 660 is featured in this cosmic snapshot, a sharp composite of broad and narrow band filter image data from the Gemini North telescope on Mauna Kea. Over 20 million light-years away and swimming within the boundaries of the constellation Pisces, NGC 660's peculiar appearance marks it as a polar ring galaxy. A rare galaxy type, polar ring galaxies have a substantial population of stars, gas, and dust orbiting in rings nearly perpendicular to the plane of the galactic disk. The bizarre-looking configuration could have been caused by the chance capture of material from a passing galaxy by a disk galaxy, with the captured debris eventually strung out in a rotating ring. The violent gravitational interaction would account for the myriad pinkish star forming regions scattered along NGC 660's ring. The polar ring component can also be used to explore the shape of the galaxy's otherwise unseen dark matter halo by calculating the dark matter's gravitational influence on the rotation of the ring and disk. Broader than the disk, NGC 660's ring spans over 50,000 light-years. November 9, 2012  Cosmic clouds seem to form fantastic shapes in the central regions of emission nebula IC 1805. Of course, the clouds are sculpted by stellar winds and radiation from massive hot stars in the nebula's newborn star cluster, Melotte 15. About 1.5 million years young, the cluster stars are toward the right in this colorful skyscape, along with dark dust clouds in silhouette against glowing atomic gas. A composite of narrow and broad band telescopic images, the view spans about 30 light-years and includes emission from hydrogen in green, sulfur in red, and oxygen in blue hues. Wider field images reveal that IC 1805's simpler, overall outline suggests its popular name - The Heart Nebula. IC 1805 is located about 7,500 light years away toward the constellation Cassiopeia. November 8, 2012  Sometimes a morning sky can be a combination of serene and surreal. Such a sky perhaps existed before sunrise this past Sunday as viewed from a snowy slope in eastern Switzerland. Quiet clouds blanket the above scene, lit from beneath by lights from the village of Trübbach. A snow covered mountain, Mittlerspitz, poses dramatically on the upper left, hovering over the small town of Balzers, Liechtenstein far below. Peaks from the Alps can be seen across the far right, just below the freshly rising Sun. Visible on the upper right are the crescent Moon and the bright planet Venus. Venus will remain in the morning sky all month, although it will likely not be found in such a photogenic setting. November 7, 2012  In the distant universe, time appears to run slowly. Since time-dilated light appears shifted toward the red end of the spectrum (redshifted), astronomers are able to use cosmological time-slowing to help measure vast distances in the universe. Above, the light from distant galaxies has been broken up into its constituent colors (spectra), allowing astronomers to measure the redshift of known spectral lines. The novelty of the above image is that the distance to hundreds of galaxies can now be measured on a single frame using the Visible MultiObject Spectrograph operating at the Very Large Telescope array in Chile. Analyzing the space distribution of distant objects will allow insight into when and how stars, galaxies, and quasars formed, clustered, and evolved in the early universe. November 6, 2012  Why is this moon shaped like a smooth egg? The robotic Cassini spacecraft completed the first flyby ever of Saturn's small moon Methone in May and discovered that the moon has no obvious craters. Craters, usually caused by impacts, have been seen on every moon, asteroid, and comet nucleus ever imaged in detail -- until now. Even the Earth and Titan have craters. The smoothness and egg-like shape of the 3-kilometer diameter moon might be caused by Methone's surface being able to shift -- something that might occur were the moon coated by a deep pile of sub-visual rubble. If so, the most similar objects in our Solar System would include Saturn's moons Telesto, Pandora, Calypso, as well as asteroid Itokawa, all of which show sections that are unusually smooth. Methone is not entirely featureless, though, as some surface sections appears darker than others. Although flybys of Methone are difficult, interest in the nature and history of this unusual moon is sure to continue. November 5, 2012  On some nights, the sky is the best show in town. On this night, the sky was not only the best show in town, but a composite image of the sky won an international competition for landscape astrophotography. The above winning image was taken on March 2011 over Jökulsárlón, the largest glacial lake in Iceland. The photographer combined six exposures to capture not only two green auroral rings, but their reflections off the serene lake. Visible in the distant background sky is the band of our Milky Way Galaxy, the Pleiades open clusters of stars, and the Andromeda galaxy. A powerful coronal mass ejection from the Sun caused auroras to be seen as far south as Wisconsin, USA. As the Sun progresses toward solar maximum in the next few years, many more spectacular images of aurora are expected. November 4, 2012  New research from scientists using NASA's Spitzer Space Telescope suggests that a mysterious infrared glow across our whole sky is coming from stray stars torn from galaxies. That glow, known as the cosmic infrared background (CIB), has mysterious sources either too far away or too individually faint (or both) to resolve. Astronomers have long hoped that the CIB might tell something about the very first stars and galaxies that set the universe alight. But a new paper published last week in Nature suggests that finding such early evidence might be much harder than previously thought. When galaxies grow, they merge and become gravitationally tangled in a violent process that results in streams of stars being ripped away from the galaxies. Such streams, called tidal tails, can be seen in this artist's concept. Scientists say that Spitzer is picking up the collective glow of stars such as these, which linger in the spaces between galaxies. This artwork is adapted, in part, from galaxy images obtained from the NASA/ESA Hubble Space Telescope. Image credit: NASA/JPL-Caltech. November 3, 2012  How and why are all these stars forming? Found among the Small Magellanic Cloud's (SMC's) clusters and nebulae NGC 346 is a star forming region about 200 light-years across, pictured above by the Hubble Space Telescope. A satellite galaxy of the Milky Way, the Small Magellanic Cloud (SMC) is a wonder of the southern sky, a mere 210,000 light-years distant in the constellation of the Toucan (Tucana). Exploring NGC 346, astronomers have identified a population of embryonic stars strung along the dark, intersecting dust lanes visible here on the right. Still collapsing within their natal clouds, the stellar infants' light is reddened by the intervening dust. A small, irregular galaxy, the SMC itself represents a type of galaxy more common in the early Universe. But these small galaxies are thought to be a building blocks for the larger galaxies present today. Within the SMC, stellar nurseries like NGC 346 are also thought to be similar to those found in the early Universe. November 2, 2012  At the center of our Milky Way Galaxy, a mere 27,000 light-years away, lies a black hole with 4 million times the mass of the Sun. Fondly known as Sagittarius A* (pronounced A-star), the Milky Way's black hole is fortunately mild-mannered compared to the central black holes in distant active galaxies, much more calmly consuming material around it. From time to time it does flare-up, though. A recent outburst lasting several hours is captured in this series of premier X-ray images from the orbiting Nuclear Spectroscopic Telescope Array (NuSTAR). Launched last June 13, NuSTAR is the first to provide focused views of the area surrounding Sgr A* at X-ray energies higher than those accessible to Chandra and XMM observatories. Spanning two days of NuSTAR observations, the recent flare sequence is illustrated in the panels at the far right. X-rays are generated in material heated to over 100 million degrees Celsius, accelerated to nearly the speed of light as it falls into the Miky Way's central black hole. The main inset X-ray image spans about 100 light-years. In it, the bright white region represents the hottest material closest to the black hole, while the pinkish cloud likely belongs to a nearby supernova remnant. November 1, 2012  The suggestively shaped Witch Head Nebula is a reflection nebula and is associated with the bright star Rigel in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula spans about 50 light-years and is composed of interstellar dust grains reflecting Rigel's starlight. In this cosmic portrait, the blue color of the Witch Head Nebula and of the dust surrounding Rigel is caused not only by Rigel's intense blue starlight but because the dust grains scatter blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in Earth's atmosphere are molecules of nitrogen and oxygen. Rigel, the Witch Head Nebula, and gas and dust that surrounds them lie about 800 light-years away. October 31, 2012  Described as a "dusty curtain" or "ghostly apparition", mysterious reflection nebula VdB 152 really is very faint. Far from your neighborhood on this Halloween Night, the cosmic phantom is nearly 1,400 light-years away. Also catalogued as Ced 201, it lies along the northern Milky Way in the royal constellation Cepheus. Near the edge of a large molecular cloud, pockets of interstellar dust in the region block light from background stars or scatter light from the embedded bright star giving parts of the nebula a characteristic blue color. Ultraviolet light from the star is also thought to cause a dim reddish luminescence in the nebular dust. Though stars do form in molecular clouds, this star seems to have only accidentally wandered into the area, as its measured velocity through space is very different from the cloud's velocity. This deep telescopic image of the region spans about 7 light-years. October 30, 2012  Lake Tekapo on South Island in New Zealand is arguably one of best night sky locations in the Southern Hemisphere. The significance of its pristine night sky without light pollution is recognised world-wide and is being included in the list of UNESCO Starlight Reserves. This shot centres around the setting milky way, upside down to how most northern are used to seeing it; this how the milky way looks like when deep in the southern hemisphere. Lake Tekapo has water so clear that most of the stars and the milky way would be visible in the mirror-like reflection of the waters. October 29, 2012  Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of a binary star system. Internal winds emanating from the central stars, visible in the center, have been measured in excess of 1000 kilometers per second. These winds expand the nebula, flow along the nebula's walls, and cause waves of hot gas and dust to collide. Atoms caught in these colliding shocks radiate light shown in the above representative-color picture by the Hubble Space Telescope. The Red Spider Nebula lies toward the constellation of the Archer (Sagittarius). It's distance is not well known but has been estimated by some to be about 4,000 light-years. October 28, 2012  This colorful cosmic portrait features glowing gas and obscuring dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia. The nebula's colors were created by adopting the Hubble false-color palette for mapping narrow emission from oxygen, hydrogen, and sulfur atoms to blue, green and red colors, and further blending the data with images of the region recorded through broadband filters. Not far on the sky from the famous Double Star Cluster in Perseus, IC 1795 is itself located next to IC 1805, the Heart Nebula, as part of a complex of star forming regions that lie at the edge of a large molecular cloud. Located just over 6,000 light-years away, the larger star forming complex sprawls along the Perseus spiral arm of our Milky Way Galaxy. At that distance, this picture would span about 70 light-years across IC 1795. October 27, 2012  Supernova remnant Cassiopeia A (Cas A) is a comfortable 11,000 light-years away. Light from the Cas A supernova, the death explosion of a massive star, first reached Earth just 330 years ago. The expanding debris cloud spans about 15 light-years in this composite X-ray/optical image, while the bright source near the center is a neutron star (inset illustration) the incredibly dense, collapsed remains of the stellar core. Still hot enough to emit X-rays, Cas A's neutron star is cooling. In fact, 10 years of observations with the orbiting Chandra X-ray observatory find that the neutron star is cooling rapidly, so rapidly that researchers suspect a large part of the neutron star's core is forming a frictionless neutron superfluid. The Chandra results represent the first observational evidence for this bizarre state of neutron matter. More can be read about superfluids at The Chandra's site or Science Daily. October 26, 2012  Every book has a first page and every catalog a first entry. And so this lovely blue cosmic cloud begins the van den Bergh Catalog (vdB) of stars surrounded by reflection nebulae. Interstellar dust clouds reflecting the light of the nearby stars, the nebulae usually appear blue because scattering by the dust grains is more effective at shorter (bluer) wavelengths. The same type of scattering gives planet Earth its blue daytime skies. Van den Bergh's 1966 list contains a total of 158 entries more easily visible from the northern hemisphere, including bright Pleiades cluster stars and other popular targets for astroimagers. Less than 5 light-years across, VdB1 lies about 1,600 light-years distant in the constellation Cassiopeia. Also on this scene, two intriguing nebulae at the right show loops and outflow features associated with the energetic process of star formation. Within are extremely young variable stars V633 Cas (top) and V376 Cas. October 25, 2012  Braided, serpentine filaments of glowing gas suggest this nebula's popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away in the constellation Gemini. Like its mythological namesake, the nebula is associated with a dramatic transformation. The planetary nebula phase represents a final stage in the evolution of low mass stars like the sun, as they transform themselves from red giants to hot white dwarf stars and in the process shrug off their outer layers. Ultraviolet radiation from the hot star powers the nebular glow. The Medusa's transforming star is near the center of the overall bright crescent shape. In this deep telescopic view, fainter filaments clearly extend below and to the left of the bright crescent region. The Medusa Nebula is estimated to be over 4 light-years across. October 24, 2012  The large stellar association cataloged as NGC 206 is nestled within the dusty arms of neighboring spiral galaxy Andromeda (M31), 2.5 million light-years distant. Seen near the center of this gorgeous close-up of the southwestern extent of Andromeda's disk, the bright, blue stars of NGC 206 indicate its youth. Its youngest massive stars are less than 10 million years old. Much larger than the clusters of young stars in the disk of our Milky Way galaxy known as open or galactic clusters, NGC 206 spans about 4,000 light-years. That's comparable in size to the giant stellar nurseries NGC 604 in nearby spiral M33 and the Tarantula Nebula, in the Large Magellanic Cloud. October 23, 2012  Normal cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms. Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate. Such pockets may occur in turbulent air near a thunderstorm. Resulting mammatus clouds can appear especially dramatic if sunlit from the side. These mammatus clouds were photographed over Regina, Saskatchewan, Canada during the past summer. October 22, 2012   The sky toward the center of our Galaxy is filled with a wide variety of celestial wonders, many of which are visible from a dark location with common binoculars. Constellations near the Galactic Center include Sagittarius, Libra, Scorpius, Scutum, and Ophiuchus. Nebulas include Messier objects M8, M16, M20, as well as the Pipe and Cat's Paw nebulas. Visible open star clusters include M6, M7, M21, M23, M24, and M25, while globular star cluster M22 is also visible. A hole in the dust toward the Galactic Center reveals a bright region filled with distant stars known as Baade's Window, which is visible between M7 and M8. Moving your cursor over the above image the will bring up an un-annotated version. October 21, 2012  One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming. Light takes about 1,500 years to reach us from the Horsehead Nebula. The above image was taken with the 0.9-meter telescope at Kitt Peak National Observatory. October 20, 2012  Ghostly apparitions of two fundamental planes in planet Earth's sky span this October all-sky view. The scene was captured from a lakeside campsite under dark skies in northern Maine, USA. In it, the plane of our Milky Way Galaxy arcs above faint airglow along the horizon. Zodiacal light, a band of dust scattering sunlight along the solar system's ecliptic plane, stretches almost horizontally across the wide field and intersects the Milky way near a point marked by bright planet Jupiter. Right of Jupiter, past the Pleiades star cluster, is the brightening of the Zodiacal band known as the Gegenschein, also visible to the eye on that dark night. Rising above the distant mountains, Orion the hunter is reflected in the lake's calm waters. October 19, 2012  NGC 2623 is really two galaxies that are becoming one. Seen to be in the final stages of a titanic galaxy merger, the pair lies some 300 million light-years distant toward the constellation Cancer. The violent encounter between two galaxies that may have been similar to the Milky Way has produced widespread star formation near a luminous core and along eye-catching tidal tails. Filled with dust, gas, and young blue star clusters, the opposing tidal tails extend well over 50,000 light-years from the merged nucleus. Likely triggered by the merger, accretion by a supermassive black hole drives activity within the nuclear region. The star formation and its active galactic nucleus make NGC 2623 bright across the spectrum. This sharp cosmic snapshot of NGC 2623 (aka Arp 243) is based on Hubble Legacy Archive image data that also reveals even more distant background galaxies scattered through the field of view. October 18, 2012  Normally faint and elusive, the Jellyfish Nebula is caught in this alluring, false-color, telescopic view. Flanked by two bright stars, Mu and Eta Geminorum, at the foot of a celestial twin, the Jellyfish Nebula is the brighter arcing ridge of emission with dangling tentacles below and right of center. In fact, the cosmic jellyfish is seen to be part of bubble-shaped supernova remnant IC 443, the expanding debris cloud from a massive star that exploded. Light from the explosion first reached planet Earth over 30,000 years ago. Like its cousin in astrophysical waters the Crab Nebula supernova remnant, IC 443 is known to harbor a neutron star, the remnant of the collapsed stellar core. Emission nebula Sharpless 249 fills the field at the upper left. The Jellyfish Nebula is about 5,000 light-years away. At that distance, this image would be about 300 light-years across. The color scheme used in the narrowband composite was made popular in Hubble Space Telescope images, mapping emission from oxygen, hydrogen, and sulfur atoms to blue, green and red colors. October 17, 2012  Sometimes both heaven and Earth erupt. Colorful aurorae erupted unexpectedly earlier this month, with green aurora appearing near the horizon and brilliant bands of red aurora blooming high overhead. A bright Moon lit the foreground of this picturesque scene, while familiar stars could be seen far in the distance. With planning, the careful astrophotographer shot this image mosaic in the field of White Dome Geyser in Yellowstone National Park in the western USA. Sure enough, just after midnight, White Dome erupted - spraying a stream of water and vapor many meters into the air. Geyser water is heated to steam by scalding magma several kilometers below, and rises through rock cracks to the surface. About half of all known geysers occur in Yellowstone National Park. Although the geomagnetic storm that created these aurorae has since subsided, eruptions of White Dome Geyser continue about every 30 minutes. October 16, 2012   What's happening around that star? An unusual spiral structure has been discovered around the Milky Way star R Sculptoris, a red giant star located about 1,500 light years away toward the constellation of the Sculptor (Sculptoris). The star was observed with the new Atacama Large Millimeter/submillimeter Array (ALMA), the most powerful telescopic array observing near millimeter wavelengths, that part of the spectrum situated well beyond red light and between microwaves and radio waves. Data from ALMA observations was used to create a 3D visualization of the gas and dust immediately surrounding the star. A digital slice through this data showed the unexpected spiral structure. Although unusual, a similar spiral pattern was discovered in visible light recently around LL Pegasi in the second picture. Upon analyzing the data, a hypothesis was drawn that the red giant star in R Sculptoris might be puffing gas toward an unseen binary companion star. The dynamics of this system might be particularly insightful because it may be giving clues as to how giant stars evolve toward the end of their lives - and so release some constituent elements back to the interstellar medium so that new stars may form. October 15, 2012  Does this strange dark ball look somehow familiar? If so, that might be because it is our Sun. In the above image, a detailed solar view was captured originally in a very specific color of red light, then rendered in black and white, and then color inverted. Once complete, the resulting image was added to a starfield, then also color inverted. Visible in the above image of the Sun are long light filaments, dark active regions, prominences peaking around the edge, and a moving carpet of hot gas. The surface of our Sun has become a particularly busy place over the past two years because it is now nearing Solar Maximum, the time when its surface magnetic field is wound up the most. Besides an active Sun being so picturesque, the plasma expelled can also become picturesque when it impacts the Earth's magnetosphere and creates auroras. October 14, 2012  What did the first galaxies look like? To help answer this question, the Hubble Space Telescope has just finished taking the eXtreme Deep Field (XDF), the deepest image of the universe ever taken in visible light. Pictured above, the XDF shows a sampling of some of the oldest galaxies ever seen, galaxies that formed just after the dark ages, 13 billion years ago, when the universe was only a few percent of its present age. The Hubble Space Telescope's ACS camera and the infrared channel of the WFPC3 camera took the image. Combining efforts spread over 10 years, the XDF is more sensitive, in some colors, than the original Hubble Deep Field (HDF), the Hubble Ultra Deep Field (HUDF) completed in 2004, and the HUDF Infrared completed in 2009. Astronomers the world over will likely study the XDF for years to come to better understand how stars and galaxies formed in the early universe. A higher resolution image: October 13, 2012  Spiky stars and spooky shapes abound in this deep cosmic skyscape. Its well-composed field of view covers about 2 Full Moons on the sky toward the constellation Pegasus. Of course the brighter stars show diffraction spikes, the commonly seen effect of internal supports in reflecting telescopes, and lie well within our own Milky Way galaxy. The faint but pervasive clouds of interstellar dust ride above the galactic plane and dimly reflect the Milky Way's combined starlight. Known as high latitude cirrus or integrated flux nebulae they are associated with molecular clouds. In this case, the diffuse cloud cataloged as MBM 54, less than a thousand light-years distant, fills the scene. Other galaxies far beyond the Milky Way are visible through the ghostly apparitions, including the striking spiral galaxy NGC 7497 some 60 million light-years away. Seen almost edge-on near the center of the field, NGC 7497's own spiral arms and dust lanes echo the colors of the Milky Way's stars and dust. October 12, 2012  In myth, Atlas holds up the heavens, but in this scene they seem to pivot around a lighthouse beacon. Photographed with a camera fixed to a tripod, the well-planned 30 minute exposure records star trails in the northern sky, reflecting the daily rotation of planet Earth. Hidden behind the top of the prominent Nauset Lighthouse on Cape Cod, Massachusetts, USA, the North Celestial Pole is at the center of all the star trail arcs. Making a complete circle, 360 degrees, in 24 hours, the star trail arcs cover 15 degrees each hour or 7.5 degrees in thirty minutes. Foreground lighting is courtesy of September 23rd's first quarter moonlight. October 11, 2012  North America at night is easy to recognize in this view of our fair planet from orbit, acquired by the Suomi-NPP satellite on October 8. The spectacular waves of visible light emission rolling above the Canadian provinces of Quebec and Ontario in the upper half of the frame are the Aurora Borealis or northern lights. Encircling the poles and extending to lower latitudes, impressive aurorae seen during the past few days are due to strong geomagnetic storms. The storms were triggered by a solar coronal mass ejection on October 4/5, impacting Earth's magnetosphere some three days later. The curtains of light, shining well over 100 kilometers above the surface, are formed as charged particles accelerated in the magnetosphere excite oxygen and nitrogen in the upper atmosphere. October 10, 2012  How could a galaxy become shaped like a ring? Even more strange: how could two? The rim of the blue galaxy pictured on the right shows an immense ring-like structure 30,000 light years in diameter composed of newly formed, extremely bright, massive stars. This blue galaxy is part of the interacting galaxy system known as Arp 147, and shows a ring because it has recently collided with the other galaxy in the frame, the red galaxy on the left. Unusually, even this red galaxy shows a ring like band, although it is seen nearly edge-on. When galaxies collide, they pass through each other - their individual stars rarely come into contact. Clouds of interstellar gas and dust become condensed, causing a wave of star formation to move out from the impact point like a ripple across the surface of a pond. The above image was taken last week by NASA's Hubble Space Telescope to demonstrate the ability of its Wide Field Planetary Camera 2 after some recent technical difficulties. October 9, 2012  It's easy to get lost following the intricate filaments in this detailed mosaic image of faint supernova remnant Simeis 147 (S147). Also cataloged as Sh2-240, it covers nearly 3 degrees or 6 full moons on the sky. That's about 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years. Anchoring the frame at the right, bright star Elnath (Beta Tauri) is seen towards the boundary of the constellations Taurus and Auriga, almost exactly opposite the galactic center in planet Earth's sky. This sharp composite includes image data taken through a narrow-band filter to highlight emission from hydrogen atoms tracing the shocked, glowing gas. The supernova remnant has an estimated age of about 40,000 years, meaning light from the massive stellar explosion first reached Earth 40,000 years ago. But the expanding remnant is not the only aftermath. The cosmic catastrophe also left behind a spinning neutron star or pulsar, all that remains of the original star's core. October 8, 2012  Ghostly in appearance, Abell 39 is a remarkably simple, spherical nebula about five light-years across. Well within our own Milky Way galaxy, the cosmic sphere is roughly 7,000 light-years distant toward the constellation Hercules. Abell 39 is a planetary nebula, formed as a once sun-like star's outer atmosphere was expelled over a period of thousands of years. Still visible, the nebula's central star is evolving into a hot white dwarf. Although faint, the nebula's simple geometry has proven to be a boon to astronomers exploring the chemical abundances and life cycles of stars. In this deep image recorded under dark night skies, very distant background galaxies can be found - some visible right through the nebula itself. October 7, 2012  The 16th century Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two fuzzy cloud-like objects easily visible to southern hemisphere skygazers are known as the Clouds of Magellan, now understood to be satellite galaxies of our much larger, spiral Milky Way galaxy. About 160,000 light-years distant in the constellation Dorado, the Large Magellanic Cloud (LMC) is seen here in a remarkably deep, colorful composite image, starlight from the central bluish bar contrasting with the telltale reddish glow of ionized atomic hydrogen gas. Spanning about 15,000 light-years or so, it is the most massive of the Milky Way's satellite galaxies and is the home of the closest supernova in modern times, SN 1987A. The prominent patch at top left is 30 Doradus, also known as the magnificent Tarantula Nebula. The giant star-forming region is about 1,000 light-years across. October 6, 2012  Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta 1 Orionis C powers the complex star forming region's entire visible glow. About three million years old, the Orion Nebula Cluster was even more compact in its younger years and a recent dynamical study indicates that runaway stellar collisions at an earlier age may have formed a black hole with more than 100 times the mass of the Sun. The presence of a black hole within the cluster could explain the observed high velocities of the Trapezium stars, The Orion Nebula's distance of some 1500 light-years would make it the closest known black hole to planet Earth. October 5, 2012  What's happening behind that mountain? A convergence of variable sky spectacles. One night in mid-September near Tromsø, Norway, high red aurora could be seen shimmering through lower green aurora in a way that created a striking and somewhat unusual violet glow. Suddenly, though, the sky flashed with the brightest fireball the astrophotographer had ever seen, as a small pebble from outer space violently crashed into the Earth's atmosphere. The glow illuminated the distant mountain peak known as Otertinden of the Lyngen Alps. The bright meteor, which coincidently disappeared behind the same mountain, was also reflected in the foreground Signalelva River. Although you might consider yourself lucky to see either an aurora or a bright meteor, pictures of them together have been recorded several times previously. October 4, 2012  Source: A mere seven hundred light years from Earth, in the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final phase of stellar evolution. A total of 58 hours of exposure time have gone in to creating this deep view of the nebula. Accumulating narrow band data from emission lines of hydrogen atoms in red and and oxygen atoms in blue-green hues, it shows remarkable details of the Helix's brighter inner region, about 3 light-years across, but also follows fainter outer halo features that give the nebula a span of well over six light-years. The white dot at the Helix's center is this Planetary Nebula's hot, central star. A simple looking nebula at first glance, the Helix is now understood to have a surprisingly complex geometry. October 3, 2012   Source: Sometimes it's hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing like it. As the ever changing auroras evolved, huge shapes spread across the sky morphed from one familiar form into another, including what looked to be the head of a goat (shown above), the head of an elephant, a strange green-tailed comet, and fingers on a celestial hand. Even without the aurora, the sky would be notable for the arching band of our Milky Way Galaxy and the interesting field of stars, nebulas, and galaxies. In contrast, in the foreground is a farm house in Tasiusaq, Kujalleq. Greenland. The Shelios project exists not only to observe auroras but to motivate students to consider a career in science. October 2, 2012  Fresh evidence of an ancient stream has been found on Mars. The robotic rover Curiosity has run across unusual surface features that carry a strong resemblance to stream banks on Earth. Visible in the above image, for example, is a small overhanging rock ledge that was quite possibly created by water erosion beneath. The texture of the ledge appears to be a sedimentary conglomerate, the dried remains of many smaller rocks stuck together. Beneath the ledge are numerous small pebbles, possibly made smooth by tumbling in and around the once-flowing stream. Pebbles in the streambed likely fell there as the bank eroded. Circled at the upper right is a larger rock possibly also made smooth by stream erosion. Curiosity has now discovered several indications of dried streambeds on Mars on its way to its present location where it will be exploring the unusual conjunction of three different types of landscape. October 1, 2012  Could this dim spot brighten into one of the brightest comets ever? It's possible. Alternatively, the comet could break up when it gets closer to the Sun, or brighten much more modestly. Sky enthusiasts the world over are all abuzz, though, from the more optimistic speculations -- that the newly discovered C/2012 S1 (ISON) could develop a spectacular tail or briefly approach the brightness of the full Moon toward the end of 2013. Comet ISON currently is very faint but is just visible at magnitude 18 in the above image. The comet, discovered just over a week ago from Russia by Vitali Nevski (Belarus) and Artyom Novichonok (Russia), is currently falling toward the Sun from between the orbits of Jupiter and Saturn. In early 2013 October it will pass very near Mars and possibly be visible to rovers and orbiting spacecraft. Comet ISON appears on course to achieve sungrazer status as it passes within a solar diameter of Sun's surface in late 2013 November. Whatever survives will then pass nearest the Earth in late 2013 December. Astronomers around the world will be tracking this large dirty snowball closely to better understand its nature and how it might evolve during the next 15 months. September 30, 2012  Galaxies don't normally look like this. NGC 6745 actually shows the results of two galaxies that have been colliding for only hundreds of millions of years. Just off the above digitally sharpened photograph to the lower right is the smaller galaxy, moving away. The larger galaxy, pictured above, used to be a spiral galaxy but now is damaged and appears peculiar. Gravity has distorted the shapes of the galaxies. Although it is likely that no stars in the two galaxies directly collided, the gas, dust, and ambient magnetic fields do interact directly. In fact, a knot of gas pulled off the larger galaxy on the lower right has now begun to form stars. NGC 6745 spans about 80 thousand light-years across and is located about 200 million light-years away. September 29, 2012  Like delicate cosmic petals, these clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula and dutifully cataloged as NGC 7023 this is not the only nebula in the sky to evoke the imagery of flowers. Still, this remarkable image shows off the Iris Nebula's range of colors and symmetries in impressive detail. Within the Iris, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the dusty clouds glow with a faint reddish photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. Infrared observations indicate that this nebula may contain complex carbon molecules known as PAHs. The bright blue portion of the Iris Nebula is about six light-years across. September 28, 2012  Bright star Markab anchors this dusty skyscape. At the top right corner of the frame, Markab itself marks a corner of an asterism known as the Great Square, found within the boundaries of the constellation Pegasus, the flying horse. The wide and deep telescopic view rides along for some 5 degrees or about 10 times the angular diameter of the Full Moon, with blue reflection nebulae scattered around the scene. And even though this line-of-sight looks away from the plane of our Milky Way galaxy, it covers a region known to be filled with nearby molecular clouds. The associated dust clouds, high latitude galactic cirrus, are less than 1,000 light-years distant. Still apparent, but far beyond the Milky Way, are background galaxies, like the prominent edge-on spiral NGC 7497 near picture center. September 27, 2012  Cosmic dust clouds sprawl across a rich field of stars in this sweeping telescopic vista near the northern boundary of Corona Australis, the Southern Crown. Probably less than 500 light-years away and effectively blocking light from more distant, background stars in the Milky Way, the densest part of the dust cloud is about 8 light-years long. At its tip (upper right) is a group of lovely reflection nebulae cataloged as NGC 6726, 6727, 6729, and IC 4812. A characteristic blue color is produced as light from hot stars is reflected by the cosmic dust. The smaller yellowish nebula (NGC 6729) surrounds young variable star R Coronae Australis. Magnificent globular star cluster NGC 6723 is toward the upper right corner of the view. While NGC 6723 appears to be part of the group, it actually lies nearly 30,000 light-years away, far beyond the Corona Australis dust clouds. September 26, 2012  It's not every day that a space shuttle lands at LAX. Although this was a first for the major Los Angeles airport hub, it was a last for the space shuttle Endeavour, as it completed its tour of California skies and landed, albeit atop a 747, for the last time. During its last flight the iconic shuttle and its chase planes were photographed near several of California's own icons including the Golden Gate Bridge in San Francisco, the Hollywood Sign, and the skyline of Los Angeles. Previously, in May, the space shuttle Enterprise was captured passing behind several of New York City's icons on its way to the Intrepid Sea, Air, & Space Museum. Pictured above, the piggybacking shuttle was snapped on approach last week to LAX as it crossed above and beyond a major Los Angeles street. Now retired, the space shuttles are all museum pieces, with the above shuttle scheduled to be towed along the streets of LA to the California Science Center. September 25, 2012  What surrounds the florid Rosette nebula? To better picture this area of the sky, the famous flowery emission nebula on the far right has been captured recently in a deep and dramatic wide field image that features several other sky highlights. Designated NGC 2237, the center of the Rosette nebula is populated by the bright blue stars of open cluster NGC 2244, whose winds and energetic light are evacuating the nebula's center. Below the famous flower, a symbol of Valentine's Day, is a column of dust and gas that appears like a rose's stem but extends hundreds of light years. Across the above image, the bright blue star just left and below the center is called S Monocerotis. The star is part of the open cluster of stars labelled NGC 2264 and known as the Snowflake cluster. To the right of S Mon is a dark pointy featured called the Cone nebula, a nebula likely shaped by winds flowing out a massive star obscured by dust. To the left of S Mon is the Fox Fur nebula, a tumultuous region created by the rapidly evolving Snowflake cluster. The Rosette region, at about 5,000 light years distant, is about twice as far away as the region surrounding S Mon. The entire field can be seen with a small telescope toward the constellation of the Unicorn (Monoceros). September 24, 2012  This shock wave plows through space at over 500,000 kilometers per hour. Moving toward to bottom of this beautifully detailed color composite, the thin, braided filaments are actually long ripples in a sheet of glowing gas seen almost edge on. Cataloged as NGC 2736, its narrow appearance suggests its popular name, the Pencil Nebula. About 5 light-years long and a mere 800 light-years away, the Pencil Nebula is only a small part of the Vela supernova remnant. The Vela remnant itself is around 100 light-years in diameter and is the expanding debris cloud of a star that was seen to explode about 11,000 years ago. Initially, the shock wave was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar gas. September 23, 2012  Yesterday was an equinox, a date when day and night are equal. Today, and every day until the next equinox, the night will be longer than the day in Earth's northern hemisphere, and the day will be longer than the night in Earth's southern hemisphere. An equinox occurs midway between the two solstices, when the days and nights are the least equal. The picture is a composite of hourly images taken of the Sun above Bursa, Turkey on key days from solstice to equinox to solstice. The bottom Sun band was taken during the winter solstice in 2007 December, when the Sun could not rise very high in the sky nor stay above the horizon very long. This lack of Sun caused winter. The top Sun band was taken during the summer solstice in 2008 June, when the Sun rose highest in the sky and stayed above the horizon for more than 12 hours. This abundance of Sun caused summer. The middle band was taken during the Vernal Equinox in 2008 March, but it is the same sun band that Earthlings saw yesterday, the day of the Autumnal Equinox. September 22, 2012  Today, the Sun crosses the celestial equator heading south at 14:49 Universal Time. An equinox (equal night), this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south. With the Sun on the celestial equator, Earth dwellers will experience nearly 12 hours of daylight and 12 hours of darkness. To celebrate, consider this careful record of the Sun's yearly journey through southern Austrian skies. The scene is composed of images made at the same time each day, capturing the Sun's position on dates from September 29, 2011 through September 9, 2012. The multiple suns trace an intersecting curve known as an analemma. In fact, the past year's two equinox dates correspond to the middle (not the intersection point) of the curve. The summer and winter solstices are at the top and bottom. Of course, many would also consider it a good idea to travel the mountain road toward the left, passing the vineyards along the way to reach the nearby town of Kitzeck and toast the equinox with a glass of wine. Near the roadside bench is a windmill-like klapotetz, traditionally used in this wine-growing region to keep the birds away. September 21, 2012  September's equinox arrives tomorrow as the Sun crosses the celestial equator heading south. The event marks the astronomical beginning of spring in the southern hemisphere and autumn in the north. And though the connection is still puzzling, the equinox seasons bring an increase in geomagnetic storms. So as northern nights grow longer, the equinox also heralds the arrival of a good season for aurora hunters. Recorded on September 20, these colorful northern lights were captured with camera and wide-angle lens near the Norwegian Sea coast outside Tromsø in Northern Norway. Shining at altitudes of 100 kilometers or so, the aurora rays are parallel, but perspective makes them appear to radiate from a vanishing point behind the silhouetted pine tree. Stars in this enchanting northern night include Polaris above and right of the tree top, and yellowish giant stars Shedar (Alpha Cassiopiae) to the left and Kochab (Beta Ursae Minoris) to the right. Bright Altair shines through the greenish auroral curtain at the lower left of the scene. September 20, 2012  An analemma is that figure-8 curve that you get when you mark the position of the Sun at the same time each day throughout planet Earth's year. In this case, 17 individual images taken at 0231 UT on dates between April 2 and September 16 follow half the analemma curve, looking east toward the rising sun and the Caspian sea from the boardwalk in the port city of Baku, Azerbaijan. With the sun nearest the horizon, those dates almost span the period between the 2012 equinoxes on March 20 and September 22. The northern summer Solstice on June 20 corresponds to the top of the figure 8 at the left, when the Sun stood at its northernmost declination. Of course, this year the exposure made on June 6 contained a little something extra. Slightly enhanced, the little black spot on the bright solar disk near the top of the frame is planet Venus, caught in a rare transit during this well-planned sunrise analemma project. September 19, 2012  Is it art? Earlier this month, space station astronaut Aki Hoshide (Japan) recorded this striking image while helping to augment the capabilities of the Earth-orbiting International Space Station (ISS). Visible in this outworldly assemblage is the Sun, the Earth, two portions of a robotic arm, an astronaut's spacesuit, the deep darkness of space, and the unusual camera taking the picture. This image joins other historic - and possibly artistic -- self-portraits taken previously in space. The Expedition 32 mission ended yesterday when an attached capsule undocked with the ISS and returned some of the crew to Earth. September 18, 2012 This shot of the Milky Way's galactic core was taken by one of my friends who went up to Algonquin Park this weekend to shoot the stars, as I went up north to Wasaga Beach to test my new tripod. He did not add any colour, but simply took 15 images via the Astrotrac star tracker he bought and stacked them. The picture was Shot on the Canon 5DMk2 and Zeiss 50mm at f2.8, ISO1600. The yellow glow at the bottom is light pollution from the distant town of Whitney. How many messier objects can you see in this photo? The spout of the Saggitarius Teapot is visible at the bottom left of this image, bordering the Saggitarius Star Cloud. September 17, 2012  What's happened to our Sun? Nothing very unusual -- it just threw a filament. At the end of last month, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME). The filament had been held up for days by the Sun's ever changing magnetic field and the timing of the eruption was unexpected. Watched closely by the Sun-orbiting Solar Dynamics Observatory, the resulting explosion shot electrons and ions into the Solar System, some of which arrived at Earth three days later and impacted Earth's magnetosphere, causing visible aurorae. Loops of plasma surrounding an active region can be seen above the erupting filament in the ultraviolet image. If you missed this auroral display please do not despair - over the next two years our Sun will be experiencing a solar maximum of activity which promises to produce more CMEs that induce more Earthly auroras. September 16, 2012  How old are Saturn's rings? No one is quite sure. One possibility is that the rings formed relatively recently in our Solar System's history, perhaps only about 100 million years ago when a moon-sized object broke up near Saturn. Evidence for a young ring age includes a basic stability analysis for rings, and the fact that the rings are so bright and relatively unaffected by numerous small dark meteor impacts. More recent evidence, however, raises the possibility that some of Saturn's rings may be billions of years old and so almost as old as Saturn itself. Inspection of images by the Saturn-orbiting Cassini spacecraft indicates that some of Saturn's ring particles temporarily bunch and collide, effectively recycling ring particles by bringing fresh bright ices to the surface. Seen here, Saturn's rings were imaged in their true colors by the robotic Cassini in late October. Icy bright Tethys, a moon of Saturn likely brightened by a sandblasting rain of ice from sister moon Enceladus, is visible in front of the darker rings. September 15, 2012  Inspired by the night skies of planet Earth in the International Year of Astronomy, photographer Larry Landolfi created this tantalizing fantasy view. The composited image suggests a luminous Milky Way is the heavenly extension of a country road. Of course, the name for our galaxy, the Milky Way (in Latin, Via Lactea), does refer to its appearance as a milky band or path in the sky. In fact, the word galaxy itself derives from the Greek for milk. Visible on moonless nights from dark sky areas, though not so bright or colorful as in this image, the glowing celestial band is due to the collective light of myriad stars along the plane of our galaxy, too faint to be distinguished individually. The diffuse starlight is cut by dark swaths of obscuring galactic dust clouds. Four hundred years ago, Galileo turned his telescope on the Milky Way and announced it to be "... a congeries of innumerable stars ..." September 14, 2012  Giant elliptical galaxy M60 and spiral galaxy NGC 4647 do look like an odd couple in this sharp cosmic portrait from the Hubble Space Telescope. But they are found in a region of space where galaxies tend to gather, on the eastern side of the nearby Virgo Galaxy Cluster. About 54 million light-years distant, bright M60's simpler egg-like shape is created by its randomly swarming older stars, while NGC 4647's young blue stars, gas and dust are organized into winding arms rotating in a flattened disk. Spiral NGC 4647 is estimated to be more distant than M60, some 63 million light-years away. Also known as Arp 116, the pair of galaxies may be on the verge of a significant gravitational encounter, though. M60 (aka NGC 4649) is about 120,000 light-years across. The smaller NGC 4647 spans around 90,000 light-years, about the size of our own Milky Way. September 13, 2012  In this crowded starfield covering over 2 degrees within the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. A compact star forming region, the cosmic Cocoon punctuates a long trail of obscuring interstellar dust clouds. Cataloged as IC 5146, the nebula is nearly 15 light-years wide, located some 4,000 light years away. Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by the young, hot stars and blue, dust-reflected starlight at the edge of an otherwise invisible molecular cloud. In fact, the bright star near the center of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it clears out a cavity in the molecular cloud's star forming dust and gas. But the long dusty filaments that appear dark in this visible light image are themselves hiding stars in the process of formation, seen at infrared wavelengths. September 12, 2012  M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius). M7 contains about 100 stars in total, is about 200 million years old, spans 25 light-years across, and lies about 1000 light-years away. The above deep exposure was taken from Hakos Farm in Namabia. The M7 star cluster has been known since ancient times, being noted by Ptolemy in the year 130 AD. Also visible are a dark dust cloud and literally millions of unrelated stars towards the Galactic center. September 11, 2012  Which part of this picture do you find more interesting -- the land or the sky? Advocates for the land might cite the beauty of the ancient domes of the Bungle Bungle Range in Western Australia. These picturesque domes appear as huge layered beehives and are made of sandstones and conglomerates deposited over 350 million years ago. Advocates for the sky might laud the beauty of the Milky Way's central band shown arching from horizon to horizon. The photogenic Milky Way band formed over 10 billion years ago and now includes many well-known nebulae and bright stars. Fortunately, you don't have to decide and can enjoy both together in this beautiful 8-frame panorama taken from the dark skies of Purnululu National Park about two months ago. September 10, 2012  Curiosity is on the move across Mars -- but where is it going? The car-sized rover's path after 29 Martian days on the surface is shown on the above map. Curiosity is still almost 300 meters from its first major destination, though, a meeting of different types of terrain called Glenelg and visible on the image right. It may take Curiosity two months or so to get to Glenelg as it stops to inspect interesting rocks or landscape features along the way. The above image was taken about one week ago from high up by the HiRise camera onboard the robotic Mars Reconnaissance Orbiter. September 9, 2012  The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of absorbing dust and glowing gas. To bring out details of the Horsehead's pasture, amateur astronomers at the Star Shadow Remote Observatory in New Mexico, USA fixed a small telescope on the region for over seven hours filtering out all but a very specific color of red light emitted by hydrogen. They then added the image to a full color frame taken over three hours. The resulting spectacular picture details an intricate tapestry of gaseous wisps and dust-laden filaments that were created and sculpted over eons by stellar winds and ancient supernovas. The Horsehead Nebula lies 1,500 light years distant towards the constellation of Orion. Two stars from the Orion's Belt can be found in the above image. September 8, 2012  Launched on a grand tour of the outer planets in 1977, by good fortune the twin Voyager spacecraft were also headed in the general direction of the Sun's motion relative to nearby stars. Thirty five years later, Voyager 1 appears to be nearing the boundary of the Sun's heliosphere and interstellar space. Of course the heliosphere is the realm of the Sun defined by the influence of the solar wind and the Sun's magnetic field. But how can you tell when your spacecraft crosses the boundary into interstellar space? One clue would be a sudden increase in the detection of energetic cosmic rays. The high energy particles stream through interstellar space accelerated by distant supernovae in our galaxy, but are normally deflected or slowed by the heliosphere. Covering a 12 month period (September 2011 to 2012), this plot does show a dramatic increase in the rate of cosmic ray particle detection in past months by the Voyager 1 spacecraft. Voyager 1 is now 18 billion kilometers (17 light hours, 122 Astronomical Units) from the Sun and may soon be the first spacecraft from Earth to enter the realm of the stars. September 7, 2012  South of Antares, in the tail of the nebula-rich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, radiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow, dominated by the red emission of hydrogen. At an estimated distance of 6,000 light-years, the region shown is about 250 light-years across, spanning an area equivalent to four full moons on the sky. The nebula is also cataloged as Gum 56 for Australian astronomer Colin Stanley Gum, but seafood-loving astronomers might know this cosmic cloud as The Prawn Nebula. September 6, 2012  In this serene night skyscape, the Milky Way's graceful arc stretches over prominent peaks in the Italian Alps known as Tre Cime di Lavaredo. A 180 degree wide-angle panorama made in four exposures on August 24, the scene does look to the north and the sky is suffused with an eerie greenish light. Still, the subtle glowing bands are not aurorae, but airglow. Unlike aurorae powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction, and found around the globe. The chemical energy is provided by the Sun's extreme ultraviolet radiation. Like aurorae, the greenish hue of this airglow does originate at altitudes of 100 kilometers or so dominated by emission from excited oxygen atoms. More easily seen near the horizon, airglow keeps the night sky from ever being completely dark. September 5, 2012  Does air glow? It does, but it is usually hard to see. When conditions are right, however, a faint glow about 90 kilometers up can be observed, most easily with a wide-angle long-duration camera exposure. The same airglow can also frequently be seen looking down - in pictures taken from Earth orbit - as a faint arc hovering above the surface. Pictured above between the beige clouds, above the curving Earth, behind the streaking airplane, and in front of the sparkling stars are some green bands of airglow. The glow is predominantly created by the excitation of atoms by ultraviolet light from the Sun, with the bands resulting from density fluctuations caused by upward moving atmospheric gravity waves. The above image was taken in mid-July above Weikersheim, Germany. Lightning and aurorae can also cause air to glow, but result from particle collisions and are more fleeting. September 4, 2012  Should you be worried about hurricanes? To find out, it is useful to know where hurricanes have gone in the past. The above Earth map shows the path of every hurricane reported since 1851, Although striking, a growing incompleteness exists in the data the further one looks back in time. The above map graphically indicates that hurricanes - sometimes called cyclones or typhoons depending on where they form - usually occur over water, which makes sense since evaporating warm water gives them energy. The map also shows that hurricanes never cross - or even occur very near - the Earth's equator, since the Coriolis effect goes to zero there, and hurricanes need the Coriolis force to circulate. The Coriolis force also causes hurricane paths to arc away from the equator. Although incompleteness fogs long term trends and the prevalence of hurricanes remains a topic of research, evidence is accumulating that hurricanes are, on the average, more common and more powerful in the North Atlantic Ocean over the past 20 years. September 3, 2012  Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades. (Editors' note: The prominent diffraction spikes are caused by the telescope itself and may be either distracting or provide aesthetic enhancement, depending on your point of view.) September 2, 2012  This graceful arc traces a Delta rocket climbing through Thursday's early morning skies over Cape Canaveral Air Force Station in Florida, USA. Snug inside the rocket's Centaur upper stage were NASA's twin Radiation Belt Storm Probes (RBSP), now in separate orbits within planet Earth's Van Allen radiation belts. Reflected in the Turn Basin from a vantage point about 3 miles from Space Launch Complex 41, the scene was captured in a composite of two exposures. One highlights the dramatic play of launch pad lighting, clouds, and sky. A subsequent 3 minute long exposure records the rocket's fiery trail. While most spacecraft try to avoid the radiation belts, named for their discoverer James Van Allen, RBSP's mission will be to explore their dynamic and harsh conditions. September 1, 2012  Rising at sunset, the gorgeous Full Moon of August 31 became the second Full Moon in a month. According to modern reckoning, that makes it a Blue Moon. In fact, parts of the Full Moon do look a little blue in this sharp lunar portrait. Taken just hours before the exact full phase in delightfully clear skies over Nottingham, UK, it features eye-catching bright rays extending from the prominent young crater Tycho in the Moon's southern hemisphere. The slightly color enhanced image also brings out subtle shades of blue, a real characteristic of terrain with a high content of titanium oxide and iron. The blue lunar terrain on the right includes the dark flat expanse of the Sea of Tranquility and the Apollo 11 landing site. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 29, 2012 -This is the time of year when the dim Little Dipper juts to the right from Polaris (its handle-end) during evening hours. The much brighter Big Dipper curls over high above it, "dumping water" into it. -This is also the time of year when Orion, declining in the southwest after dark, displays his three-star Belt more or less horizontally. Astro Picture of the Day March 29, 2012 Source: On March 27, five sounding rockets leapt into early morning skies from NASA's Wallops Flight Facility in Virginia. Part of the Anomalous Transport Rocket EXperiment (ATREX), begining at 4:58 am EDT the rockets launched consecutively at 80 second intervals. Releasing a chemical tracer they created luminous white clouds within Earth's ionosphere at altitudes above 60 to 65 miles, swept along by the poorly understood high-altitude jet stream. (Not the same jet stream that airliners fly through at altitudes of 5 to 6 miles.) Seen along the mid-atlantic region of the United States, the clouds drifted through starry skies, captured in this clear photograph from East Point, New Jersey. Looking south toward the launch site, the tantalizing celestial background includes the stars of Sagittarius, Scorpius, and the more permanent faint, white, luminous clouds of the Milky Way. Can you distinguish these constellations? |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
March 30, 2012 -First-quarter Moon (exact at 3:41 p.m. EDT). The Moon shines in the legs of Gemini, below Pollux and Castor and high above sinking Betelgeuse. -Saturn is high in the south by 1:00 a.m. near Spica. Astro Picture of the Day: March 30, 2012 Source: In this alluring night skyscape recorded on March 26, a young Moon stands over the distant western horizon in conjunction with brilliant planet Venus. In the foreground, the Colorado River glistens in moonlight as it winds through the Grand Canyon, seen from the canyon's southern rim at Lipan Point. The Grand Canyon is known as one of the wonders of planet Earth. Carved by the river, the enormous fissure is about 270 miles (440 kilometers) long, up to 18 miles (30 kilometers) wide and approaches 1 mile (1.6 kilometers) deep. On this date, wonders of the night sky included the compact Pleiades and V-shaped Hyades star clusters poised just above the Moon. Bright planet Jupiter is below the closer Moon/Venus pairing, near the western horizon. |
Re: Terry's Astronomy Thread.
These pictures are so amazing, keep em coming :')
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I spend more time looking at the night sky when I'm out at night thanks to this thread haha
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Thanks Winrar for the compliment! And i'm glad that you spend more time looking at the night sky hi19hi19, but has this thread helped you distinguish what some of the night time objects are? That's part of the goal of this thread.
What's in the sky tonight? March 31, 2012 -The Moon shines high in the southwest this evening. It forms a gently curving line (as seen from North America) with Pollux and Castor to its upper right and Procyon below it. Procyon is one of the 3 stars in the Winter Triangle, and as it sets earlier and earlier every day, it's an astronomical sign spring and summer are upon us. Astro Picture of the Day: March 31, 2012 Source: Meet M9. M9 is a globular cluster discovered by Charles Messier, and listed it as the 9th entry in his catalogue (hence Messier 9). He listed this globular cluster as a "Nebula, without star, in the right leg of Ophiuchus ...". Optics have improved since the 18th century however, and this 'starless nebula' has been found to contain over 300,000 stars within a diameter of 90 light years. It is some 25,000 light years distant near the central bulge of our milky way galaxy. This picture takes a look at the central 25 light years of the cluster. At least twice the age of the Sun and deficient in heavy elements, the cluster stars have colors corresponding to their temperatures, redder stars are cooler, bluer stars are hotter. Many of the cluster's cool red giant stars show a yellowish tint in the sharp Hubble view. Globular clusters are typically found -outside- the disk of spiral galaxies, and are evidence that a spiral galaxy was once more spherical in shape before flattening into a disk with a bulge. |
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What's in the sky tonight? April 1, 2012 -The Belt of Orion points left toward Sirius, and right toward Aldebaran and (farther on) brilliant Venus. The winter constellations continue to sink in the west as April rolls in. -Look for Venus to dance with the Pleiades between now and April 5! This is the best chance to understand the Pleiades' location in the sky and how they look like in general. -That V-Shaped cluster with the brilliant red star Alderbaran manning the top of the V is the other popular star cluster, the Hyades. It is much closer to us, and as such spans about 5 degrees of the sky. Aldebaran is actually not part of the cluster however, it's merely a red giant that happens to be in the line of sight between the Earth and the cluster. Astro Picture of the Day: April 1, 2012 Source: This rugged road through the dark Atacama Desert seems to lead skyward toward the bright stars and glowing nebulae of the southern Milky Way. If you follow the road you will get to Cerro Armazones peak in Chile, future construction site for the 40-meter class European Extremely Large Telescope. For now though, sliding your cursor across the image will identify wonders of the southern skies in view. The scene is dominated by the reddish glow of the Great Carina Nebula, one of our galaxy's largest star forming regions. In fact, the remarkable skyscape is not a composite of varying exposures or a photomontage. Far from sources of light pollution, the landscape illuminated by starlight and the Milky Way above were recorded by a modified digital camera and fast lens. The sensitive system captured both planet Earth and deep sky in a relatively short exposure. |
Re: Terry's Astronomy Thread.
Thank you to whoever mod or admin decided to sticky this thread. :D
What's in the sky tonight? April 2, 2012 -Venus is passing through the outskirts of the Pleiades this evening through Wednesday evening, as shown below. Binoculars or a wide-field telescope give a fine view of the delicate cluster behind Venus's overpowering glare. -The waxing gibbous Moon forms a slightly curving line with Mars and Regulus, as shown below. Astro Picture of the Day: April 2, 2012 Source: What's large and blue and can wrap itself around an entire galaxy? A gravitational lens mirage. Pictured above, the gravity of a luminous red galaxy (LRG) has gravitationally distorted the light from a much more distant blue galaxy. More typically, such light bending results in two discernible images of the distant galaxy, but here the lens alignment is so precise that the background galaxy is distorted into a horseshoe -- a nearly complete ring. Since such a lensing effect was generally predicted in some detail by Albert Einstein over 70 years ago, rings like this are now known as Einstein Rings. Although LRG 3-757 was discovered in 2007 in data from the Sloan Digital Sky Survey (SDSS), the image shown above is a follow-up observation taken with the Hubble Space Telescope's Wide Field Camera 3. Strong gravitational lenses like LRG 3-757 are more than oddities -- their multiple properties allow astronomers to determine the mass and dark matter content of the foreground galaxy lenses. |
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Wow, every image is breathtaking. Thank you for sharing :)
I'm getting into astronomy myself but unfortunately i live in one of the worst light polluted area's in the UK. I've managed to get a few decent views of Jupiter, Saturn and the Moon but i'm really interested in viewing some DSOs. Currently saving my pennies for a telescope upgrade and trying to locate a dark site near where i live. |
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What's in the Sky Tonight? April 3, 2012 -The Moon now forms the bottom point of a narrow triangle with Mars and Regulus, as shown below. -Venus is the closest it will come to the middle of the Pleiades. This evening for the Americas, Venus is passing just ½° southeast of Alcyone (the brightest Pleiad) and ¼° south of the Atlas-Pleione pair. Venus is magnitude –4.5, which means Alcyone, at magnitude 2.85, is 900 times fainter! -Saturn rises with Spica in Virgo late in the evening, clearly visible by midnight. Astro Picture of the Day: April 3, 2012 Source: Many stars form in clusters. Galactic or open star clusters are relatively young swarms of bright stars born together near the plane of our Milky Way Galaxy. Separated by about a degree on the sky, two nice examples are M46 (upper left) 5,400 light-years in the distance and M47 (lower right) only 1,600 light-years away toward the nautical constellation Puppis. Around 300 million years young M46 contains a few hundred stars in a region about 30 light-years across. Aged 80 million years, M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. But this portrait of stellar youth also contains an ancient interloper. The small, colorful patch of glowing gas in M46 of the same colour is actually the planetary nebula NGC 2438 - the final phase in the life of a sun-like star billions of years old. It is found near the bottom of M46 within our line of sight to the cluster. NGC 2438 is estimated to be only 3,000 light-years distant and likely represents a foreground object, only by chance appearing along our line of sight to youthful M46. |
Re: Terry's Astronomy Thread.
What's in the Sky Tonight?
April 4, 2012 -Two planet-and-star pairings mark the evening sky of spring 2012. After nightfall this week, Mars shines high in the south with Regulus to its right (by 5°). As evening advances, Saturn rises into view low in the east-southeast with Spica to its right (by 5½°). Astro Picture of the Day: April 4, 2012 Source: What's the closest active galaxy to planet Earth? That would be Centaurus A, only 11 million light-years distant. Spanning over 60,000 light-years, the peculiar elliptical galaxy is also known as NGC 5128. Forged in a collision of two otherwise normal galaxies, Centaurus A's fantastic jumble of young blue star clusters, pinkish star forming regions, and imposing dark dust lanes are seen here in remarkable detail. The colorful galaxy portrait was recorded under clear Chilean skies at the Cerro Tololo Inter-American Observatory. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. That process likely generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A. |
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Something suited for Astrophotography but not ridiculously priced as i know I'll be needing a good camera as well. |
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This is the United Kingdom. Use this to make out the difference between the different colours of the light pollution map.   Seeing as you are here, your best bet is to head southwest in order to find some good starry area. Find the road A487 until you get to Aberaeron which looks to be a small town you've never heard of before. If you go there and maybe slightly south of the town, and plant your telescope on a good, clear night, you should be very happy. This is a 3 hour trek according to google directions though. If you don't want to drive that far, you can try heading into the blue zone and head just west of Montgomery, which you can get to in just under 1 hr 45 minutes. Hope this helps! (But remember, you're from the UK and I'm not, so you may know a better way.) As for telescopes, do you have a budget limit on what you're willing to spend on a telescope? The spoiler will list telescopes under $250.00 that are good. Be prepared to spend a couple hundred, it is very rare to find something decent under $180. Depending on budget, I will list a few options taken straight from this article: http://www.skyandtelescope.com/equip.../69745547.html Orion XT4.5 Classic Dobsonian Orion Starblast 4.5 Astro Reflector Orion SpaceProbe 3 Altazimuth Reflector Orion Observer 70-mm Altazimuth Refractor Edmund Scientifics Astroscan My list is in order of most expensive to least expensive. The Astroscan Plus is the most expensive of the 5 that I am listing at $249.00 but is ultra portable in the sense that it is small. It has a field of view the equivalent of 6 full moons and the two eye pieces it comes with are 16x and 30x magnification. the 30x magnification will allow you to see Saturn's rings. This one is best for the moon, and nearby planets. If you want a stellar (astronomy pun!) telescope for a beginner, the Orion SkyQuest XT4.5 Classic Dobsonian Telescope retails for about $239.99 (I have found it here for $209 temporarily). Magnification with included eye pieces are 36x and 91x. The finder magnification is 6x. Fully assembled it weighs 17.6 lbs. Of the 30 reviews it has been given, 27 have rated it 5 stars, and it has also been recommended by SkyandTelescope. http://www.telescope.com/Telescopes/...yCategoryId=13 The Orion StarBlast 4.5 Astro Reflector Telescope is cheaper at $199 (on sale for $179.99) and has eye piece magnifications of 26x and 75x. Fully assembled it weighs 13.0 lbs. Link to it here: http://www.telescope.com/Telescopes/.../28/p/9814.uts The Orion SpaceProbe 3 Equitorial Reflector Telescope costs $149.99 and is best used for lunar and planetary viewing. the eye piece magnification is 28x and 70x and weighs 16.6 lbs when assembled. http://www.telescope.com/Telescopes/.../11/p/9843.uts The Orion Observer 70mm Altazimuth Refractor Telescope is more traditional looking in terms of how one would think a telescope looks like, and is much more budget friendly at $139.99 (on sale for $119.99). Also featuring eye pieces with 28x and 70x magnification, it only weighs 6.5 lbs when fully assembled. Because of this, it might be more difficult taking pictures through this one. Of the 5, I like the Orion StarBlast the best in this scenario. One of the biggest reasons for this is because it comes to you pre-assembled. It is $179 well spent! Keep in mind these are online orders. I will see if I can find these in a store somewhere, but I have a feeling they're likely to be priced higher at retail level. For additional telescope reading, refer to here (this page also includes a few great links to finding the first telescope for a specific need) : http://www.skyandtelescope.com/letsg.../12511616.html |
Re: Terry's Astronomy Thread.
This actually made me aware that I've never seen the milky way cause of light pollution....
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I do like the look of the Orion StarBlast and the fact it comes pre-assembled does sound good as mine was a pain in the ass. My current telescope is an Astromaster 130EQ : http://www.rothervalleyoptics.co.uk/celestron-astromaster-130-eq-md-telescope_d3424.html I've learned how to align it but am now interested in a computerised mount. My budget would be around £400-£600 and i maybe able to stretch a little further. Again, thank you for help mate. |
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http://www.telescope.com/Orion-StarB...on%20StarBlast Take a look at this telescope. It comes with a computer object finder which becomes functional after you align it with 2 very bright stars. Its database contains thousands of objects that you can punch in and the telescope will move to that specific spot in the sky that it should be in (provided it's been aligned correctly). I am getting ready to leave for class now, and I need to prepare for my astronomy final exam tomorrow, and I can go into further detail if you want. But this is definitely one to take a look at. As an added bonus it's one of Skyandtelescope's hot products of 2010 (means it's very good.) I suggest taking a look at the video gallery and customer reviews, they're quite helpful and sometimes customer reviews have photos taken with the product! |
Re: Terry's Astronomy Thread.
And as I'm posting this, I'm getting ready to depart for my astronomy exam. I'll find out how I did next week. I added some new features to the thread throughout yesterday.
What's in the Sky Tonight? April 5, 2012 -The Moon is nearly full this evening. Look left of it for Gamma (γ) Virginis (Porrima), a tight telescopic double star. (Its separation is 1.8 arcseconds this spring; it's widening year by year). Look farther lower left of the Moon for steady-shining Saturn and twinkly Spica, as shown here. And look to the Moon's lower right for the four-star pattern of the constellation Corvus, the Crow. Astro Picture of the Day: April 5, 2012 Source: Sweeping from the eastern to western horizon, this 360 degree panorama follows the band of zodiacal light along the solar system's ecliptic plane. Dust scattering sunlight produces the faint zodiacal glow that spans this fundamental coordinate plane of the celestial sphere, corresponding to the apparent yearly path of the Sun through the sky and the plane of Earth's orbit. The fascinating panorama is a mosaic of images taken from dusk to dawn over the course of a single night at two different locations on Mauna Kea. The lights of Hilo, Hawaii are on the eastern (left) horizon, with the Subaru and twin Keck telescope structures near the western horizon. On that well chosen moonless night, Venus was shining as the morning star just above the eastern horizon, and Saturn was close to opposition. In fact, Saturn is seen immersed in a brightening of the zodiacal band known as the gegenschein. The gegenschein also lies near 180 degrees in elongation or angular distance from the Sun along the ecliptic. In the mosaic projection, the plane of our Milky Way Galaxy runs at an angle, crossing the horizontal band of zodiacal light above the two horizons. Nebulae, stars, and dust clouds of the bulging galactic center are rising in the east. |
Re: Terry's Astronomy Thread.
Oh man, one night I'd love to come to the east side and see what you're probably seeing every night.
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Hope your exam went okay as well mate. |
Re: Terry's Astronomy Thread.
As far as cameras go, the Canon 20Da, while I'm not sure WHERE to get it, is designed specifically for astrophotography, being that it doesn't filter out infrared light and will produce higher contrast and sharper photos.
http://en.wikipedia.org/wiki/Eos_20d#EOS_20Da However apparently now there's a Canon 60Da which clearly would be more desirable for basically the same cost http://en.wikipedia.org/wiki/Canon_EOS_60Da#EOS_60Da Though these are quite pricey. What is your budget for the photographic end of this? With that telescope all you'll be needing is a body for the camera and either using it with a remote shutter, or simply plugging the camera into a laptop and doing it live. EDIT: Woops, didn't read that you've already been doing astrophotography. Either way, some more info if your camera isn't up to par :P |
Re: Terry's Astronomy Thread.
What's in the Sky Tonight?
April 6, 2012 -Full Moon (exact at 3:19 p.m. EDT). This evening the Moon shines in the east with Spica a little to its left and Saturn farther left — a pretty lineup, as shown here. Farther to the Moon's right, look for the four-star pattern of Corvus, the Crow. Much farther to the upper left (outside the picture here) is bright Arcturus, the "Spring Star." -Mars (magnitude –0.7) shines bright fire-orange under the belly of Leo. Regulus is 5° to Mars's right in the evening, and Gamma Leonis is 7° above it. Mars was at opposition on March 3rd. Now it's fading and shrinking as Earth pulls ahead of it along our faster, inside-track orbit around the Sun. But at least Mars is shining higher in the evening sky now. It's highest in the south by around 10 or 11 p.m. daylight-saving time. Astro Picture of the Day: April 6, 2012 Source: After wandering about as far from the Sun on the sky as Venus can get, the brilliant evening star crossed paths with the Pleiades star cluster earlier this week. The beautiful conjunction was enjoyed by skygazers around the world. Taken on April 2, this celestial group photo captures the view from Portal, Arizona, USA. Also known as the Seven Sisters, even the brighter naked-eye Pleiades stars are seen to be much fainter than Venus. And while Venus and the sisters do look star-crossed, their spiky appearance is the diffraction pattern caused by multiple leaves in the aperture of the telephoto lens. The last similar conjunction of Venus and Pleiades occurred nearly 8 years ago. As it did then, Venus will again move on to cross paths with the disk of the Sun in June. It is the last time in our lifetime that it will do so. Unless you plan to live through the late 22nd century. --------------- What's in the Sky Tonight Archive March 1, 2013 - July 31, 2013 July 31, 2013 -Find Altair again high in the southeast after dark. To its right, by about a fist and a half at arm's length, is the dim but distinctive little constellation Delphinus, the Dolphin, jumping leftward. -Solar activity remains low. The only action on the Earthside of the sun is a minor crackling of C-class solar flares from departing sunspot AR1800. NOAA forecasters estimate a 10% chance of M-class flares and no more than a 1% chance of X-flares on July 31st. July 30, 2013 -Bright Vega shines nearly overhead these evenings, for those of us at mid-northern latitudes. Look southeast for Altair, almost as bright. Above Altair by a finger-width at arm's length is its little orange sidekick Tarazed, 3rd magnitude. -Earth is passing through a stream of debris from Comet 96P/Machholz, source of the annual Southern Delta Aquariid meteor shower. The shower's broad peak, centered on July 30th, is expected to produce a meteor every 4 or 5 minutes during the dark hours before local sunrise. Southern hemisphere observers are favored. -On July 24th, about an hour after sunset, Gerardo Connon of Rio Grande city in Tierra del Fuego, Argentina, walked outside and witnessed a rare display of nacreous clouds. The colorful apparition was as bright as the street lights in the city. These clouds, also known as "mother of pearl clouds," form in the stratosphere far above the usual realm of weather. They are seldom seen, but when they are, the reports usually come from high-northern parts of our planet. This apparition over Tierra del Fuego was unusual indeed. Atmospheric optics expert Les Cowley explains the special conditions required to create such a cloud: "Take an unusually cold lower stratosphere (15-25km high), use some gravity waves generated by high winds and storms in the troposphere to stir in some water vapour, and - voilà! You get these clouds made of tiny ice crystals shining after sunset with unforgettably bright iridescent colors."  July 29, 2013 -Last-quarter Moon (exact at 1:43 p.m. EDT). The Moon rises around midnight tonight, shining below the stars of Aries. As it climbs higher through the morning hours, look well to its lower left for the Pleiades. - A pair of CMEs launched into space on July 26th by erupting solar filaments will apparently miss Earth. The odds of a geomagnetic storm this weekend are low. July 28, 2013 -Starry Scorpius is sometimes called "the Orion of Summer" for its brightness and its prominent red supergiant (Antares in the case of Scorpius, Betelgeuse for Orion). But Scorpius is a lot lower in the sky for those of us at mid-northern latitudes. This means it has only one really good evening month: July. Catch Scorpius due south just after dark now, before it starts to tilt lower toward the southwest. -Jupiter is climbing higher above faint Mars low in the dawn. What morning can you first pick up Mercury? -On Saturday, July 27th, the Russian Space Agency launched a Progress supply ship to the International Space Station. The Progress quickly caught up with the ISS and docked to the outpost, delivering food, fuel, and the last-minute addition of a repair kit for a U.S. spacesuit that malfunctioned during a spacewalk last week. Shortly before docking, Monika Landy-Gyebnar saw the two spaceships fly over her home in Veszprem, Hungary: "The ISS appeared in the NW sky, glowing brightly," says Landy-Gyebnar. "About 10 seconds later I noticed a very faint dot of light following it - the Progress!" "At the middle of its route across the sky, the Progress spacecraft produced a very bright flare, even brighter than ISS," she continues. "It was short, but very spectacular. At maximum, the flare's astronomical magntitude was about -5, while the ISS was only -2.5. Other observers from Hungary saw it, too." (The flare was caused by sunlight glinting from a flat surface on the spacecraft.) "As the spaceships flew on towards the NE horizon, Progress became less and less bright and soon it faded into the sky background," she concludes. "The ISS remained bright until it set. Then I packed my gear and came home to watch the docking on NASA TV." -Spaceweather can tell you when fly bys will happen in your area through here: http://spaceweather.com/flybys/   July 27, 2013 -During the late hours of July 26th, two filaments of magnetism erupted on the sun. The first to blow was this loop on the sun's southwestern limb. A second filament connecting sunspots AR1800 and AR1805 erupted shortly thereafter. The explosions hurled coronal mass ejections (CMEs) into space. One of them (the one propelled by the filament connecting AR1800 and AR1805) might be heading in the general direction of Earth. An analysis the CME's trajectory is in progress as more imagery becomes available. -The students of Earth to Sky Calculus have recovered the petunias they sent to the stratosphere last Friday. The flowers left Earth July 19th onboard a helium research balloon, ascended to 110,570 feet, then parachuted back to Earth on the same day. The below four screenshots show the following scenarios: (1) The flowers were pink and alert when they left Earth. (2) An hour later, in the stratosphere, the flowers appear limp and wilted, but they were not. Actually, the flowers were frozen. The petals were bent downward by onrushing wind during the ascent, and they froze in place as the petunias passed through the tropopause where the temperature was -63 C. (3) You can see that the flowers were frozen stiff because when the balloon exploded, they did not move at all. (4) Finally, as the payload parachuted back to Earth the flowers thawed and turned deep purple.  July 26, 2013 -The Delta Aquariid meteor shower should be in its broad maximum all week. This and other weak, long-lasting July showers with radiants in the southern sky increase the chance that any meteor you see will be flying out of the south. -Mercury, Mars, and Jupiter shine low in the east-northeast during dawn. Jupiter is the highest and brightest (magnitude –1.9). Look for faint Mars (magnitude +1.6) a little to Jupiter's lower left. Look below them, and perhaps a bit left, for Mercury, which brightens from magnitude +1 to 0 this week. Best time: about 60 to 40 minutes before your local sunrise. Binoculars may help with the fainter two planets, especially through summer haze. July 25, 2013 -The waning gibbous Moon rises due east late this evening. If you have a distant, flat eastern horizon, mark the spot. The Great Square of Pegasus stands on one corner well to the rising Moon's upper left. -Solar Cycle 24 is shaping up to be the weakest solar cycle in more than 50 years. In 2009, a panel of forecasters led by NOAA and NASA predicted a below-average peak. Now that Solar Max has arrived, however, it is even weaker than they expected. It may be premature to declare Solar Cycle 24 underwhelming. Solar physicist Dean Pesnell of the Goddard Space Flight Center thinks Solar Cycle 24 is double peaked - and the second peak is yet to come. Also, weak solar cycles have been known to produce very strong flares. The strongest solar storm in recorded history, the Carrington Event of 1859, occurred during a relatively weak solar cycle like this one.  July 24, 2013 -The two brightest stars of summer evenings are Arcturus in the west now and Vega nearly overhead. They're 37 and 25 light-years away, respectively. -Mars and Jupiter are low in the east-northeast during early dawn. Jupiter is by far the brightest at magnitude –1.9. Binoculars help with finding Mars, magnitude +1.6, right close by. Jupiter and Mars passed just 3/4° from each other on the morning of July 22nd. July 23, 2013 -Look northwest after dark for the Big Dipper, hanging diagonally. Its handle is on the upper left. Follow the curve of the handle on around leftward, for a little more than a Dipper-length, to land on bright Arcturus in the west. -Solar activity has shifted from low to very low. None of the sunspots on the Earthside of the sun are actively flaring. NOAA forecasters expect this situation to continue for the next 24 hours. They estimate a slim 10% chance of M-class flares and no more than a 1% chance of X-flares on July 23rd. July 22, 2013 - Twinkly Regulus is now 1¼° below Venus at dusk. -Full Moon (exact at 2:16 p.m. EDT). The Moon travels across the sky tonight in western Capricornus.  July 21, 2013 -As twilight fades away, spot Venus low in the west-northwest. Look 1¼° to its lower left for much fainter Regulus. Bring binoculars. -Venus (magnitude –3.9) shines brightly low in the west-northwest during evening twilight. In a telescope it's still small (12 arcseconds) and gibbous (85% sunlit). -Solar activity is low. The biggest sunspot on the Earthside of the sun, AR1783, has been quiet for days even though it has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. NOAA forecasters estimate a slim 10% chance that AR1783 will break the quiet with an M-flare on July 21st. July 20, 2013 -Look upper left of the Moon after dusk, by roughly three fists at arm's length, for Altair, the bright eye of Aquila the Eagle. A little less far to the Moon's right is Antares, the fiery heart of Scorpius. -Earth's "noctilucent daisy" is glowing brighter than ever. Seeded by meteor smoke, noctilucent clouds are surrounding the north pole in a luminous circle visible from ground and space alike. Tadas Janušonis photographed this display on July 18th from Vabalninkas in the Birzai district of Lithuania:  July 19, 2013 -Telescope users looking at the gibbous Moon from most of North America tonight can watch the Moon's invisible dark limb creep up to and occult the 4.4-magnitude star Xi Ophiuchi. Only Florida and the West miss out. -Some times of the star's disappearance: in western Massachusetts, 12:38 a.m. EDT; Atlanta, 12:32 a.m. EDT; Chicago, 11:10 p.m. CDT; Winnipeg, 10:50 p.m. CDT; Kansas City, 11:00 p.m. CDT; Austin, 11:07 p.m. CDT; Denver, 9:39 p.m. MDT. Start watching early. -Opening up like a zipper almost a million kilometers long, a vast coronal hole has appeared in the sun's northern hemisphere. Coronal holes are places in the sun's upper atmosphere where the magnetic field opens up and allows solar wind to escape. A broad stream of solar wind flowing from this particular coronal hole should reach Earth on July 19-20. -In addition, NOAA forecasters say a CME could hit Earth's magnetic field late on July 18th. The combined impact of the CME and the incoming solar wind stream could cause some stormy space weather around Earth in the days ahead. NOAA forecasters estimate a 65% chance of polar geomagnetic storms on July 19-20.  July 18, 2013 -Look lower left of the gibbous Moon this evening for the red supergiant Antares. Also nearby are other stars of upper Scorpius. -Noctilucent clouds are our planet's highest clouds - but exactly how high are they? The textbook answer is 82-82 km, but textbooks can be wrong. Peter Rosén of Stockholm, Sweden, decided to find out for himself. "On July 4th I photographed some interesting NLCs," he explains. "After uploading them on Spaceweather, I noticed that P-M Hedén had photographed the same formations and at the same time from a location 26 km (16 miles) north of mine. I decided to make precise measurements of the same features in both pictures with respect to the stars and try to determine the exact geographical position and height of these NLCs.Some years ago I found a very useful calculator put online by Paul Schlyter to measure the position and altitude of Perseid meteors. By entering the geographical position of both observers and the respective coordinates of an object in the sky, it will compute the position and altitude of the object. In this case, I used it for NLCs." He picked four features color-coded in the figure below and measured their positions. "The height of these NLCs ranged from 75.1 km (blue dot) to 78.6 km (red dot)," he says. "These results seem to be a little bit lower than the value of 83 km that is often referenced." The calculator is found here: http://stjarnhimlen.se/calc/metnlcalt_en.html  July 17, 2013 -The Moon stands in central Libra this evening, about midway (for the longitudes of the Americas) between Saturn to its right and the stars of upper Scorpius to its left. -Venus (magnitude –3.9) shines brightly low in the west-northwest in evening twilight. In a telescope it's still small (12 arcseconds) and gibbous (87% sunlit). But for the rest of the year, watch it grow in size and wane in phase until becoming a long, ultra-thin crescent. July 16, 2013 -This evening the Moon shines below Saturn, with Spica now off to their lower right. -Aisle or window? The next time you're making that decision at the airport, consider the following snapshot. "I was expecting auroras when I boarded Air Canada flight 854 from Vancouver to Heathrow on the evening of July 14th - and I was not disappointed," reports photographer Yuichi Takasaka. "Above the James Bay in the northern Manitoba, the lights grew so bright that I could see them through the twilight. Note the colors reflected from the wing of the plane, these were the strongest auroras I've seen from an airliner ever!" A 0.25 second exposure yielded this image: -According to NOAA forecasters the odds of a polar geomagnetic storm on July 16th are 20%, increasing to 50% on July 18th when a solar wind stream is expected to hit Earth's magnetic field. Add to that the near-certainty of high-latitude noctilucent clouds and ... pick the window seat.  July 15, 2013 -First-quarter Moon (exact at 11:18 p.m. EDT). Look quite close to the Moon for Spica. Saturn glows off to their upper left. Think photo opportunity. -The Moon occults (hides) Spica for skywatchers in Hawaii and parts of Central and South America. For Timetables: http://www.lunar-occultations.com/io...0716zc1925.htm  July 14, 2013 -Do you live too far north to see Alpha Centauri? The nearest star for northerners is Barnard's Star, a red dwarf 6.0 light-years away in northern Ophiuchus. At magnitude 9.6 it's fairly easy in most telescopes. -Mars and Jupiter are low in the east-northeast during early dawn. Jupiter is far and away the brightest at magnitude –1.9. Look just upper right of it for Mars, magnitude +1.6. Binoculars help. Jupiter is drawing closer to Mars daily. They'll pass just 3/4° apart on the morning of July 22nd. July 13, 2013 -Summery Scorpius struts in the south right after dark. Now is the time (before the Moon grows bright) to explore its Milky-Way-rich southern part, full of bright deep-sky objects. The northern part of Scorpius includes orange Antares and, to Antares's right, Delta Scorpii, a star that 13 years ago doubled in brightness and still rivals Antares for attention. -Saturn is near eastern quadrature during July and August (90° east of the Sun), so this is when its globe casts the widest shadow onto the rings behind, as seen from Earth's viewpoint. That's the black band on the rings just off the globe at lower right of center (celestial northeast). Meanwhile, the rings are now casting an almost equally prominent shadow onto the globe. That's the black rim above the rings (south here is up). Both add to Saturn's 3-D appearance in a telescope. The gray band on the globe just inside the rings is the semitransparent C Ring, the sparse "Crepe Ring," with no shadow currently behind it to confuse its appearance. Damian Peach shot this extraordinarily fine image through excellent seeing conditions on July 8th.  July 12, 2013 -The crescent Moon, faint Regulus, and bright Venus form a curving line low in the western twilight, as shown below. -Not all colorful lights in the sky are the aurora borealis. The green light in the picture below is called "airglow." Airglow is a luminous bubble that surounds our entire planet, fringing the top of the atmosphere with aurora-like color. Although airglow resembles the aurora borealis, its underlying physics is different. Airglow is caused by an assortment of chemical reactions in the upper atmosphere driven mainly by solar ultraviolet radiation; auroras, on the other hand, are ignited by gusts of solar wind. Green airglow is best photographed from extremely dark sites on nights when the Moon is new or below the horizon. It often shows up in long exposures of the Milky Way: more airglow.Astrophotographer Kenneth Edwards discovered this for himself on July 4th when he was taking a long exposure of the Milky Way over Big Bend National Park, Texas:   July 11, 2013 -As twilight fades, spot the crescent Moon low in the west. Venus is roughly 1½ fist-widths at arm's length to its right (for North America). As dusk deepens, watch for Regulus and Gamma (γ) Leonis coming into view above them, as shown below. -Despite its unstable magnetic field, big sunspot AR1785 has resisted exploding. Even so, it's putting on a good show. Pretty sunsets could give way to actual solar flares if the magnetic field of AR1785 finally erupts. For the 5th day in a row, flare probabilities remain high: NOAA forecasters estimate a 55% chance of M-flares and a 10% chance of X-flares. Pete Lawrence of Selsey UK photographed the active region as a dark-mark in the sunset on July 9th:  July 10, 2013 -Soon after sunset while the sky is still bright, watch for the thin crescent Moon coming into view just above the west horizon, to the lower left of Venus. Binoculars help. -A minor CME hit Earth's magnetic field on July 9th at approximately 20:30 UT. The impact was weak, and at first had little effect, but now a geomagnetic storm is in progress as Earth passes through the wake of the CME July 9, 2013 -If you have a dark enough sky, the Milky Way forms a magnificent arch high across the eastern sky after nightfall. It runs all the way from below Cassiopeia in the north-northeast, up and across Cygnus and the Summer Triangle in the east, and down past the spout of the Sagittarius Teapot in the south. -Astrophotographer Thierry Legault is known for his razor-sharp images of spacecraft. Yesterday, for a change of pace, he photographed a razor-sharp crescent. "This image shows the tiny lunar crescent at the precise moment of the New Moon, in full daylight at 7h14min UTC on July 8 2013," says Legault. "It is the youngest possible crescent, the age of the Moon at this instant being exactly zero." "From the shooting site in Elancourt, France, the angular separation between the Moon and the Sun was only 4.4° (nine solar diameters)," he continues. "At this very small separation, the crescent is extremely thin (a few arc seconds at maximum) and, above all, it is drowned in the solar glare, the blue sky being about 400 times brighter than the crescent itself in infrared and probably more than 1000 times brighter in visible light. In order to reduce the glare, the images have been taken at near-infrared wavelengths using a pierced screen placed just in front of the telescope to block direct sunlight."  July 8, 2013 -This is the time of year when, as twilight fades to dark, the two brightest summer stars, Arcturus and Vega, shine equally close to the zenith (depending on where you are). Arcturus is the one toward the southwest; Vega is toward the east. -New Moon (exact at 3:14 a.m. on this date EDT). Colossal sunspot AR1785 is now directly facing Earth. The active region has a 'beta-gamma-delta' magnetic field that harbors energy for X-class flares, yet so far the sunspot has been mostly quiet. Could it be the calm before the storm? NOAA forecasters estimate a 55% chance of M-flares and a 10% chance of X-flares on July 8th. Solar flare alerts: text, voice. Sprawling more than 11 Earth-diameters from end to end, AR1785 is one of the biggest sunspots of the current solar cycle. Christian Viladrich of Nattages, France, used a filtered 14-inch Celestron telescope to take this picture. All those irregular blobs surrounding the primary dark core are boiling granules of plasma as small as the state of California or Texas.  July 7, 2013 -When the stars begin to come out these evenings, the Big Dipper hangs straight down from its handle high in the northwest, while the dim, elusive Little Dipper stands straight up on its handle from Polaris in the north. -When Opportunity left Earth on July 7, 2003, many observers expected the rover to survive no more than a few months on the hostile surface of Mars. Ten years later, Opportunity is still going strong and could be poised to make its biggest discoveries yet at a place named Solander Point. -Behemoth sunspot AR1785 is undergoing a metamorphasis, changing shape by the hour as it turns toward Earth. In less than 24 hours, AR1785 has stretched and lengthened by more than 40,000 km. It is now more than 11 times as wide as Earth, which makes the active region an easy target for backyard. This movie from NASA's Solar Dynamics Observatory shows the action on July 6-7:  July 6, 2013 -Two hours after sunset, after darkness is truly complete, the east-northeast horizon bisects the Great Square of Pegasus across two of its opposite corners. By midnight the whole Great Square is up in good view, balancing on its bottom corner. -Observers of noctilucent clouds often describe their appearance as "electric blue." The pale blue colors of the two phenomena are similar, but the resemblance is superficial. Lightning is hot, a genuinely electric discharge that heats the air to 30,000o C or more. The high temperature of the lightning's plasma (ionized air) gives it the same blue color as a hot O-type star. On the other hand, noctilucent clouds are cold, made of ice that crystallizes at the edge of space where the air temperature is -160o C. The tiny ice crystals in noctilucent clouds scatter blue light from the setting sun, which accounts for their lightning-like color. On July 3rd, Nature provided a color-check when a lightning storm erupted in Szubin, Poland, right in front of a noctilucent display. Marek Nikodem photographed the ensemble:   July 5, 2013 -During dawn this morning and Saturday morning, look low in the east-northeast for the waning Moon. It guides your way to Mars, Jupiter, Aldebaran, and Beta Tauri, as shown at right. Binoculars will help. -Earth is at aphelion, its farthest from the Sun for the year (just 1 part in 30 farther than at perihelion in January). July 4, 2013 -Watching the fireworks tonight? As you're waiting for them to begin, point out to people some sky sights. The two brightest stars of summer, Vega and Arcturus, are high overhead toward the east and southwest, respectively. Far below Arcturus are the planet Saturn and, to its lower right, Spica. Nearly that high in the southeast is the orange-red supergiant Antares, amid fainter stars of upper Scorpius. -The July waning crescent Moon passes landmarks of Taurus. The visibility of faint objects in twilight is exaggerated here; binoculars help. The blue 10° scale is about the width of your fist at arm's length.  July 3, 2013 -A twilight challenge: As twilight fades, spot Venus low in the west-northwest. As darkness deepens, can you make out stars of the Beehive Cluster within about ½° below it? Good luck — the brightest of them are 6th magnitude, about 10,000 times fainter than Venus! -A much easier challenge: Look ½° above Saturn soon after dark for the 4.2-magnitude star Kappa Virginis.  July 2, 2013 -The Big Dipper, high in the northwest after dark, is turning around to "scoop up water" through the nights of summer and early fall. -The "noctilucent daisy" continues to expand and intensify as summer unfolds. Observers in central-to-northern Europe are reporting vivid, nightly displays of NLCs. Just hours ago, Alan Tough photographed these over Lossiemouth, Moray, Scotland. "This was another spectacular display of noctilucent clouds," says Tough. "I arrived in Lossiemouth in time to see the Moon rising and managed to capture its glitter path on the River Lossie."  July 1, 2013 -If you have a dark enough sky, the Milky Way now forms a magnificent arch high across the whole eastern sky after nightfall is complete. It runs all the way from below Cassiopeia low in the north-northeast, up and across Cygnus and the Summer Triangle in the east, and down past the spout of the Sagittarius Teapot in the south-southeast. June 30, 2013 -Vega is the brightest star high in the east. Right next to Vega lies one of the best-known multiple stars in the sky: 4th-magnitude Epsilon (ε) Lyrae, the Double-Double. It forms one corner of a roughly equilateral triangle with Vega and Zeta (ζ) Lyrae. The triangle is less than 2° on a side. A 4-inch telescope at 100× or more should resolve each of Epsilon's two wide components into a tight pair. Zeta Lyrae is also a double star for binoculars; much tougher, but easily split with a telescope. -As the current spate of geomagnetic storming subsides, more storms could be in the offing. A coronal mass ejection (CME), pictured below, is expected to deliver a glancing blow to Earth's magnetic field late on June 30th or early on July 31st. -The cloud was propelled in our direction during the early hours of June 28th when magnetic filaments around sunspot AR1777 erupted. The explosion registered approximately C4 on the Richter Scale of Solar Flares. Because the CME is not heading squarely toward Earth, there is still a chance that it will miss. For understanding the RIchter Scale of Solar Flares: http://www.spaceweather.com/glossary...8s4qc6tuni8p14  June 29, 2013 -This is the time of year when, after dark, the dim Little Dipper floats straight upward from Polaris (the end of its handle) — like a helium balloon on a string escaped from some summer evening party. -Mercury is lost in the glare of the Sun. A strong (Kp=7) geomagnetic storm is in progress on June 28-29 as Earth passes through a region of south-pointing magnetism in the solar wind. The storm has sparked Northern Lights photographed in the USA as far south as Kansas. Christian Begeman sends this picture from a farm outside Hartford, South Dakota: "A clear sky allowed me to the Northern Lights dancing in southeast South Dakota around the midnight hour tonight," says Begeman. "It was quite the show." High-latitude sky watchers should remain alert for auroras in the hours ahead. Solar wind conditions continue to favor geomagnetic activity.  June 28, 2013 -Southern hemisphere sunspots AR1777 and AR1778 erupted in quick succession during the early hours of June 28th, producing a pair of C-class solar flares and at least one CME. An initial analysis of coronagraph images suggests that the CME could deliver a glancing blow to Earth's magnetic field over the weekend. -The Big Dipper, still high in the northwest, is moving a little lower now and starting to dip around toward the right. Follow the curve of its tail a little more than a Dipper-length left to bright Arcturus high in the southwest. June 27, 2013 -Venus (magnitude –3.8) is gaining altitude very gradually, low in the west-northwest in evening twilight. Use binoculars to pick up Pollux and Castor off to its upper right or right. -Mars and Jupiter remain hidden in the glare of the Sun. -Every day, NASA's AIM spacecraft maps the distribution of noctilucent clouds (NLCs) around Earth's north pole. The results are displayed on spaceweather.com in the form of the "daily daisy." On June 20th, pilot Brian Whittaker flew past a vivid display of NLCs over the North Atlantic Ocean and he decided to compare his own view to that of AIM. -"Once again, AIM's daily daisy-wheel allowed me to see where the northern horizon noctilucent clouds truly were!" says Whittaker. "This display reached a maximum height of about 10 degrees as seen from 37,000 feet at 50N latitude. It was my 4th and best sighting of 2013 so far." -2013 is shaping up to be a good year for NLCs. The clouds surprised researchers by appearing early this year, and many bright displays have already been recorded. Once confined to the Arctic, NLCs have been sighted in recent years as far south as Utah, Colorado, and Nebraska. They might spread even farther south in 2013. -Observing tips: Look west 30 to 60 minutes after sunset when the sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you've probably spotted a noctilucent cloud. -Here are the results:   June 26, 2013 -Now that it's summer, the Summer Triangle stands high in full glory after dusk. Its top star is bright Vega high in the east. Deneb is the brightest star to Vega's lower left. Farther to Vega's lower right is Altair. The Summer Triangle is big: 35° long. Where the sky is dark, you can see that the Milky Way runs through it. -Solar activity is low. None of the sunspots on the Earthside of the sun has the kind of complex magnetic field that harbors energy for strong flares. NOAA forecasters put the odds of an M-class solar flare at 20% on June 26th, waning to 10% on June 27th. June 25, 2013 -10,000 near-Earth asteroids and comets have now been discovered. The 10,000th object, asteroid 2013 MZ5, was detected on June 18th by the Pan-STARRS-1 telescope in Maui. Sobering estimate: NASA says there may be 10 times this number yet to find. -During bright twilight today and tomorrow, Venus forms an almost straight line with Pollux and Castor low in the west-northwest. Bring binoculars, and look for them to Venus's right. And can you still detect Mercury below Venus? It's nearly as far below Venus (6°) as Pollux is to the right. June 24, 2013 -Look a third of the way from Arcturus to Vega for dim Corona Borealis, the semicircular Northern Crown. It has one moderately bright star, Alphecca (magnitude 2.2). Look two thirds of the way for the dim Keystone of Hercules, whose brightest star is magnitude 2.8. June 23, 2013 -This is the time of year when the two brightest stars of summer, Arcturus and Vega, are about equally high overhead shortly after dark. Arcturus is toward the southwest, Vega toward the east. -Arcturus and Vega are 37 and 25 light-years away, respectively, and represent the two commonest types of naked-eye stars: a yellow-orange K giant and a white A main-sequence star. They're 150 and 50 times brighter than the Sun — which, combined with their nearness, is why they dominate the evening sky. -Mercury is becoming a real challenge, rapidly fading and dropping below Venus very low in bright twilight. Bring binoculars. What's the last day you can keep it in view? June 22, 2013 -The largest full Moon of 2013 rises around sunset and shines all night. Tomorrow night it's almost as full and almost as large (for the longitudes of the Americas, since the Moon is exactly full at 7:32 a.m. Sunday morning EDT.) On both nights, though, this "supermoon" is only a trace larger than an average Moon: 7% wider. -On June 21st at 03:16 UT, the sun itself marked the solstice with an M2-class solar flare from sunspot AR1777. NASA's Solar Dynamics Observatory photographed the extreme ultraviolet flash and a plume of material flying out of the blast site. As sunspots go, AR1777 is neither large nor apparently menacing, yet it has been crackling with flares for days. Before it rotated over the sun's eastern limb on June 20th, it unleashed a series of farside flares and CMEs. Today's explosion was not Earth directed, but future explosions could be as the sun's rotation continues to turn AR1777 toward our planet. NOAA forecasters estimate a 30% chance of M-flares and a 5% chance of X-flares during the next 24 hours.  June 21, 2013 -As Mercury fades and descends below Venus day by day, how long can you keep it in view? -After dark, look for fire-colored Antares to the lower right of the bright Moon.  June 20, 2013 -Look lower left of the Moon at dusk, by almost two fists at arm's lengths, for orange-red Antares. Between them is the three-star row of the Head of Scorpius, nearly vertical. -This is Midsummer's Night, the shortest night of the year in the Northern Hemisphere. The solstice is at 1:04 a.m. on the 21st EDT; 10:04 p.m. on the 20th PDT.  June 19, 2013 -Dim little Mercury is closest to bright Venus low in twilight this evening. Look for it 2° to Venus's lower left. -Saturn glows to the upper right of the waxing gibbous Moon as night falls.  June 18, 2013 -The magnetic field of sunspot AR1775 is growing more complex, increasing the chance of an eruption. NOAA forecasters estimate a 20% chance of M-class solar flares on June 19th. -During the early hours of June 18th, a long-duration flare from this active region hurled a coronal mass ejection (CME) over the sun's eastern limb. However, none of the rocky planets (Mercury, Venus, Earth, Mars) were in the line of fire. -The Moon now shines just below the line between Spica and Saturn. June 17, 2013 -The Moon this evening forms the end of a curving line with Spica and Saturn, counting to the Moon's left. Look below the Moon for the four-star figure of Corvus. -Watch the gibbous Moon pass Spica and Saturn. The Moons here are plotted for the middle of North America. They are three times actual size. June 16, 2013 -First-quarter Moon (exact at 1:24 p.m. EDT). The Moon shines under the dim head of Virgo. -Venus (magnitude – 3.8) is gaining altitude very gradually, low in evening twilight. Look for it in the west-northwest. Mercury has closed to just 2° or 3° from Venus, but Mercury is fading fast: from magnitude +0.6 on the 15th to +1.6 on the 22nd. Look for it to Venus's upper left (for mid-northern observers) early in the week, directly left around June 16th and 17th, and below Venus by the 20th. June 15, 2013 -Mercury is drawing closer to Venus as it fades in the twilight, as shown below. They're 3.3° apart now and will be 2° from each other at their closest on the 19th.  June 14, 2013 -The waxing crescent Moon hangs to the lower left of Regulus and the Sickle of Leo this evening. -If you've been looking for Jupiter, stop. The glare could hurt your eyes. Jupiter is approaching the sun for an extremely tight conjunction. Today they are only 3.5 degrees apart. On June 19th, Jupiter will pass directly behind the solar disk, less than a quarter of a degree from disk center. It's a rare total eclipse of Jupiter by the sun. Because of the glare, the event is invisible to human eyes. Coronagraphs, however, block the glare and monitor Jupiter's approach.  June 13, 2013 -Look above the Moon after nightfall to spot Regulus and the Sickle of Leo. -Saturn (magnitude +0.4, in Libra) glows in the south during evening, with Spica 12° to its right. Look almost as far to Saturn's left or lower left for Alpha Librae. -In a telescope, Saturn's rings are tilted 17° from our line of sight. -The sunspot number may be low, but the sun is far from blank. Amateur astronomers monitoring the sun report a large number of magnetic filaments snaking across the solar disk. Sergio Castillo captured more than half a dozen in this picture he sends from his backyard observatory in Inglewood, California:  June 12, 2013 -The interesting binocular field around Antares holds the dim glow of the globular cluster M4, as many skywatchers well know. But do you also know about Rho Ophiuchi, the fine binocular triple star in the same field? It's the top of a loop of five stars including Antares. -Mercury and Venus remain in twilight view low in the west-northwest, but Mercury is fading: from magnitude +0.2 to +0.8 from June 7th to 14th. Mercury is upper left of much brighter Venus, magnitude –3.8. Their separation closes from 5° to 3.6° during this time. Above them shine fainter Castor and Pollux. June 11, 2013 -The waxing Moon after sunset now forms a wide arc with Castor, Pollux, and low Procyon, as shown at right. Venus and Mercury are not far from the center of the arc's curve. -Early Wednesday morning, the faint asteroid 332 Siri will will occult (hide) a 6.4-magnitude star east of Antares for up to 4 seconds as seen along a track from Oklahoma across northwest Texas, southern New Mexico, and southern Arizona. The star is an unusually bright one to be occulted by an asteroid, but the event happens low in the southwestern sky. Details: http://www.asteroidoccultation.com/2..._332_29849.htm  June 10, 2013 -The thin crescent Moon low in twilight now forms a triangle with Venus and Mercury, as shown at right. Look above the triangle for the Pollux-and-Castor pair. -NOAA forecasters have downgraded the chance of polar geomagnetic storms today to 25%. A CME expected to deliver a glancing blow to Earth's magnetic field on June 9th did not arrive on time and might have missed our planet altogether. -Sky watchers in North America might see an outburst of meteors during the early hours of June 11th when Earth passes through a stream of cometary debris last seen in 1930. Forecasters Peter Jenniskens (SETI Institute) and Esko Lyytinen (Helsinki, Finland) predict the return of the gamma Delphinid meteor shower this Tuesday morning around 08:30 UT (04:30 am EDT). The shower is expected to last no more than about 30 minutes with an unknown number of bright, fast meteors. Bill Cooke of NASA's Meteoroid Environment Office will chat about the shower starting tonight at 11 PM EDT. Link: http://www.nasa.gov/connect/chat/gamma_chat.html June 9, 2013 -After sunset, look for the young crescent Moon about 6° to 8° below Venus very low in the west-northwest (at the times of twilight in North America). Binoculars will help. -NOAA estimates a 60% chance of polar geomagnetic storms on June 9th when a CME is expected to deliver a glancing blow to Earth's magnetic field. High-latitude sky watchers should be alert for auroras. -High latitude sky watchers should be alert for NLCs in the evenings ahead. In recent years they have been sighted as far south as Utah, Colorado, and Nebraska. Observing tips: Look west 30 to 60 minutes after sunset when the sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you've probably spotted a noctilucent cloud.  June 8, 2013 -After dark, look southeast for orange-red Antares. It's one of the two great red supergiants of the naked-eye sky; the other is Betelgeuse in winter. Around and to the upper right of Antares are other, white stars of upper Scorpius. -This morning marks day 2 of the peak of the Arietids. The best way to observe the Arietids is via radar. Listen to their echoes on Space Weather Radio. http://spaceweatherradio.com/ -New Moon (exact at 3:14 a.m. on this date EDT). June 7, 2013 -This week, Earth is passing through a stream of debris from asteroid Icarus, source of the annual Arietid meteor shower. The strange thing about this shower is that it occurs mainly during daylight hours. At its peak on June 7-8, as many as 60 Arietids per hour will streak invisibly across the blue sky after sunrise. The best way to observe the Arietids is via radar. Listen to their echoes on Space Weather Radio. http://spaceweatherradio.com/ -Mercury in the twilight has reached its farthest distance above Venus, 5°. See the scene below. They're as far apart as fainter Pollux and Castor above them, which come into view as twilight dims. 5° is about three finger-widths at arm's length.  June 6, 2013 -With June well under way, the Big Dipper has swung around to hang down by its handle high in the northwest after dark. The middle star of its handle is Mizar, with tiny little Alcor right next to it. On which side of Mizar should you look for Alcor? As always, on the side exactly toward Vega! Which is now shining in the east. June 5, 2013 -Vega is the brightest star in the east these evenings. The main part of its little constellation, Lyra, dangles from it to its lower right. -Jupiter is now all but out of view and only Venus and Mercury remain in the evening planet dance. However, Pollux and Castor will soon be joining them. June 4, 2013 -Above the Big Dipper's high handle is north-central Bootes, home to double stars, three spindle galaxies, and the Kangaroo asterism. -By June 5th the line of Venus, Mercury and Jupiter is 13° long with Jupiter falling far away. June 3, 2013 -"Cassiopeia" usually means "Cold!". Late fall and winter are when this landmark constellation is high overhead (seen from mid-northern latitudes), but even on hot June evenings it's lurking low. After dark, look for it down near the north horizon. It's a wide, upright W. The farther north you are the higher it'll appear. But even as far south as San Diego and Atlanta it's completely above the horizon. -Mercury, Venus, and Jupiter are still visible in the afterglow of sunset, forming a straight line pointing downward just above the west-northwest horizon as shown at the top of this page. Venus is the brightest. Jupiter, the bottom one, becomes harder to see each day and is gone by the end of the week. Mercury on top is having its best evening appearance of 2013. June 2, 2013 -The best time to view Venus in a telescope is in late afternoon well before sunset, when it's still at a high altitude in relatively steady air. Mercury and Jupiter are in the same vicinity, but they're tougher catches in broad daylight. -Mercury, Venus, and Jupiter are still visible in the afterglow of sunset, forming a straight line pointing downward just above the west-northwest horizon as shown at the top of this page. Venus is the brightest. Jupiter, the bottom one, becomes harder to see each day and is gone by the end of the week. Mercury on top is having its best evening appearance of 2013. June 1, 2013 -Vega, shining brightly in the east-northeast, it currently the top star of the huge Summer Triangle. Look to Vega's lower left, by two or three fists at arm's length, for Deneb. The third star of the Summer Triangle is Altair, considerably farther to Vega's lower right. Altair is barely rising in the east as dusk fades away this week. How early in the evening can you spot it? -At this time of year, right as the stars come out, the bright constellation Cassiopeia is directly underneath Polaris.  May 31, 2013 -Mercury, Venus, and Jupiter have stretched out into a nice straight line 7° long. Look low in the northwest after sunset. The line will continue to lengthen day by day, as Jupiter descends to the horizon and Mercury pulls a bit higher above Venus. -Last-quarter Moon (exact at 2:58 p.m. EDT). May 30, 2013 -Vega is the brightest star in the east-northeast these evenings. The main part of its little constellation, Lyra, hangs from it to its lower right. -The bright planets in these scenes are plain to the naked eye, but the fainter stars may be hard or impossible to see in bright twilight. The scenes are about three fist-widths at arm's length wide. They're drawn for the middle of North America but will be good enough throughout the world's mid-northern latitudes. Today the planet trio forms a line.  May 29, 2013 -Here it is not even June yet, and the Big Dipper after dusk is already turning around to hang down by its handle. Look for it high in the northwest. -The planet dance is on its way to form a line tonight. Venus and Jupiter are vertically aligned depending on your point of view. May 28, 2013 -Jupiter and Venus are now at their closest together, 1° apart low in the west-northwest after sunset. Mercury is above them. -Mercury, Venus, and Jupiter are bunched together low in the afterglow of sunset, forming a new configuration each evening. They're magnitudes –1, –4, and –2, respectively. From the 24th through 29th the three form a "trio," fitting in a circle 5° in diameter. They're bunched most tightly, fitting in a 2½° circle, on the evening of the 26th.  May 27, 2013 -This is the time of year when Spica, the brightest star of Virgo, shines due south just after dark. It's far to the lower right of high, bright Arcturus. Its name means "ear of wheat," and the Virgo stick figure is holding it in her hand without paying much attention. To Spica's lower right (by about a fist and a half at arm's length) is the four-star pattern of Corvus the Crow, eyeing it greedily. This year Corvus has Saturn to try to steal too. Saturn is glowing to Spica's left, noticeably brighter. -Mercury, Venus, and Jupiter are bunched together low in the afterglow of sunset, forming a new configuration each evening. They're magnitudes –1, –4, and –2, respectively. From the 24th through 29th the three form a "trio," fitting in a circle 5° in diameter. They're bunched most tightly, fitting in a 2½° circle, on the evening of the 26th. May 26, 2013 -Mercury, Venus, and Jupiter are bunched their tightest this evening, forming a little triangle just 2° on a side. Look in the northwest 30 or 40 minutes after sunset. Think photo opportunity. -The best time to view Venus at high power in a telescope is in late afternoon well before sunset, when it's still at a high altitude in relatively steady air. All week Mercury and Jupiter are in the same vicinity, but they're tougher catches in broad daylight. -Mercury, Venus, and Jupiter are bunched together low in the afterglow of sunset, forming a new configuration each evening. They're magnitudes –1, –4, and –2, respectively. From the 24th through 29th the three form a "trio," fitting in a circle 5° in diameter. They're bunched most tightly, fitting in a 2½° circle, on the evening of the 26th. -Mercury and Venus appear closest together, just under 1½° apart, on the 23rd and 24th. Venus and Jupiter are closest, 1° apart, on the 28th. May 25, 2013 -The Jupiter-Venus-Mercury trio continues shrinking. Above it, by contrast, the enormous Arch of Spring spans much of the western sky as twilight dims. Its highest part is the Pollux-and-Castor pair, roughly horizontal and about three finger-widths apart. Look far to the lower left of Pollux and Castor for Procyon, and farther to their lower right for Menkalinen and then bright Capella. Consult the video below for the planet dance. May 24, 2013 -Jupiter, Venus, and Mercury, low in the afterglow of sunset, are now officially a "trio": they fit within a 5° circle. The means you could just about cover them with a golf ball at arm's length, and they'll fit in the view of most binoculars. They'll stay at least this close through next Wednesday the 29th. This evening, Venus and Mercury appear their closest together. Full Moon (exact at 12:25 p.m. EDT tonight). The Moon is only two days from perigee, so it appears a tiny trace bigger than average. The dazzling Moon occults (covers) the 2nd-magnitude star Beta Scorpii this evening for much of the eastern U.S. except the Northeast. May 23, 2013 -Starting from Saturn in the south-southeast as evening grows late, follow a diagonal line of five objects toward the lower left: Saturn, fainter Alpha Librae, the glaring Moon, Delta Scorpii, and Antares. -Saturn (magnitude +0.2, in Libra) glows in the southeast during twilight, with Spica to its upper right and Arcturus twice as far to its upper left. It's highest in the south not long after dark. May 22, 2013 -Tonight the Moon shines with Saturn. Although they look close together, the Moon is only 1.3 light-seconds from Earth while Saturn is 74 light-minutes in the background.  May 21, 2013 -The star near the waxing gibbous Moon this evening is Spica in Virgo. -Venus (magnitude –3.9) is still quite low in the west-northwest in twilight, to the lower right of Jupiter. Watch as Venus and Jupiter draw together by about 1° per day. On May 17th they're still 11° apart. Their conjunction comes on the 28th, when they'll be 1° apart with Mercury right alongside. May 20, 2013 -Low in the afterglow of sunset, Jupiter has drawn to within 8° of Venus, which shines to its lower right. Can you see Mercury yet, 3° to the lower right of Venus? -These three planets about to swing through a "trio" together, as shown in the video below. They'll appear closest together in a tight little triangle, 2° on a side, next Sunday the 26th. May 19, 2013 -This is the time of year when the longest of the 88 constellations, mostly-dim Hydra, snakes level after dark all way across the sky from its head in the west (between Regulus and Procyon) to its tail-tip in the southeast (under Saturn). May 18, 2013 -Saturn (magnitude +0.2, in Libra) glows in the southeast in twilight. Spica is to its upper right, and Arcturus is twice as far to its upper left. -Saturn is highest in the south around 11 p.m. or so. In a telescope, its rings are nicely tilted 18° from our line of sight. -Yes, it is a polar hexagon! The Voyager 2 spacecraft first revealed its shape, but now that Saturn's north polar region has come into Saturnian summer sunlight, amateur Damian Peach recorded the shape of the Hexagon as clear as day from Earth in this image taken on April 21, 2013, and re-projected as this pole-on view.   May 17, 2013 -By about 10 p.m. daylight saving time this week (depending on where you live), summery Antares becomes visible very low in the southeast with other stars of Scorpius around it. -Find Antares about three fists at arm's length to the lower left of Saturn. Along the way you'll pass fainter Alpha Librae (not far from Saturn), and not-so-faint Delta Scorpii (relatively close to Antares).  May 16, 2013 -Just after nightfall at this time of year, Vega rising in the northeast is at the same altitude as Capella descending in the west. How accurately can you time this event? The time depends on your location, and wherever you are, it happens four minutes earlier each day May 15, 2013 - Chi (χ) Cygni, one of the brightest red long-period variable stars, is having an unusually bright maximum. For the last two weeks it's been about magnitude 3.8, very plain to the naked eye. Look for it adding to the bottom part of the shaft of the Northern Cross, between Eta (η) and Beta (β) Cygni. Cygnus is reasonably well up in the east by about 11 p.m., with the Northern Cross lying on its side.   May 14, 2013 -Arcturus, high in the southeast, is sometimes called the "Spring Star," and Vega low in the northeast is called the "Summer Star." Look a third of the way from Arcturus down to Vega for the dim semicircle of Corona Borealis, the Northern Crown, with its one brightish star Alphecca. Look two thirds of the way for the dim Keystone of Hercules. May 13, 2013 -Three zero-magnitude stars shine after dark in May: Arcturus high in the southeast, Vega much lower in the northeast, and Capella in the northwest. They appear so bright because each is at least 60 times as luminous as the Sun, and they are all relatively nearby: 37, 25, and 42 light-years from us, respectively. May 12, 2013 -Jupiter and the 3-day-old Moon shine in the west at dusk, as shown below. Look for Betelgeuse still twinkling to their left. -Saturn (magnitude +0.2, in Libra) is two weeks past opposition and climbing higher in the evening sky. It glows low in the southeast after nightfall (lower left of Spica and farther lower right of Arcturus), and is highest in the south around midnight. Stay up late with your scope.  May 11, 2013 -The beautiful 2-day-old crescent Moon hangs below Jupiter in the western evening twilight, as shown above. Look below the Moon for twinkly Aldebaran on its way out for the year. -Venus (magnitude –3.9) is beginning an evening apparition that will continue the rest of this year. Can you pick it up yet? Look about 20 minutes after sunset just above the west-northwest horizon (well to the lower right of Jupiter as seen from mid-northern latitudes). -And watch as Venus and Jupiter draw together this month, by 1° per day. They're 18° apart on May 10th and 11° on the 17th. Their conjunction comes on the 28th, when they'll be a close, 1° couple — with Mercury right alongside. May 10, 2013 -Young Moon challenge. Have you ever seen a crescent Moon as young as about 24 hours? Not many people have, and in North America, now's your chance. Look just above the west-northwest horizon starting 15 minutes after sunset. The Moon is way down there close to Venus. Binoculars help, then try with your naked eyes. -Note the time, then determine how long this is since new Moon occurred yesterday at 8:28 p.m. Eastern Daylight Time. The difference tells the Moon's current age. Does it break your personal record? -Starting soon after sunset on Friday the 10th, use binoculars to look for the hairline Moon low near Venus. The Moon is much easier by Saturday the 11th. -The visibility of the fainter objects in bright twilight is exaggerated here. These scenes are drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. For clarity, the Moon is shown three times actual size. May 9, 2013 -The famous binary star Gamma Virginis (Porrima) has widened to a separation of 2 arcseconds this spring, after being too close for amateur telescopes to resolve for much of the previous decade. It's the 3rd-magnitude star 15° upper right of Spica these evenings. -New Moon, exact at 8:28 p.m. Eastern Daylight Time. May 8, 2013 -SIf you're up around midnight, go out and look southeast for a preview of summery Scorpius rearing up into good view, sporting fiery Antares as its heart. -The annular eclipse Australia will get to experience occurs tomorrow, May 10 [due to timezone differences]. May 7, 2013 -Summer is more than six weeks away, but the Summer Triangle is making its appearance in the east one star after another. The first in view is Vega. It's already visible low in the northeast as twilight fades. -Next up is Deneb, lower left of Vega by two or three fists at arm's length. Deneb takes about an hour to appear after Vega does, depending on your latitude. -The third is Altair, which doesn't show up far to their lower right until around midnight. -Australia will be treated to an annular eclipse later in the week on May 10, as well as parts of Papua New Guinea.  May 6, 2013 -The brightest star high in the southeast after nightfall is Arcturus. Far to its lower right are Spica and, lower, Saturn. To the right of these two, look for the quadrilateral of Corvus, the Crow. -Jupiter (magnitude –2.0, in Taurus) is the first "star" to come out in the west after sunset, a little lower every day. It descends in the evening and sets around 10 or 11 p.m. Above Jupiter is El Nath (Beta Tauri). Much farther to Jupiter's upper right is bright Capella. -In a telescope, Jupiter has shrunk to a disappointing 33 arcseconds wide, about as small as it ever gets. May 5, 2013 -The western Arch of Spring is on fine display in late twilight. Its top consists of Pollux and Castor high in the west. They're lined up roughly horizontally and are about three finger-widths at arm's length apart. Look far to their lower left for Procyon, and farther to their lower right for brighter Capella. -Far below the arch this spring, two more points make it a pentagon. These are bright Jupiter and, about two fists to Jupiter's left, Betelgeuse. May 4, 2013 -The three brightest stars in the May dusk are all zero magnitude: Capella in the northwest, Vega lower in the northeast, and Arcturus high in the east. (Jupiter, far lower left of Capella, is brighter but doesn't count.) -The Eta Aquariid meteor shower, usually the year's best for the Southern Hemisphere, should be strongest just before dawn. Fewer of its meteors can be seen from the latitudes of the southern U.S., and few or none from the northern U.S. and Europe. May 3, 2013 -As soon as it's fully dark, look for the Big Dipper very high in the north-northeast. It's upside down, with its handle to the right and its bowl to the left. It's "dumping water" onto the much dimmer Little Dipper down below. May 2, 2013 -Last-quarter Moon. The Moon, between dim Capricornus and Aquarius, rises around the middle of the night (far below Altair). By daybreak Friday morning it's high in the south. May 1, 2013 -Jupiter (magnitude –2.0, in Taurus) is the first "star" to come out in the west after sunset, a little lower every day. It descends in the evening and sets around 10 or 11 p.m. Below Jupiter twinkles orange Aldebaran, and a similar distance above Jupiter is El Nath (Beta Tauri). Bright Capella shines to the upper right from there. In a telescope, Jupiter has shrunk to a disappointing 34 arcseconds wide. April 30, 2013 -The small but distinctive constellation Corvus, the Crow, is an icon of spring evenings (in the Northern Hemisphere). Look for its four-star quadrilateral in the south-southeast after dark, to the right of Saturn and Spica. -Mars remains hidden in the glare of the Sun. Not until summer will it emerge in the dawn. April 29, 2013 -It's almost May, yet the winter star Sirius still twinkles low above the west-southwest horizon in late twilight. How much later into the spring can you keep it in view? -With your telescope, do you ever observe the lunar landscape when the Moon is waning before dawn and the terminator is lunar sunset rather than sunrise? Get up early this week and have a look at familiar features in this new light.  April 28, 2013 -The classic small-scope binary star Gamma Virginis, or Porrima, shines upper right of Spica, 14° from it (about a fist and a half at arm's length) these evenings. Porrima's two equal components were almost unresolvably close together for much of the last decade, but this spring they've widened to 2 arcseconds apart. Use high power. -Venus (magnitude –3.9) is just beginning an evening apparition that will continue for the rest of the year. How soon can you first pick it up? Use binoculars to look for Venus a mere 15 or 20 minutes after sunset, barely above the west-northwest horizon. It's far to the lower right of Jupiter for viewers at mid-northern latitudes. April 27, 2013 -The waning gibbous Moon rises in the southeast very late this evening, with the red supergiant Antares sparkling to its right. By early dawn Sunday morning Antares is below the Moon in the southwest. -Saturn (magnitude +0.1, in Libra) is at opposition Saturday night April 27th. All week it glows low in the east-southeast as twilight fades (to the lower left of Spica and farther lower right of Arcturus). It rises it higher all evening and shines highest in the south in the middle of the night. -Carefully note the brightness of the rings with respect to the globe. The rings always brighten for several days around opposition due to the Seeliger effect. The solid, very irregular particles of the rings preferentially reflect sunlight back in the direction it came from more than Saturn's cloudtops do. Watch as the rings dim back down later in the week, as Saturn moves away from the opposition point in Earth's sky. -The Seeliger effect: Christopher Go took these images of Saturn on March 2nd (top) and April 24th. Notice how the rings brightened with respect to the globe. And on the 24th, Saturn was still three days from opposition.  April 26, 2013 -Around the end of twilight this evening, the Moon rises below Saturn. With binoculars, look closer below Saturn for the wide double star Alpha2 and Alpha1 Librae, magnitudes 2.8 and 5.2, respectively. April 25, 2013 -Full Moon. A very slight partial lunar eclipse is visible from Europe, Africa, Australia, and most of Asia, centered on 20:07 April 25th Universal Time. Details are here: http://eclipse.gsfc.nasa.gov/OH/OH20...l#LE2013Apr25P The "star" near the Moon all night is Saturn, just two days away from its own opposition.   April 24, 2013 -Look close to the nearly full Moon for Spica tonight. The Moon occults Spica for parts of Central America, South America, and southern Africa.  April 23, 2013 -There's a bright gibbous Moon tonight. If you're out with a telescope, you'll notice that the Moon is creeping toward a star: Chi Virginis, magnitude 4.7. The Moon's invisible dark limb, just beyond the terminator, will occult the star for most of North America except the Northeast and north of the Great Lakes. Some times of the star's disappearance: at Washington, DC, 12:20 a.m. EDT; Miami, 11:58 p.m. EDT; Chicago, 10:47 p.m. CDT; Austin, 10:17 p.m. CDT; Denver, 9:07 p.m. MDT; Los Angeles, 7:52 p.m. PDT. April 22, 2013 -The two brightest points in the sky after dusk this week are Jupiter in the west and Sirius in the southwest. Midway between them is Orion. This lineup is lying down lower every week now. How late into the spring can you keep it in view?. April 21, 2013 -The Lyrid meteor shower should peak before dawn Monday morning local time. Most years it's quite weak, but there have been surprises. -This year the light of the nearly full Moon will interfere, but at least you can determine whether or not an outburst is in progress at the times you're looking. Watch late on the night of April 21st or before dawn's first light on April 22nd, when the shower's radiant (near Vega) is high in the sky.  April 20, 2013 -The Moon now shines under Regulus after dark. -Be on the lookout for the Lyrid Meteor Shower, slated to peak tomorrow. -Saturn (magnitude +0.1, in Libra) is nearing opposition. It glows low in the east-southeast as twilight fades, well to the lower left of Spica and farther lower right of brighter Arcturus. Saturn rises higher all evening and shines highest in the south around 1 a.m. daylight saving time. It's at opposition on the night of April 27th. -Carefully note the brightness of Saturn's rings with respect to the globe. Keep watch. The rings brighten for a few days around opposition due to the Seeliger effect: the solid particles of the rings preferentially reflect sunlight back in the direction it came from, more than Saturn's cloudtops do. -Below is Saturn on April 15th, imaged by Christopher Go in the Philippines using a Celestron 14 scope and a Point Grey Research monochrome Flea3 (ICX618) camera with Chroma Technology LRGB color filters. South is up. "The polar hexagon is prominent on this image," he writes. "Note the white spots on the North North Temperate Zone."   April 19, 2013 -Look for Regulus and the Sickle of Leo to the left of the Moon this evening, as shown here. April 18, 2013 -The Moon is exactly first quarter at 8:31 a.m. EDT this morning, which means it looks equally "first quarter" on the evenings of the 17th and 18th from North America's eastern time zones. The Moon this evening is in dim Cancer, inside the big, long triangle of Procyon, Pollux, and Regulus. April 17, 2013 -The Moon this evening is passing almost midway between Procyon to its lower left and Pollux to its upper right. Castor, slightly dimmer, shines to the right of Pollux. April 16, 2013 -Look left of the Moon after dark for Procyon. High above the Moon is Pollux, with Castor at its right. Equally far below the Moon is Betelgeuse, the top corner of Orion. -Saturn (magnitude +0.2, in Libra) glows low in the east-southeast by the end of twilight. Look for it well to the lower left of Spica, and farther lower right of brighter Arcturus. Saturn rises higher all evening. It shines highest in the south around 1 or 2 a.m. daylight saving time — more or less between Spica to its right, and Delta Scorpii (and then Antares) farther to its lower left. Saturn will reach opposition on the night of April 27th. April 15, 2013 -The Moon right after dark is in the top of Orion's very dim Club. That's not far from the center of the huge Winter Hexagon: Sirius, Procyon, the Pollux-and-Castor pair, Capella, Aldebaran (under Jupiter), Rigel, and back to Sirius. -Jupiter (magnitude –2.1, in Taurus) is the first "star" to come out in the west after sunset. It descends through the evening and sets around 11 or midnight. Below Jupiter is orange Aldebaran. Farther to Jupiter's lower right are the Pleiades. In a telescope, Jupiter has shrunk to just 35 arcseconds wide. April 14, 2013 -The Moon and Jupiter shine side by side high in the west after dusk, 3° or 4° apart, with Aldebaran below them. Although they look close together, the Moon is 1.3 light-seconds from Earth, Jupiter is currently 47 light-minutes distant, and Aldebaran is 65 light-years in the background.  April 13, 2013 -The thin crescent Moon floats between Aldebaran and the Pleiades in the west as twilight fades, with Jupiter above it, as shown at right. -Be on the look out for auroras based off the large CME the sun launched on April 11. The CME is expected to reach Earth at some point today. Pay attention to the aurora tracker as the day progresses. April 12, 2013 -As twilight fades in the west this evening, look far to the lower left of Jupiter for the crescent Moon. Less far above the Moon, you can see the Pleiades emerging into view. April 11, 2013 -Jupiter's moon Io reappears out of eclipse from Jupiter's shadow around 10:23 p.m. Eastern Daylight Time. Europa emerges from Jupiter's shadow around 10:11 p.m. Pacific Daylight Time. Both reappear just east of the planet. April 10, 2013 -By 10 p.m. or later (depending on where you live), the bright "Summer Star" Vega is rising in the northeast, beginning a long evening apparition that will continue for the rest of the year. -New Moon (exact at 5:35 a.m. EDT). -Jupiter is on its way to passing directly above Aldebaran and the Hyades. (The blue 10° scale is about the width of your fist at arm's length.)  April 9, 2013 -The upright Sickle of Leo, with Regulus on the bottom of its handle, crosses the meridian high in the south these evenings. It's shaped like a backward question mark, and it stands about 1½ fist-widths tall. -Jupiter is on its way to passing directly above Aldebaran and the Hyades. (The blue 10° scale is about the width of your fist at arm's length.) April 8, 2013 -As spring advances, wintry Orion tilts farther over as it declines in the west-southwest after dark. Orion's Belt in its middle is now almost horizontal. Orion is brightly framed on its right by Jupiter and on its left by Sirius. -Jupiter is on its way to passing directly above Aldebaran and the Hyades. (The blue 10° scale is about the width of your fist at arm's length.) April 7, 2013 -From bright Arcturus in the east, look lower right by about three fists at arm's length for Spica and, lower down as evening grows late, Saturn. To the right of Spica by a little more than a fist is the four-star quadrilateral of Corvus, the Crow. -Jupiter is on its way to passing directly above Aldebaran and the Hyades. (The blue 10° scale is about the width of your fist at arm's length.) April 6, 2013 -Look for Arcturus, the "Spring Star," low in the east-northeast in twilight and higher in the east after dark. The constellation Bootes extends to its left. High to Arcturus's upper left is the Big Dipper. -Just before dawn on April 4th, Sky&Telescope's Sean Walker took this image of Comet PanSTARRS passing 2.4° from M31, the Andromeda Galaxy. The galaxy is 2.5 million light-years away; the comet was 11 light-minutes away. Shooting from latitude 43° north in New Hampshire, Walker stacked 12 minutes of exposures (11 x 70 seconds) taken with a 180-mm lens at f/4 on a Canon 1000D camera at ISO 800.  April 5, 2013 -The huge, bright Winter Hexagon is still in view after dark, filling the sky to the southwest and west. Start at bright Sirius in the southwest. It marks the Hexagon's lower left corner. High above Sirius is Procyon. From there, look upper right to Pollux and Castor, lower right from Castor to Menkalinen and Capella, lower left to Aldebaran (with brighter Jupiter hogging the limelight near it!), lower left to Rigel at the bottom of Orion, and back to Sirius. April 4, 2013 -Venus and Mars remain hidden in the glare of the Sun -Jupiter (magnitude –2.1, in Taurus) comes into view high in the west after sunset, then descends as night grows late. Lower left of Jupiter is fainter orange Aldebaran. Farther to Jupiter's lower right are the Pleiades. They all set in the west-northwest around the middle of the night. In a telescope, Jupiter has shrunk to 36 arcseconds wide. April 3, 2013 -Jupiter's moon Io crosses Jupiter's face from 7:56 to 10:08 p.m. EDT, followed by its tiny black shadow (much more visible) from 9:03 to 11:15 p.m. EDT. -This evening Comet PanSTARRS, fading every day, is passing 2° west (lower right) of the Andromeda Galaxy, M31. They may appear about equally dim low in the northwest just as twilight is ending, for observers at fairly high northern latitudes. Think photo opportunity. April 2, 2013 -As spring advances, wintry Orion tilts farther over as it declines in the west-southwest after dark. Orion's Belt in its middle is almost horizontal. Orion is brightly framed between Jupiter on its right and Sirius on its left. -Last-quarter Moon tonight (exact at 12:37 a.m. Wednesday morning EDT). April 1, 2013  -Happy April Fools! The red carbon stars U and V Hydrae, and the Ghost of Jupiter planetary nebula (magnitude 7.7), all reside within a few degrees of each other in central Hydra.
March 31, 2013 -The red carbon stars U and V Hydrae, and the Ghost of Jupiter planetary nebula (magnitude 7.7), all reside within a few degrees of each other in central Hydra.If you have binoculars, this is a good time of year to view them. March 30, 2013 -Early Sunday morning, telescope users south of a line from central Florida through Oregon can watch the double star Beta Scorpii, magnitudes 2.6 and 4.8, emerge from behind the dark limb of the waning gibbous Moon. Map and timetables are found at the end of this post (for the bright component; the faint one emerges up to a minute or two earlier. Times are in Universal Time. Be sure to scroll down there to find the Reappearance timetable.) http://lunar-occultations.com/iota/bstar/0331zc2302.htm March 29, 2013 -The waning Moon rises in the east quite late this evening. Look above it for the planet Saturn. -This is the time of year when the dim Little Dipper juts to the right from Polaris (the Little Dipper's handle-end) during evening hours. The much brighter Big Dipper curls over high above it, "dumping water" into it.  March 28, 2013 -Once the Moon rises this evening, look upper right of it for Spica and lower left of it for Saturn, as shown at right. March 27, 2013 -With spring under way, Algol in Perseus is heading down in the northwest after dusk. Your last chance to catch Algol in one of its eclipses this season may be the one this evening or the one Saturday evening. Tonight Algol should be at minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 9:43 p.m. Pacific Daylight Time. Easterners will have a better shot on Saturday. Algol takes several additional hours to fade and to rebrighten. March 26, 2013 -Full Moon tonight (exact at 5:27 a.m. Wednesday morning EDT). The Moon this evening is far below Leo and above Spica and Corvus. -Mercury (brightening from magnitude +0.6 to +0.2 this week) is having a poor apparition very low in the dawn. Use binoculars to scan for it just above the east-southeast horizon about 30 minutes before sunrise. March 25, 2013 -Look northwest right after dark for W-shaped Cassiopeia standing on end. The brightest part of the W is on the bottom. -Jupiter (magnitude –2.1, in Taurus) comes into view high in the west after sunset, then descends as night grows late. Lower left of Jupiter is orange Aldebaran. Farther to Jupiter's lower right are the Pleiades. They all set in the west-northwest around the middle of the night. -Jupiter is not as bright as it used to be, and in a telescope it has shrunk to 36 arcseconds wide – from 48" around its opposition last December.  March 24, 2013 -Look above the Moon this evening for Regulus. It's the bottom star of the Sickle of Leo. -Saturn (magnitude +0.3, in Libra) rises in the east-southeast only about an hour after the end of twilight now. Watch for it to make its appearance well to the lower left of Spica, and farther to the lower right of brighter Arcturus. Saturn shines highest in the south around 3 a.m. daylight saving time — more or less between Spica to its right, and Delta Scorpii and than Antares farther to its lower left. Saturn will come to opposition on the night of April 27th. March 23, 2013 -Mercury (brightening from magnitude +0.6 to +0.2 this week) is having a poor apparition very low in the dawn. Use binoculars to scan for it just above the east-southeast horizon about 30 minutes before sunrise. -Left of the Moon this evening are Regulus and the Sickle of Leo, as shown here. Farther lower right of the Moon is Alphard, the heart of Hydra. To the right or upper right of the Moon, can you make out Hydra's dim head? March 22, 2013 -Now that spring is here, Orion is in the southwest after dark and leaning over to slide soon down to the horizon. Orion's three-star belt is turning nearly horizontal. He is framed by the two brightest starlike points in the sky: Jupiter off to his right and Sirius to his left. -As the Moon waxes toward full, it walks between Leo and mostly-dim Hydra. March 21, 2013 -High in the south after dusk, the Moon forms part of a big arc with Pollux and Castor to its upper right and Procyon below it. -Saturn (magnitude +0.3, in Libra) rises in the east-southeast around 11 p.m. daylight saving time. Watch for it rising well to the lower left of Spica and farther to the lower right of brighter Arcturus. Saturn shines highest in the south in the early morning hours — more or less between Spica to its right and Antares farther to its lower left. Saturn will come to opposition on the night of April 27th. In a telescope, Saturn's rings are now tilted a wide 19° from our line of sight. March 20, 2013 -Comet PanSTARRS, for all the attention it's receiving, has turned out to be barely visible to the unaided eye, and only if you know exactly where to look. That would be low in twilight, due west or just a little to the right of due west now, about 45 minutes after sunset. This week the comet starts fading even as it gains a bit more altitude as seen from the world's mid-northern latitudes. Bring binoculars or, better, a low-power, wide-field telescope. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here.  Source: Comet PanSTARRS on March 17th. Earth's changing viewpoint toward its flat, thin dust tail is making the tail appear wider. Note the hint of a thin, straight ion (gas) tail just to the right of the curving dust tail's edge. Enhanced images show that it's real. -Face southwest after dark. Very high there shines the Moon. Even higher (depending on where you live) are Pollux and Castor. To the Moon's left or lower left is Procyon. -Spring begins in the Northern Hemisphere at the equinox, 7:02 a.m. EDT, when the Sun crosses the equators of both Earth and sky heading north for the year. In the Southern Hemisphere, fall begins. March 19, 2013 -Comet PanSTARRS, for all the attention it's receiving, has turned out to be barely visible to the unaided eye, and only if you know exactly where to look. That would be low in twilight, due west or just a little to the right of due west now, about 45 minutes after sunset. This week the comet starts fading even as it gains a bit more altitude as seen from the world's mid-northern latitudes. Bring binoculars or, better, a low-power, wide-field telescope. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -First-quarter Moon (exact at 1:27 p.m. EDT). This evening the Moon shines between the feet of Gemini and the top of Orion's Club. March 18, 2013 -Comet PanSTARRS, for all the attention it's receiving, has turned out to be barely visible to the unaided eye, and only if you know exactly where to look. That would be low in twilight, due west or just a little to the right of due west now, about 45 minutes after sunset. This week the comet starts fading even as it gains a bit more altitude as seen from the world's mid-northern latitudes. Bring binoculars or, better, a low-power, wide-field telescope. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -Look lower right of the Moon this evening for Jupiter, and upper right of the Moon for Beta Tauri (El Nath).  March 17, 2013 -Comet PanSTARRS, for all the attention it's receiving, has turned out to be barely visible to the unaided eye, and only if you know exactly where to look. That would be low in twilight, due west or just a little to the right of due west now, about 45 minutes after sunset. This week the comet starts fading even as it gains a bit more altitude as seen from the world's mid-northern latitudes. Bring binoculars or, better, a low-power, wide-field telescope. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -The Moon this evening passes right between Jupiter and Aldebaran, depending on your location. Gathered around are the Hyades, and nearby are the Pleiades. Think photo opportunity. -Watch the Moon wax to, and through, the evening Jupiter group. (Drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. The Moon is shown three times its actual size.) March 16, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -After dusk, the waxing Moon shines in the west with the Pleiades to its upper right and Jupiter and Aldebaran farther to its upper left, as shown here. -Watch the Moon wax to, and through, the evening Jupiter group. (Drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. The Moon is shown three times its actual size.) March 15, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here.   Yesterday night instead of playing my tournament song for hours and hours I ventured out into one of the larger parks the city has, Downsview Park for a couple hours to spot Comet PANSTARRS. Two of the resulting images are shown here - one with a distant plane crossing in the distance, the other with an actual size view of PANSTARRS in the distance with a hydro pole as perspective. -Look high above the Moon after dark for the Pleiades. Upper left of the Pleiades shines bright Jupiter with Aldebaran to its left, as shown here. -As soon as it gets dark now, the Big Dipper has climbed as high in the northeast as Cassiopeia has sunk in the northwest. -Watch the Moon wax to, and through, the evening Jupiter group. (Drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. The Moon is shown three times its actual size.) March 14, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here.  Source:* Piotr Potepa in Torun, Poland, caught this image March 13th in bright twilight using a Nikon D700 for a 3-second exposure. The thin crescent moon owns the night, and the photographer nicely reaches out to the comet. -The place to look for PanSTARRS now is two fists below the crescent Moon in twilight and perhaps a bit to the right. March 13, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here.  Jose Galvez in Washington DC, USA, caught this image March 12th in bright twilight using a SONY DSC-HX200V for a 7-second exposure. The thin crescent moon and comet are clearly visible side by side. -Comet PanSTARRS is now below the thickening crescent Moon 30 to 45 minutes after sunset, by about a fist-width at arm's length. March 12, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. An accurate visual representation of what you can expect Comet PANSTARRS to look like in the bright twilight:  Toni Scarmato in Calabria, Italy, latitude 38°, caught this image March 10th in bright twilight using a 300-mm telephoto lens for a 1-second exposure. The frame is just 2.8° tall. -Look very low in the west about 30 minutes after sunset for the thin waxing crescent Moon, not much more than 24 hours old, as shown at right. As seen from North America, Comet PanSTARRS is now left of the Moon by two or three finger-widths at arm's length. It's a hazy "star" with a thin, upward pointing tail only about 1° long. Bring binoculars for a better view. -And think photo opportunity! Use a long or zoomed-out lens, and put your camera on a tripod because with a long lens in twilight, exposures won't be short. Experiment with a variety of exposures. March 11, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. An accurate visual representation of what you can expect Comet PANSTARRS to look like in the bright twilight: Toni Scarmato in Calabria, Italy, latitude 38°, caught this image March 10th in bright twilight using a 300-mm telephoto lens for a 1-second exposure. The frame is just 2.8° tall. -It being March, bright Sirius is highest in the south on the meridian after dark. Sirius is the closest naked-eye star that's ever visible from mid-northern latitudes (aside from the Sun). It's only 8.6 light-years away. -Using binoculars, look below Sirius by almost a binocular field-of-view for a dimly glowing patch among the stars. This is the open star cluster M41, 2,200 light-years away. New Moon (exact at 3:51 p.m. Eastern Daylight Time). March 10, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -It's still winter, and in early evening Vega, the "Summer Star," is nowhere to be seen. But you can always tell where it is. Once again, find the Big Dipper standing in the northeast. The middle star of the Dipper's bent handle is Mizar, with faint little Alcor barely to its lower left. A line from Mizar through Alcor always points to Vega — currently well below the north horizon. -Daylight-saving time begins at 2 a.m. Sunday morning in most of North America. Clocks spring ahead an hour. March 9, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -The Big Dipper glitters high in the northeast these evenings, standing on its handle. You probably know that the two stars forming the front of the Dipper's bowl (currently on top) are the Pointers; they point to Polaris, currently to their left. And, you may know that if you follow the curve of the Dipper's handle out and around by a little more than a Dipper length, you'll arc to Arcturus, now rising in the east. But did you know that if you follow the Pointers backward the opposite way, you'll land in Leo? Draw a line diagonally across the Dipper's bowl from where the handle is attached, continue far on, and you'll go to Gemini. And look at the two stars forming the open top of the Dipper's bowl. Follow this line past the bowl's lip far across the sky, and you crash into Capella. March 8, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -Jupiter is 5° from Aldebaran high in the west after dark. But it's now passing only 2° from fainter (3.5-magnitude) Epsilon Tauri, the other tip of the Hyades V pattern, located almost between them. March 7, 2013 -Comet PANSTARRS now makes its way to the northern hemisphere - however depending on your location it will be difficult to spot today and tomorrow. -Look west after sunset near the horizon. Binoculars may be needed to pick Comet PanSTARRS out of the bright sky. Look too early and the sky will be too bright; too late and the comet will be too low. On the altitude scale at left, 10° is about the width of your fist held at arm's length. -This diagram is drawn for a viewer near 40° north latitude (Denver, New York, Madrid) 30 minutes after sunset. If you're south of there, the comet will be a little higher above your horizon early in the month than shown here. North of 40°, it will be a little lower early in March than shown here. -Algol in Perseus should be at minimum light, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 9:58 p.m. Eastern Standard Time. Algol takes several additional hours to fade and to rebrighten. March 6, 2013 -Mercury, Venus, and Mars are hidden in the glare of the Sun. -Jupiter (bright at magnitude –2.3, in Taurus) comes into view high in the south-southwest after sunset and dominates the southwest to west later in the evening. Left of Jupiter is orange Aldebaran; farther to its lower right are the Pleiades. They all set in the west-northwest around midnight or 1 a.m. In a telescope, Jupiter is shrinking as Earth pulls farther ahead of it in our faster orbit around the Sun. This week it shrinks from 39 to 38 arcseconds wide. March 5, 2013 -On the traditional divide between the winter and spring sky is the dim constellation Cancer. It's between Gemini to its west and Leo to its east. Cancer has a unique feature: the Beehive Star Cluster, M44, in its middle. The Beehive shows to the naked eye only if your light pollution is slight. Look for it a little less than halfway from Pollux to Regulus. With binoculars it's a snap. March 4, 2013 [left]-With Sirius on the meridian after dinnertime, so is the Winter Triangle — since Sirius is its bottom corner. The other two are Procyon to its upper left and Betelgeuse to its upper right. The Winter Triangle is almost perfectly equilateral: all three stars are 26° from each other within about 1° accuracy. -Last-quarter Moon (exact at 4:53 p.m. EST). March 3, 2013 -Jupiter's moon Europa disappears into eclipse by Jupiter's shadow around 7:10 p.m. EST, after reappearing from behind Jupiter's eastern limb just 14 minutes earlier. Io disappears behind Jupiter's other side 10 minutes later. Europa then reappears out of eclipse at 9:38 p.m. EST, followed by Io at 10:50 p.m. EST. March 2, 2013 -Now that March has begun, Sirius takes over from Orion to stand at its highest in the south soon after dark  March 1, 2013 -Around 11 p.m. this evening (depending on where you live), the waning Moon rises with Saturn glowing a few degrees to its left, as shown above. The pair remain close for the rest of the night. -Long awaited, Comet PanSTARRS now looks likely to reach about 2nd magnitude at its best in mid-March, when it will be low in the western evening twilight for Northern Hemisphere observers. Astro Pic of the Day Archive March 1, 2013 - July 31, 2013 July 31, 2013 How has the surface temperature of Earth been changing? To help find out, Earth scientists collected temperature records from over 1000 weather stations around the globe since 1880, and combined them with modern satellite data. The above movie dramatizes the result showing 130 years of planet-wide temperature changes relative to the local average temperatures in the mid-1900s. In the above global maps, red means warmer and blue means colder. On average, the display demonstrates that the temperature on Earth has increased by nearly one degree Celsius over the past 130 years, and many of the warmest years on record have occurred only recently. Global climate change is of more than passing interest - it is linked to global weather severity and coastal sea water levels. July 30, 2013  In 1787, astronomer William Herschel discovered the Eskimo Nebula. From the ground, NGC 2392 resembles a person's head surrounded by a parka hood. In 2000, the Hubble Space Telescope imaged the Eskimo Nebula in visible light, while the nebula was imaged in X-rays by the Chandra X-ray Observatory in 2007. The above combined visible-X ray image, with X-rays emitted by central hot gas and shown in pink, was released last week. From space, the nebula displays gas clouds so complex they are not fully understood. The Eskimo Nebula is clearly a planetary nebula, and the gas seen above composed the outer layers of a Sun-like star only 10,000 years ago. The inner filaments visible above are being ejected by strong wind of particles from the central star. The outer disk contains unusual light-year long orange filaments. The Eskimo Nebula spans about 1/3 of a light year and lies in our Milky Way Galaxy, about 3,000 light years distant, toward the constellation of the Twins (Gemini). July 29, 2013  This is not a solar eclipse. Pictured above is a busy vista of moons and rings taken at Saturn. The large circular object in the center of the image is Titan, the largest moon of Saturn and one of the most intriguing objects in the entire Solar System. The dark spot in the center is the main solid part of the moon. The bright surrounding ring is atmospheric haze above Titan, gas that is scattering sunlight to a camera operating onboard the robotic Cassini spacecraft. Cutting horizontally across the image are the rings of Saturn, seen nearly edge on. At the lower right of Titan is Enceladus, a small moon of Saturn. Since the image was taken pointing nearly at the Sun, the surfaces of Titan and Enceladus appear in silhouette, and the rings of Saturn appear similar to a photographic negative. Now if you look really really closely at Enceladus, you can see a hint of icy jets shooting out toward the bottom of the image. It is these jets that inspired future proposals to land on Enceladus, burrow into the ice, and search for signs of extraterrestrial life. July 28, 2013  Is this one galaxy or two? This question came to light in 1950 when astronomer Art Hoag chanced upon this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder stars that are likely much older. Between the two is a gap that appears almost completely dark. How Hoag's Object formed remains unknown, although similar objects have now been identified and collectively labeled as a form of ring galaxy. Genesis hypotheses include a galaxy collision billions of years ago and the gravitational effect of a central bar that has since vanished. The above photo taken by the Hubble Space Telescope in July 2001 revealed unprecedented details of Hoag's Object. More recent observations in radio waves indicate that Hoag's Object has not accreted a smaller galaxy in the past billion years. Hoag's Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of the Snake (Serpens). Coincidentally, visible in the gap (at about one o'clock) is yet another ring galaxy that likely lies far in the distance. July 27, 2013  Storm clouds do sometimes come to Chile's Atacama desert, known as the driest place on Earth. These washed through the night sky just last month during the winter season, captured in this panoramic view. Drifting between are cosmic clouds more welcome by the region's astronomical residents though, including dark dust clouds in silhouette against the crowded starfields and nebulae of the central Milky Way. Below and right of center lies the Large Magellanic Cloud, appropriately named for its appearance in starry southern skies. City lights about 200 kilometers distant still glow along the horizon at the right, while bright star Canopus shines above them in the cloudy sky. July 26, 2013  The Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. The cosmic elephant's trunk is over 20 light-years long. This composite was recorded through narrow band filters that transmit the light from ionized hydrogen, sulfur, and oxygen atoms in the region. The resulting image highlights the bright swept-back ridges that outline pockets of cool interstellar dust and gas. Such embedded, dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within the obscuring cosmic dust. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees. This close-up mosaic covers a 2 degree wide field, about the size of 4 Full Moons. July 25, 2013  The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid illustrates three different types of astronomical nebulae; red emission nebulae dominated by light emitted by hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. The bright red emission region, roughly separated into three parts by obscuring dust lanes, lends the Trifid its popular name. But in this sharp, colorful scene, the red emission is also surrounded by the the telltale blue haze of reflection nebulae. Pillars and jets sculpted by newborn stars, below and left of the emission nebula's center, appear in Hubble Space Telescope close-up images of the region. The Trifid Nebula is about 40 light-years across. July 24, 2013 Source: Each panel shows one day. With 360 movie panels, the sky over (almost) an entire year is shown in time lapse format as recorded by a video camera on the roof of the Exploratorium museum in San Francisco, California. The camera recorded an image every 10 seconds from before sunrise to after sunset and from mid-2009 to mid-2010. A time stamp showing the local time of day is provided on the lower right. The videos are arranged chronologically, with July 28 shown on the upper left, and January 1 located about about half way down. Although every day lasts 24 hours, daylight lasts longest in the northern hemisphere in June and the surrounding summer months, a fact which can be seen here as the bottom (and soon top) videos are the first to light up with dawn. The initial darkness in the middle depicts the delayed dawn and fewer daylight hours of winter. In the videos, darkness indicates night, blue depicts clear day, while gray portrays pervasive daytime cloud cover. Many videos show complex patterns of clouds moving across the camera's wide field as that day progresses. As the videos collectively end, sunset and then darkness descend first on the winter days just above the middle, and last on the mid-summer near the bottom. July 23, 2013  In a cross-Solar System interplanetary first, our Earth was photographed during the same day from both Mercury and Saturn. Pictured on the left, Earth is the pale blue dot just below the rings of Saturn, as captured by the robotic Cassini spacecraft now the gas giant. Pictured on the right, the Earth-Moon system is seen against a dark background, as captured by the robotic MESSENGER spacecraft now orbiting Mercury. In the MESSENGER image, the Earth (left) and Moon (right) shine brightly with reflected sunlight. MESSENGER took the overexposed image last Friday as part of a search for small natural satellites of the innermost planet, moons that would be expected to be quite dim. The picture of Earth is only one footprint in a mosaic of 33 footprints covering the entire Saturn ring system. Researchers are working on the ensemble now, and they expect it to be ready in a few weeks. July 22, 2013  You are here. Everyone you've ever known is here. Every human who has ever lived - is here. Pictured above is the Earth-Moon system as captured by the Cassini mission orbiting Saturn in the outer Solar System. Earth is the brighter of the two spots near the center, while the Moon is visible to its lower left. The unprocessed image shows several streaks that are not stars but rather cosmic rays that struck the digital camera while it was taking the image. The image was snapped by Cassini on Friday and released on Saturday. At nearly the same time, many humans on Earth were snapping their own pictures of Saturn. July 21, 2013  Since Saturn's axis is tilted as it orbits the Sun, Saturn has seasons, like those of planet Earth ... but Saturn's seasons last for over seven years. So what season is it on Saturn now? Orbiting the equator, the tilt of the rings of Saturn provides quite a graphic seasonal display. Each year until 2016, Saturn's rings will be increasingly apparent after appearing nearly edge-on in 2009. The ringed planet is also well placed in evening skies providing a grand view as summer comes to Saturn's northern hemisphere and winter to the south. The Hubble Space Telescope took the above sequence of images about a year apart, starting on the left in 1996 and ending on the right in 2000. Although they look solid, Saturn's Rings are likely less than 50 meters thick and consist of individually orbiting bits of ice and rock ranging in size from grains of sand to barn-sized boulders. July 20, 2013  Now sweeping high above the ecliptic plane, Comet Lemmon has faded dramatically in planet Earth's night sky as it heads for the outer solar system. Some 16 light-minutes (2 AU) from the Sun, it still sports a greenish coma though, posing on the right in this 4 degree wide telescopic view from last Saturday with deep sky star clusters and nebulae in Cassiopeia. In fact, the rich background skyscape is typical within the boundaries of the boastful northern constellation that lie along the crowded starfields of the Milky Way. Included near center is open star cluster M52 about 5,000 light-years away. Around 11,000 light-years distant, the red glowing nebula NGC 7635 below and left of M52 is well-known for its appearance in close-up images as the Bubble Nebula. But the fading Comet Lemmon is not the only foreground object on the scene. A faint streak on the right is an orbiting satellite caught crossing through the field during the long exposure, glinting in the sunlight and winking out as it passes into Earth's shadow. July 19, 2013  Take a picture of Saturn in the sky tonight. You could capture a view like this one. Recorded just last month looking toward the south, planet Earth and ruins of the ancient temple of Athena at Assos, Turkey are in the foreground. The Moon rises at the far left of the frame and Saturn is the bright "star" at the upper right, near Virgo's alpha star Spica (picture with labels). If you do take a picture of Saturn or wave at Saturn and take a picture, you can share it online and submit it to the Saturn Mosaic Project. Why take a picture tonight? Because the Cassini spacecraft will be orbiting Saturn and taking a picture of you. http://saturn.jpl.nasa.gov/news/waveatsaturn/ July 18, 2013  Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and dust clouds along the plane of our own Milky Way galaxy. Even though IC 342's light is dimmed by intervening cosmic clouds, this deep telescopic image traces the galaxy's obscuring dust, blue star clusters, and glowing pink star forming regions along spiral arms that wind far from the galaxy's core. IC 342 may have undergone a recent burst of star formation activity and is close enough to have gravitationally influenced the evolution of the local group of galaxies and the Milky Way. July 17, 2013  Since 2011, the Earth to Sky students have flown 30 balloons and measured the temperature of the tropopause 19 times.The temperature of the tropopause on June 30, 2013 during a huge heat wave, fell right in the middle of their overall distribution - nothing unusual. These results show that hot air on the ground does not necessarily translate into a hot upper atmosphere. There was, however, something unusual about the flight. Normally, air above the Sierra launch site is crystal clear, but not this time. En route to the stratosphere, the balloon encountered many thin layers of smoke and ash blown into the area from distant wildfires. Each fire, apparently, lofted its aerosols to a different altitude where winds stretched the smoky debris into a thin layer. This picture was captured while the balloon was in transit between two layers. Note the curved blue line. That's the narrow gap between the two aerosol layers, allowing a glimpse of blue sky in the distance. (To residents of the eastern Sierra: That's Crowley Lake in the foreground.) July 16, 2013  Which moon is this? Earth's. Our Moon's unfamiliar appearance is due partly to an unfamiliar viewing angle as captured by a little-known spacecraft - the Soviet Union's Zond 8 that circled the Moon in October of 1970. Pictured above, the dark-centered circular feature that stands out near the top of the image is Mare Orientale, a massive impact basin formed by an ancient collision with an asteroid. Mare Orientale is surrounded by light colored and highly textured highlands. Across the image bottom lies the dark and expansive Oceanus Procellarum, the largest of the dark (but dry) maria that dominate the side of the Moon that always faces toward the Earth. Originally designed to carry humans, robotic Zond 8 came within 1000 km of the lunar surface, took about 100 detailed photographs on film, and returned them safely to Earth within a week. July 15, 2013  What's going on in the center of this spiral galaxy? Named the Sombrero Galaxy for its hat-like resemblance, M104 features a prominent dust lane and a bright halo of stars and globular clusters. Reasons for the Sombrero's hat-like appearance include an unusually large and extended central bulge of stars, and dark prominent dust lanes that appear in a disk that we see nearly edge-on. Billions of old stars cause the diffuse glow of the extended central bulge visible in the above image from the 200-inch Hale Telescope. Close inspection of the central bulge shows many points of light that are actually globular clusters. M104's spectacular dust rings harbor many younger and brighter stars, and show intricate details astronomers don't yet fully understand. The very center of the Sombrero glows across the electromagnetic spectrum, and is thought to house a large black hole. Fifty million-year-old light from the Sombrero Galaxy can be seen with a small telescope towards the constellation of Virgo. July 14, 2013  What lights up this castle of star formation? The familiar Eagle Nebula glows bright in many colors at once. The above image is a composite of three of these glowing gas colors. Pillars of dark dust nicely outline some of the denser towers of star formation. Energetic light from young massive stars causes the gas to glow and effectively boils away part of the dust and gas from its birth pillar. Many of these stars will explode after several million years, returning most of their elements back to the nebula which formed them. This process is forming an open cluster of stars known as M16. July 13, 2013  Reddened rays of the setting Sun flooded the skies over Cedar Creek Lake, southeast of Dallas, Texas, planet Earth on July 6th. And while sunsets may be the most watched celestial event, this one even offered something extra. A sunspot so large it was visible to the naked eye is captured in the serene sunset view, near the center of a solar disk dimmed and distorted by Earth's dense atomosphere. Telescopic views revealed the spot to be a complex of large solar active regions composed of sunspots, some larger than planet Earth itself. July 12, 2013   This fifteen degree wide field of view stretches across the crowded starfields of Sagittarius toward the center of our Milky Way galaxy. In fact, the center of the galaxy lies near the right edge of the rich starscape and eleven bright star clusters and nebulae fall near the center of the frame. All eleven are numbered entries in the catalog compiled by 18th century cosmic tourist Charles Messier. Achieving celebrity status for skygazers, M8 (Lagoon), M16 (Eagle), M17 (Omega), and M20 (Trifid) show off the telltale reddish hues of emission nebulae associated with star forming regions. But also eye-catching in small telescopes are star clusters in the crowded region; M18, M21, M22, M23, M25, and M28. Broader in extent than the star clusters themselves, M24 is actually a cloud of the Milky Way's stars thousands of light-years long, seen through a break in the galaxy's veil of obscuring dust. You can put your cursor over the image (or click here) for help identifying Messier's eleven. July 11, 2013  This complex of dusty nebulae linger along the edge of the Taurus molecular cloud, a mere 450 light-years distant. Stars are forming on the cosmic scene, including extremely youthful star RY Tauri prominent toward the upper left of the 1.5 degree wide telescopic field. In fact RY Tauri is a pre-main sequence star, embedded in its natal cloud of gas and dust, also cataloged as reflection nebula vdB 27. Highly variable, the star is still relatively cool and in the late phases of gravitational collapse. It will soon become a stable, low mass, main sequence star, a stage of stellar evolution achieved by our Sun some 4.5 billion years ago. Another pre-main sequence star, V1023 Tauri, can be spotted below and right, embedded in its yellowish dust cloud adjacent to the striking blue reflection nebula Ced 30. July 10, 2013  One of the largest sunspot regions in recent years is now crossing the Sun. This region of convoluted magnetic fields may well produce a solar flare that releases a cloud of energetic particles into the Solar System. Were a very powerful cloud to impact the Earth's magnetosphere, it could be dangerous to Earth-orbiting astronauts and satellites. Conversely, the impact of even a less energetic cloud might create picturesque aurora. Pictured above is the sunspot region as it appeared two days ago. The rightmost part of this region has been cataloged as AR 11785, while the left part as AR 11787. The darkest sunspot regions contain nearly vertical magnetic fields and are called umbras, while the surrounding bronze regions - more clearly showing stringy magnetic flux tubes - are called penumbras. Churning solar granules, many about 1000 km across, compose the yellow background region. No one knows what this sunspot region will do, but space weather researchers are monitoring it closely. July 9, 2013  Supergiant star Gamma Cygni lies at the center of the Northern Cross, a famous asterism in the constellation of the Swan (Cygnus). Known by the proper name Sadr, the bright star also lies at the center of this gorgeous skyscape, featuring a complex of stars, dust clouds, and glowing nebulae along the plane of our Milky Way galaxy. The field of view spans over 3 degrees (six Full Moons) on the sky and includes emission nebula IC 1318 and open star cluster NGC 6910. Left of Gamma Cygni and shaped like two glowing cosmic wings divided by a long dark dust lane, IC 1318's popular name is understandably the Butterfly Nebula. Above and slightly left of Gamma Cygni, are the young, still tightly grouped stars of NGC 6910. Some distance estimates for Gamma Cygni place it at around 750 light-years while estimates for IC 1318 and NGC 6910 range from 2,000 to 5,000 light-years. July 8, 2013  Pluto's newly discovered moons now have names. Known previously as P4 and P5, the International Astronomical Union has now given the fourth and fifth discovered moons of Pluto the names Kerberos and Styx. The small moons were discovered in 2011 and 2012 by the Hubble Space Telescope in preparation for the close passing of the New Horizons spacecraft by Pluto in 2015. Keberos is named for the many headed dog in Greek mythology that guards the entrance to the underworld, while Styx is named for the goddess who overlooks the mythological river that runs between the Earth and the underworld. Both monikers are related to the name of Pluto, who rules the mythical nether region. Because their reflectively is unknown, the size of each moon is quite uncertain - but each is crudely estimated to be about 20 kilometers in diameter. The robotic New Horizons spacecraft is on schedule to pass by Pluto in 2015 and provide the first clear images of the dwarf planet and its companions. July 7, 2013  In this beautiful celestial still life composed with a cosmic brush, dusty nebula NGC 2170 shines at the upper left. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae, a compact red emission region, and streamers of obscuring dust against a backdrop of stars. Like the common household items still life painters often choose for their subjects, the clouds of gas, dust, and hot stars pictured here are also commonly found in this setting - a massive, star-forming molecular cloud in the constellation of the Unicorn (Monoceros). The giant molecular cloud, Mon R2, is impressively close, estimated to be only 2,400 light-years or so away. At that distance, this canvas would be about 15 light-years across. July 6, 2013  The universe is filled with galaxies. But to see them astronomers must look out beyond the stars of our own galaxy, the Milky Way. This colorful Hubble Space Telescopic portrait features spiral galaxy NGC 6384, about 80 million light-years away in the direction of the constellation Ophiuchus. At that distance, NGC 6384 spans an estimated 150,000 light-years, while the Hubble close-up of the galaxy's central region is about 70,000 light-years wide. The sharp image shows details in the distant galaxy's blue star clusters and dust lanes along magnificent spiral arms, and a bright core dominated by yellowish starlight. Still, the individual stars seen in the picture are all in the relatively close foreground, well within our own galaxy. The brighter Milky Way stars show noticeable crosses, or diffraction spikes, caused by the telescope itself. July 5, 2013  Some 13,000 light-years away toward the southern constellation Pavo, the globular star cluster NGC 6752 roams the halo of our Milky Way galaxy. Over 10 billion years old, NGC 6752 follows clusters Omega Centauri and 47 Tucanae as the third brightest globular in planet Earth's night sky. It holds over 100 thousand stars in a sphere about 100 light-years in diameter. Telescopic explorations of the NGC 6752 have found that a remarkable fraction of the stars near the cluster's core, are multiple star systems. They also reveal the presence of blue straggle stars, stars which appear to be too young and massive to exist in a cluster whose stars are all expected to be at least twice as old as the Sun. The blue stragglers are thought to be formed by star mergers and collisions in the dense stellar environment at the cluster's core. This sharp color composite also features the cluster's ancient red giant stars in yellowish hues. July 4, 2013  Also known as the Cigar Galaxy for its elongated visual appearance, M82 is a starburst galaxy with a superwind. In fact, through ensuing supernova explosions and powerful winds from massive stars, the burst of star formation in M82 is driving a prodigious outflow of material. Evidence for the superwind from the galaxy's central regions is clear in this sharp telescopic snapshot. The composite image highlights emission from long outflow filaments of atomic hydrogen gas in reddish hues. Some of the gas in the superwind, enriched in heavy elements forged in the massive stars, will eventually escape into intergalactic space. Including narrow band image data in the deep exposure has revealed a faint feature dubbed the cap. Perched about 35,000 light-years above the galaxy at the upper left, the cap appears to be galactic halo material ionized by the superwind shock or intense ultraviolet radiation from the young, massive stars in the galaxy's core. Triggered by a close encounter with nearby large galaxy M81, the furious burst of star formation in M82 should last about 100 million years or so. M82 is 12 million light-years distant, near the northern boundary of Ursa Major. July 3, 2013  It may appear, at first, like the Galaxy is producing the lightning, but really it's the Earth. In the foreground of the above picturesque nighttime landscape is the Greek Island of Corfu, with town lights surrounding Lake Korrision. Visible farther in the distance are lights from the town of Preveza on the Greek mainland. In the more distant sky a thunderstorm is threatening, with two lightning strokes caught together during this 45 second wide-angle exposure taken in mid-May. The lightning branch on the left appears to be striking near Preveza, whereas the lightning strike on the right appears to be striking near Mount Ainos on the Greek Island of Cephalonia. Much farther in the distance, strewn about the sky, are hundreds of stars in the neighborhood of our Sun in the Milky Way Galaxy. Furthest away, arching over the entire panorama, are billions of stars that together compose the central band of our Milky Way. July 2, 2013 What would it look like to go right up to a black hole? One particularly interesting place near a black hole is its photon sphere, where photons can orbit in circles, a sphere 50 percent further out than the event horizon. Were you to look out from the photon sphere of a black hole, half of the sky would appear completely black, half of the sky would appear unusually bright, and the back of your head would appear across the middle. The above computer-animated video depicts this view from the photon sphere. The reason that the lower region, as shown, appears black is because all light paths from this dark region comes up from the black hole - which classically emits no light. The upper half of the sky now appears unusually bright, blueshifted, and shows increasingly many complete sky images increasingly close to the dark-light divide across the middle. That dark-light divide is the photon sphere - your location - and since photons can do circles there, light from the back of your head can circle the black hole and come to your eye. No place on the sky is hidden from you - stars that would normally pass behind the black hole now appear to zip quickly around an Einstein ring, a ring that appears above as a horizontal line about a quarter of the way down from the video top. (Disclosure: Video creator Robert Nemiroff is an editor for APOD.) July 1, 2013  On June 28, Earth passed through a region of south-pointing magnetism in the solar wind. The encounter set off one of the finest geomagnetic storms of the current solar cycle. At its peak on June 29th, the strong (Kp=7) storm filled the sky over Alberta Canasa with bright green auroras: "With advance warning from Spaceweather.com, I headed out Friday night to a wind farm near my rural home, to take images of what I hoped would be an all-sky aurora. It did not disappoint!" says photographer Alan Dyer of Drumheller, Alberta. "These images are taken from the base of one of the massive wind machines, seemingly aimed into the aurora blown by the solar wind." For a brief time, the auroras spilled across the Canadian border into the USA as south as Iowa, Oregon, Nebraska, and Kansas. In total, observers in more than a dozen US states reported visual or photographic sightings of auroras. June 30, 2013  What lies at the bottom of Hyperion's strange craters? Nobody's sure. To help find out, the robot Cassini spacecraft now orbiting Saturn swooped past the sponge-textured moon in 2005 and 2010 and took images of unprecedented detail. An image from the 2005 pass, shown above in false color, shows a remarkable world strewn with strange craters and a generally odd surface. The slight differences in color likely show differences in surface composition. At the bottom of most craters lies some type of unknown dark material. Inspection of the image shows bright features indicating that the dark material might be only tens of meters thick in some places. Hyperion is about 250 kilometers across, rotates chaotically, and has a density so low that it might house a vast system of caverns inside. June 29, 2013  Once known as Earth's sunset comet, PanSTARRS (C/2011 L4) is up all night now, but only for northern hemisphere skygazers. Telescopes are required to track its progress as it fades and heads for the outer solar system. But because planet Earth passed through the comet's orbital plane in late May, PanSTARRS will also be remembered for its remarkably long anti-tail. That edge-on perspective looking along the broad, fanned-out dust tail as it trailed behind the comet created the appearance of an anti-tail pointing in the sunward direction, back toward the inner solar system. Recorded on the night of May 27, this 13 pane mosaic (shown in positive and negative views) follows PanSTARRS' anti-tail as it stretches over 7 degrees from the comet's coma at the far right. The anti-tail was likely much longer, but gets lost in the evening's bright moonlight encroaching on the left edge of the scene. Background star cluster NGC 188 in Cepheus shows up along the way, near top left. June 28, 2013  A Full Perigee Moon rose as the Sun set last Sunday. At its closest to Earth it was, by just a bit, the year's brightest and largest Full Moon also known as a Super Moon. Seen from Punta Piedras, Argentina and the mouth of the Rio de La Plata, near Buenos Aires, the Super Moon's light created this magnificent circular lunar halo. Still, the size of a lunar halo is determined by the geometry of six sided water ice crystals in planet Earth's high, thin clouds. The crystals deflect the rays of moonlight more strongly through a minimum angle of 22 degrees. So this halo has an inner radius of 22 degrees, just like the halos of the less-than-super moons. Even more common than a Super Moon, beautiful 22 degree halos can be spotted at any time of year. June 27, 2013  This panoramic night scene from June 8 looks out across a Moscow skyline from atop the main building of Lomonosov Moscow State University. Shining in the darkened sky above are widespread noctilucent clouds. From the edge of space, about 80 kilometers above Earth's surface, the icy clouds can still reflect sunlight even though the Sun itself is below the horizon as seen from the ground. Usually spotted at high latitudes in summer months the diaphanous apparitions, also known as polar mesospheric clouds, have come early this season. The seasonal clouds are understood to form as water vapor driven into the cold upper atmosphere condenses on the fine dust particles supplied by meteor smoke (debris left by disintegrating meteors) or volcanic ash. Their early start this year may be connected to changing global circulation patterns in the lower atmosphere. During this northern summer, NASA's AIM mission provides daily projections of the noctilucent clouds as seen from space. June 26, 2013  Andromeda is the nearest major galaxy to our own Milky Way Galaxy. Our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it. The several distinct stars that surround Andromeda's image are actually stars in our Galaxy that are well in front of the background object. Andromeda is frequently referred to as M31 since it is the 31st object on Messier's list of diffuse sky objects. M31 is so distant it takes about two million years for light to reach us from there. Although visible without aid, the above image of M31 was taken with a small telescope. Much about M31 remains unknown, including how it acquired its unusual double-peaked center. June 25, 2013  This is Mars - have a look around. More specifically, this is one area picked for its promise of holding clues to the habitability of Mars to ancient life. To better search for telling leads, the robotic Curiosity rover took a series of detailed images from a location called Rock Nest. Over 900 of these images were then composed into one of the highest resolution images ever created of the red planet - a composite containing over one billion pixels. Shown above, toward the middle of this image mosaic, is Mt. Sharp, the central peak of the large crater where the Curiosity rover landed and is currently exploring. An interactive and zoomable version of this image is available here. Over the next few years, Curiosity is scheduled to roll toward the peak of ancient Mt. Sharp, all the while keeping a lookout for distinguishing geological and chemical markers. June 24, 2013  What's happening to this spiral galaxy? Just a few hundred million years ago, NGC 2936, the upper of the two large galaxies shown, was likely a normal spiral galaxy - spinning, creating stars - and minding its own business. But then it got too close to the massive elliptical galaxy NGC 2937 below and took a dive. Dubbed the Porpoise Galaxy for its iconic shape, NGC 2936 is not only being deflected but also being distorted by the close gravitational interaction. A burst of young blue stars forms the nose of the porpoise toward the left of the upper galaxy, while the center of the spiral appears as an eye. Alternatively, the galaxy pair, together known as Arp 142, look to some like a penguin protecting an egg. Either way, intricate dark dust lanes and bright blue star streams trail the troubled galaxy to the lower right. The above recently-released image showing Arp 142 in unprecedented detail was taken by the Hubble Space Telescope last year. Arp 142 lies about 300 million light years away toward the constellation, coincidently, of the Water Snake (Hydra). In a billion years or so the two galaxies will likely merge into one larger galaxy. June 23, 2013  If you could look across Venus with radar eyes, what might you see? This computer reconstruction of the surface of Venus was created from data from the Magellan spacecraft. Magellan orbited Venus and used radar to map our neighboring planet's surface between 1990 and 1994. Magellan found many interesting surface features, including the large circular domes, typically 25-kilometers across, that are depicted above. Volcanism is thought to have created the domes, although the precise mechanism remains unknown. Venus' surface is so hot and hostile that no surface probe has lasted more than a few minutes. June 22, 2013  As of today, our Sun begins its southern movement as a result we will experience shorter days. In the Netherlands, the duration of the day is now 16 hours and 45 minutes. With an empty beercan, many visitors of the Philippus Lansbergen Observatory in Middelburg, the Netherlands, captured the movement of the Sun with a single six month long exposure. The first solargraphs have been revealed, and this is the result of the sun's movement over the course of six months. This photo was taken by Jan Koeman. Missing sections represent cloudy ovvercast days. The general view that the Netherlands is often cloudy seems to be incorrect in the past six months as there is a large amount of sunlight present in the photo. June 21, 2013  Today, the solstice is at 05:04 Universal Time, the Sun reaching the northernmost declination in its yearly journey through planet Earth's sky. A June solstice marks the astronomical beginning of summer in the northern hemisphere and winter in the south. It also brings the north's longest day, the longest period between sunrise and sunset. This composite image follows the Sun's path toward the end of the June solstice day of 2012 as it approaches the western horizon in a colorful, clear sky. The scene looks north and west along the Tyrrhenian Sea coast from Santa Severa, Italy. Appearing in the well-timed sequence, the small figure of the photographer himself is illuminated against the wall of the town's medieval castle. June 20, 2013  Sharp telescopic views of magnificent edge-on spiral galaxy NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this deep galactic portrait puts some astronomers in mind of its popular moniker, The Hamburger Galaxy. The tantalizing island universe is about 100,000 light-years across and 35 million light-years away in the northern springtime constellation Leo. NGC 3628 shares its neighborhood in the local Universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet. Gravitational interactions with its cosmic neighbors are likely responsible for the extended flare and warp of this spiral's disk. June 19, 2013   How many different astronomical phenomena have come together to create the above vista? Several. First, in the foreground, is Crater Lake - a caldera created by volcanism on planet Earth about 7,700 years ago. Next, inside the lake, is water. Although the origin of the water in the crater is melted snowfall, the origin of water on Earth more generally is unclear, but possibly related to ancient Earthly-impacts of icy bodies. Next, the green glow in the sky is airglow, light emitted by atoms high in the Earth's atmosphere as they recombine at night after being separated during the day by energetic sunlight. The many points of light in the sky are stars, glowing by nuclear fusion. They are far above the atmosphere but nearby to our Sun in the Milky Way Galaxy. Finally, the bright arch across the image is the central band of the Milky Way, much further away, on the average, than the nearby stars, and shaped mostly by gravity. Contrary to appearances, the Milky Way band glows by itself and is not illuminated by the airglow. The above image is a six-frame panorama taken during about two weeks ago in Oregon, USA. June 18, 2013  Consider it a solar eclipse ... of Jupiter. On June 19th the sun will pass directly in front of Jupiter, completely eclipsing the giant planet. Coronagraphs onboard the Solar and Heliospheric Observatory are monitoring the convergence. The CME in the movie was blasted into space by a farside active region described in today's lead news item. Jupiter appears to be in the line of fire, but it is not. The cloud is merely passing in front of the planet; even the CMEs are eclipsing Jupiter today. Updated images of the "eclipse" may be found at the SOHO Realtime Images web page. http://sohowww.nascom.nasa.gov/data/...me-images.html June 17, 2013  What creates these long and nearly straight grooves on Mars? Dubbed linear gullies, they appear on the sides of some sandy slopes during Martian spring, have nearly constant width, extend for as long as two kilometers, and have raised banks along their sides. Unlike most water flows, they do not appear to have areas of dried debris at the downhill end. A leading hypothesis - actually being tested here on Earth - is that these linear gullies are caused by chunks of carbon dioxide ice (dry ice) breaking off and sliding down hills while sublimating into gas, eventually completely evaporating into thin air. The above recently-released image was taken in 2006 by the HiRISE camera on board the NASA's Mars Reconnaissance Orbiter currently orbiting Mars. June 16, 2013  Taken by Maximilian Teodorescu on June 15, 2013 @ Dumitrana (Ilfov), Romania, using a SW Mak 150mm (F/12), Canon 550D, ISO 800, 1/1250s. The Moon is waxing full this week, which means there's more bright territory for spaceships to cross. Yesterday, astrophotographer Maximilian Teodorescu of Dumitrana, Romania, caught the International Space Station passing in front of the Moon in broad daylight. "In the past I have captured the silhouette of the ISS in front of the Sun or Moon," says Teodorescu. But this time the ISS was not silhouetted. It was even more brightly lit than the Moon behind it. "I photographed them both in plain daylight, with the Sun still hanging at 26 degrees above the horizon." Travelling at 17,000 mph, the ISS flits across the face of the Moon in only a fraction of a second. Teodorescu knew when to activate his Canon 550D digital camera using precise transit predictions from CalSky. June 15, 2013  Over a five hour period last Tuesday morning, exposures captured this tantalizing view of meteor streaks and the Milky Way in dark skies above Las Campanas Observatory in Chile. During that time, astronomers had hoped to see an outburst from the gamma Delphinid meteor shower as Earth swept through the dust trail left by an unknown comet. Named for the shower's radiant point in the constellation Delphinus, a brief but strong outburst was reported in bright, moonlit skies on June 10, 1930. While no strong Delphinid meteor activity was reported since, an outburst was tentatively predicted to occur again in 2013. But even though Tuesday's skies were dark, the overall rate of meteors in this field is low, and only the three lower meteor streaks seem to point back to the shower's estimated radiant. June 14, 2013  Sharpless 115 stands just north and west of Deneb, the alpha star of Cygnus the Swan in planet Earth's skies. Noted in the 1959 catalog by astronomer Stewart Sharpless (as Sh2-115) the faint but lovely emission nebula lies along the edge one of the outer Milky Way's giant molecular clouds, about 7,500 light-years away. Shining with the light of ionized atoms of hydrogen, sulfur, and oxygen in this Hubble palette color composite image, the nebular glow is powered by hot stars in star cluster Berkeley 90. The cluster stars are likely only 100 million years old or so and are still embedded in Sharpless 115. But the stars' strong winds and radiation have cleared away much of their dusty, natal cloud. At the emission nebula's estimated distance, this cosmic close-up spans just under 100 light-years. June 13, 2013  You can see four planets in this serene sunset image, created from a series of stacked digital exposures captured near dusk on May 25. The composite picture follows the trail of three of them, Jupiter, Venus, and Mercury (left to right) dropping toward the western horizon, gathered close in last month's remarkable triple planetary conjunction. Similar in brightness to planet Mercury, the star Elnath (Beta Tauri) is also tracked across the scene, leaving its dotted trail still farther to the right. Of course, in the foreground are the still, shallow waters of Alikes salt lake, reflecting the striking colors of sunset over Kos Island, Greece, planet Earth. For now, Jupiter has wandered into the glare of the setting Sun, but Mercury and Venus remain low in the west at twilight. June 12, 2013 For the first time, the entire surface of planet Mercury has been mapped. Detailed observations of the innermost planet's surprising crust have been ongoing since the robotic MESSENGER spacecraft first passed Mercury in 2008 and began orbiting in 2011. Previously, much of the Mercury's surface was unknown as it is too far for Earth-bound telescopes to see clearly, while the Mariner 10 flybys in the 1970s observed only about half. The above video is a compilation of thousands of images of Mercury rendered in exaggerated colors to better contrast different surface features. Visible on the rotating world are rays emanating from a northern impact that stretch across much of the planet, while about half-way through the video the light colored Caloris Basin rotates into view, a northern ancient impact feature that filled with lava. MESSENGER has now successfully completed its primary and first extended missions. June 11, 2013  What's happening in the NGC 3582 nebula? Bright stars and interesting molecules are forming. The complex nebula resides in the star forming region called RCW 57. Visible in this image are dense knots of dark interstellar dust, bright stars that have formed in the past few million years, fields of glowing hydrogen gas ionized by these stars, and great loops of gas expelled by dying stars. A detailed study of NGC 3582, also known as NGC 3584 and NGC 3576, uncovered at least 33 massive stars in the end stages of formation, and the clear presence of the complex carbon molecules known as polycyclic aromatic hydrocarbons (PAHs). PAHs are thought to be created in the cooling gas of star forming regions, and their development in the Sun's formation nebula five billion years ago may have been an important step in the development of life on Earth. The above image was taken at the Desert Hollow Observatory north of Phoenix, Arizona, USA. June 10, 2013   Where are the hottest stars in the nearest galaxies? To help find out, NASA commissioned its Earth-orbiting Swift satellite to compile a multi-image mosaic of the neighboring Large Magellanic Cloud (LMC) galaxy in ultraviolet light. The above image shows where recently formed stars occur in the LMC, as the most massive of these young stars shine brightly in blue and ultraviolet. In contrast, a more familiar view of the LMC in visible light better highlights older stars. On the upper left is one of the largest star forming regions known in the entire Local Group of galaxies: the Tarantula Nebula. The Large Magellanic Cloud and its smaller companion the Small Magellanic Cloud are easily visible with the unaided eye to sky enthusiasts with a view of the southern sky. Detailed inspection of the above image is allowing a better galaxy-comprehensive picture for how star formation occurs. June 9, 2013 On the afternoon of June 5th, the European Space Agency launched a robotic spaceship named "Albert Einstein" into Earth orbit. Also known as "ATV-4" (Automated Transfer Vehicle 4), the Albert Einstein is a cargo carrier laden with supplies for the International Space Station. Marco Langbroek saw it flying over Leiden, the Netherlands, just two hours after launch: "The ATV-4 was very bright (mag +1 to +0.5) and easily visible to the naked eye, even from Leiden center," Langbroek. "Still in a low orbit, it was very fast." To resupply the space station, the Albert Einstein is carrying the most dry cargo ever launched by a European spacecraft - 2,480 kilograms, and the most diverse cargo mix - 1400 different items. It will catch up to and dock with the ISS on June 15th. As that date approaches, the ATV-4 and the ISS will become visible in the night sky at the same time. June 8, 2013  Many bright nebulae and star clusters in planet Earth's sky are associated with the name of astronomer Charles Messier, from his famous 18th century catalog. His name is also given to these two large and remarkable craters on the Moon. Standouts in the dark, smooth lunar Sea of Fertility or Mare Fecunditatis, Messier (left) and Messier A have dimensions of 15 by 8 and 16 by 11 kilometers respectively. Their elongated shapes are explained by an extremely shallow-angle trajectory followed by the impactor, moving left to right, that gouged out the craters. The shallow impact also resulted in two bright rays of material extending along the surface to the right, beyond the picture. Intended to be viewed with red/blue glasses (red for the left eye), this striking stereo picture of the crater pair was recently created from high resolution scans of two images (AS11-42-6304, AS11-42-6305) taken during the Apollo 11 mission to the moon. 
June 7, 2013  The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects. Though its wingspan covers over 3 light-years, NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the dying central star of this particular planetary nebula has become exceptionally hot, shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. This sharp and colorful close-up of the dying star's nebula was recorded in 2009 by the Hubble Space Telescope's Wide Field Camera 3, installed during the final shuttle servicing mission. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius). June 6, 2013  Although you've surely seen it, you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly off-color, slightly pink. Called the Belt of Venus, this off-color band between the dark eclipsed sky and the blue sky can be seen in nearly every direction including that opposite the Sun. Straight above, blue sky is normal sunlight reflecting off the atmosphere. In the Belt of Venus, however, the atmosphere reflects light from the setting (or rising) Sun which appears more red. The Belt of Venus can be seen from any location with a clear horizon. Pictured above, the Belt of Venus was photographed above morning fog in the Valley of the Moon, a famous wine-producing region in northern California, USA. The belt is frequently caught by accident in other photographs. June 5, 2013  Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. Its classic appearance is understood to be due to our own perspective, though. The recent mapping of the expanding nebula's 3-D structure, based in part on this clear Hubble image, indicates that the nebula is a relatively dense, donut-like ring wrapped around the middle of a football-shaped cloud of glowing gas. The view from planet Earth looks down the long axis of the football, face-on to the ring. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from the dying, once sun-like star, now a tiny pinprick of light seen at the nebula's center. Intense ultraviolet light from the hot central star ionizes atoms in the gas. In the picture, the blue color in the center is ionized helium, the cyan color of the inner ring is the glow of hydrogen and oxygen, and the reddish color of the outer ring is from nitrogen and sulfur. The Ring Nebula is about one light-year across and 2,000 light-years away. June 4, 2013  Few astronomical sights excite the imagination like the nearby stellar nursery known as the Orion Nebula. The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud. Many of the filamentary structures visible in the above image are actually shock waves - fronts where fast moving material encounters slow moving gas. The Orion Nebula spans about 40 light years and is located about 1500 light years away in the same spiral arm of our Galaxy as the Sun. The Great Nebula in Orion can be found with the unaided eye just below and to the left of the easily identifiable belt of three stars in the popular constellation Orion. The above image shows the nebula in three colors specifically emitted by hydrogen, oxygen, and sulfur gas. The whole Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next 100,000 years. June 3, 2013  Could life ever have existed on Mars? To help find out, humanity landed the Curiosity rover on Mars last August. To make sure the car-sized explorer survived the interplanetary trip and dramatic landing intact, the above image and others was taken peering at, under, and around Curiosity. Pictured above in this unusual vista are three of Curiosity's six wheels, each measuring about half a meter across. In recent months, Curiosity has been exploring the surroundings of an area dubbed Yellowknife Bay. Analyses of data taken by Curiosity's cameras and onboard laboratories has provided strong new evidence that Mars could once have supported life. In the distance is part of the slope to the central peak inside Gale Crater that Curiosity is scheduled to attempt to climb - Mt. Sharp. June 2, 2013  What kind of cloud is this? A roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud. When this happens uniformly along an extended front, a roll cloud may form. Roll clouds may actually have air circulating along the long horizontal axis of the cloud. A roll cloud is not thought to be able to morph into a tornado. Unlike a similar shelf cloud, a roll cloud, a type of Arcus cloud, is completely detached from their parent cumulonimbus cloud. Pictured above, a roll cloud extends far into the distance in 2009 January above Las Olas Beach in Maldonado, Uruguay. June 1, 2013  Last night, a powerful interplanetary shockwave from the sun slammed the planet and resulted in a G2-class (Kp=6) geomagnetic storm. The storm as of this post still has not let up, but at its peak from last night, it was easily visible as far south as Colorado, Maryland, Iowa, Wisconsin, and Nebraska. High-latitude sky watchers should remain alert for auroras tonight as Earth's magnetic field continues to reverberate from the impact. Today's photograph was taken by Bob Conzemius on June 1, 2013 at Grand Rapids, MN, USA. The powerful green auroras were luminescent enough to penetrate through a thin layer of clouds and create an eerie green skyscape, complemented by the yellow lights of nearby towns. ISO 800, f2.8, 25 sec., 24mm, looking east along the cloud-obscured oval was the specifications for this photo. May 31, 2013  As planet Earth approached the plane of the Comet PanSTARRS (C/2011 L4) orbit on May 23rd, comet watchers were treated to this view of its magnificent anti-tail. The long, narrow anti-tail stretches to the right across this frame for nearly 7 degrees or about 14 times the angular size of the full Moon. Dust forming the anti-tail trails along the comet's orbit as it leaves the inner solar system behind. An almost edge-on perspective from near the outbound comet's orbital plane enhances the view of the anti-tail and makes it seem to point in the sunward direction, only apparently contrary to the behavior of comet dust tails pushed outward by the pressure of sunlight. Sweeping far north in planet Earth's skies, the comet is up all night for most of the northern hemisphere, but now bright moonlight interferes with its visibility. PanSTARRS anti-tail is one of the longest since the appearance of Comet Arend-Roland in 1957. May 30, 2013   The 16th century Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two fuzzy cloud-like objects easily visible to southern hemisphere skygazers are known as the Clouds of Magellan, now understood to be satellite galaxies of our much larger, spiral Milky Way galaxy. About 160,000 light-years distant in the constellation Dorado, the Large Magellanic Cloud (LMC) is seen here in a remarkably deep, colorful, and annotated composite image. Spanning about 15,000 light-years or so, it is the most massive of the Milky Way's satellite galaxies and is the home of the closest supernova in modern times, SN 1987A. The prominent patch just left of center is 30 Doradus, also known as the magnificent Tarantula Nebula, is a giant star-forming region about 1,000 light-years across. May 29, 2013  How bright is nebulosity in Algonquin Park? The answer is its about as bright as it ever gets from the vantage point of this planet. Today's picture is a shot of a pair of nebulae that to my eyes only appeared to be dark fuzzy patches in the sky - I wasn't originally targetting the pair that can be found at the top and bottom of the image but rather I happened to point my camera in this direction while making a larger panorama sized picture. The human eye can't see more than visible light, so many of the nebulae will appear as gray patches. The other reason for this is that they are simply too faint to show colour as well, but a decent camera today will be able to pick them up. A nebula that comes out as a fluorescent violet is likely to have more colour spectra with a wavelength shorter than that of the violet colour spectrum. For this particular nebula, if you had a filter that blocked out all light except ultra Violet, you'd actually get a better picture than one that allows visible light! The following picture highlights the striking difference between infrared, visible and UV filters. Note how the colours of the orion nebula are more vibrant in UV, however the flame nebula near the top left of the image appears invisible in UV - This is because the flame nebula is orange-reddish in colour and is nowhere near the UV spectrum.  May 28, 2013  What does the Andromeda Galaxy look like in a sky with no light pollution? M31 is almost impossible to spot in a city or large town, and to the untrained eye can also be difficult when a bright moon fills the sky. However when there's no moon lighting up the sky, you may begin to notice a sizeable fuzzy patch in the constellation of Andromeda, just beside Perseus. This fuzzy patch is the Andromeda Galaxy. It's approximately 2.5 million light years from Earth, however that number will shrink in time. M31 is on a collision course with the Milky Way that will lead to a head on collision in about 2 billion years. While this sounds violent, it is unlikely in this collision that any stars will actually crash into each other. Familiar stars however, will be thrown out of their current position and hurled to various new spots of the galaxy. May 27, 2013  On May 26, 2013, Mercury, Venus and Jupiter formed a very tight triangle, just 2½° wide. The triple conjunction itself is set to last for a span of a couple weeks where all three planets fit inside a 5° circle, but yesterday was the day where all three were closest together. Venus and Mercury, the two right planets in this image, appear their closest together tomorrow May 28. This image was taken atop Leaside Bridge in Toronto, with a hydrofield in the distance. Jupiter continues to sink lower into the horizon while Venus and Mercury make their way higher into better seeing conditions. Mercury is the fastest changing of the three planets, largely because its year is only 88 days and it does not take very long to revolve around the sun. If you follow Mercury long enough, you will begin to see Mercury arc back downward toward the horizon as it heads for another revolution around the sun. May 26, 2013  If you are in a dark location and you are willing to stay up to roughly midnight at this time of year, you have the luxury to step outside on a clear night and enjoy the rise of the milky way - the galaxy that rests in our backyard. Scorpius is the constellation that appears to pull the galactic centre with Antares being the dominant red star in the middle of the constellation. Ophiuchus sits on top of this image above Scorpius, and the Sagittarius Teapot sits above the treeline. Multiple messier objects appear in this image as well including the Trifid and Lagoon nebula. May 25, 2013  So far, Sunspot AR1748 has produced more X-flares than every other sunspot of the past year combined. AR1748 has produced more X-flares than every other sunspot of the past year combined. In summary, AR1748 has given us an X1.7-class flare (0217 UT on May 13), an X2.8-class flare (1609 UT on May 13), an X3.2-class flare (0117 UT on May 14), and an X1-class flare (0152 on May 15). The last of these flares was hurled towards Earth and is the reason I was able to capture the massive geomagnetic storm that occurred over the weekend. While green is the most dominant colour of auroras, with stronger storms you're just as likely to find fainter, purple-blue-red colours as well. Today's picture highlights just how bright and elevated the Northern Lights can get even as low as 45.5842° N. In this picture, the auroras fill over 15° of the northern sky in a spectacular array of colours. While pretty to look at, it's also a reminder that the Earth is constantly bombarded by harmful rays of the sun and a very thin layer is all the planet has to protect those rays from entering the planet and disrupting electronics. May 24, 2013  The Lake of Two Rivers in Algonquin Park was the benefactor of a large geomagnetic storm for those who were willing to look up. The storm came from an x-class solar flare that ejected out of the sun towards Earth on May 15th. At times, the auroras were luminescent enough to be seen inside cars. The auroras for the most part lasted the entire night and continued into the morning hours after sunrise - though by then, they were no longer visible. Purple auroras can be easily seen in this picture. Purple, Blue, Red and green are common colours of auroras where green is the lowest altitude, followed by purple, blue, and then red. May 23, 2013  This scene is found on the west beach on the Lake of Two Rivers in Algonquin Park. A canoe marks the foreground of the lake which has been cast an eerie green glow due to the northern lights roaming around in the distance. Also, a car drove by on the nearby highway whose headlights illuminated the midnight forest to create an intresting depth of field. There was no wind this night, and the water was perfectly still. It acted as if it was a mirror into the sky. The Northern Lights were caused by a geomagnetic storm that hit the earth May 17, 2013 due to an x-class flare that launched from the sun on May 15. May 22, 2013  Your cosmic tea is ready, straight from the celestial teapot with a dash of milk from our local milky way. Enjoy - it's out of this world! This stellar scene is just one of many that laid before me during my trek to Algonquin Park. The teapot of Sagittarius is easily visible, which appears to dip ever so slightly into the Sagittarius cloud, one of the brightest bands of the galactic core that we can see. The Trifid nebula is easily visible to the upper right of the Teapot. May 21, 2013 [img]http://apod.nasa.gov/apod/image/1305/panstarrs15may2013-mfulle_1368632878_1000.jpg]/img] Once the famous sunset comet, PanSTARRS (C/2011 L4) is now visible all night from much of the northern hemisphere, bound for the outer solar system as it climbs high above the ecliptic plane. Dimmer and fading, the comet's broad dust tail is still growing, though. This widefield telescopic image was taken against the starry background of the constellation Cepheus on May 15. It shows the comet has developed an extensive anti-tail, dust trailing along the comet's orbit (to the left of the coma), stretching more than 3 degrees across the frame. Since the comet is just over 1.6 astronomical units from planet Earth, that corresponds to a distance of over 12 million kilometers. In late May Comet PanSTARRS will pass within a few degrees of the north celestial pole. May 20, 2013  One of the brightest galaxies in planet Earth's sky and similar in size to the Milky Way, big, beautiful spiral M81 lies 11.8 million light-years away in the northern constellation Ursa Major. This deep image of the region reveals details in the bright yellow core, but at the same time follows fainter features along the galaxy's gorgeous blue spiral arms and sweeping dust lanes. It also follows the expansive, arcing feature, known as Arp's loop, that seems to rise from the galaxy's disk at the right. Studied in the 1960s, Arp's loop has been thought to be a tidal tail, material pulled out of M81 by gravitational interaction with its large neighboring galaxy M82. But a recent investigation demonstrates that much of Arp's loop likely lies within our own galaxy. The loop's colors in visible and infrared light match the colors of pervasive clouds of dust, relatively unexplored galactic cirrus only a few hundred light-years above the plane of the Milky Way. Along with the Milky Way's stars, the dust clouds lie in the foreground of this remarkable view. M81's dwarf companion galaxy, Holmberg IX, can be seen just above and left of the large spiral. On the sky, this image spans about 0.5 degrees, about the size of the Full Moon. May 19, 2013  Scroll right to take in the view from the highest summit in the contiguous USA. The above 360-degree digitally stitched panorama, taken in mid-July, shows the view from 4,400-meter high Mt. Whitney in Sequoia National Park, California. In the foreground, angular boulders populate Mt. Whitney's summit while in the distance, just below the horizon, peaks from the Sierra Nevada mountain range are visible. Sky sights include light pollution emanating from Los Angeles and Fresno, visible just above the horizon. Dark clouds, particularly evident on the image left well above the horizon, are the remnants of a recent thunderstorm near Death Valley. High above, the band of the Milky Way Galaxy arches across the image left. Bright airglow bands are visible all over the sky but are particularly prominent on the image right. The planet Jupiter appears as the brightest point on the image left. A discerning eye can also find a faint image of the far distant Andromeda galaxy, a satellite trail, and many constellations. May 18, 2013  The Parkes 64 meter radio telescope is known for its contribution to human spaceflight, famously supplying television images from the Moon to denizens of planet Earth during Apollo 11. The enormous, steerable, single dish looms in the foreground of this early evening skyscape. Above it, the starry skies of New South Wales, Australia include familiar southerly constellations Vela, Puppis, and Hydra along with a sight that will never be seen again. Still glinting in sunlight and streaking right to left just below the radio telescope's focus cabin, the space shuttle orbiter Atlantis has just undocked with the International Space Station for the final time. The space station itself follows arcing from the lower right corner of the frame, about two minutes behind Atlantis in low Earth orbit. Atlantis made its final landing early July 21, 5:57am EDT at NASA's Kennedy Space Center. May 17, 2013  Above this boreal landscape, the arc of the Milky Way and shimmering aurorae flow through the night. Like an echo, below them lies Iceland's spectacular Godafoss, the Waterfall of the Gods. Shining just below the Milky Way, bright Jupiter is included in the panoramic nightscape recorded on March 9. Faint and diffuse, the Andromeda Galaxy (M31) appears immersed in the auroral glow. The digital stitch of four frames is a first place winner in the 2013 International Earth and Sky Photo Contest on Dark Skies Importance organized by The World at Night. An evocative record of the beauty of planet Earth's night sky, all the contest's winning entries are featured in this video. http://vimeo.com/41781867 May 16, 2013  Swinging around the Sun's eastern limb on Monday, a group of sunspots labeled active region AR1748 has produced the first four X-class solar flares of 2013 in less than 48 hours. In time sequence clockwise from the top left, flashes from the four were captured in extreme ultraviolet images from the Solar Dynamics Observatory. Ranked according to their peak brightness in X-rays, X-class flares are the most powerful class and are frequently accompanied by coronal mass ejections (CMEs), massive clouds of high energy plasma launched into space. But CMEs from the first three flares were not Earth-directed, while one associated with the fourth flare may deliver a glancing blow to the Earth's magnetic field on May 18. Also causing temporary radio blackouts, AR1748 is likely not finished. Still forecast to have a significant chance of producing strong flares, the active region is rotating into more direct view across the Sun's nearside. May 15, 2013  What caused this mess? Some type of star exploded to create the unusually shaped nebula known as Kepler's supernova remnant, but which type? Light from the stellar explosion that created this energized cosmic cloud was first seen on planet Earth in October 1604, a mere four hundred years ago. The supernova produced a bright new star in early 17th century skies within the constellation Ophiuchus. It was studied by astronomer Johannes Kepler and his contemporaries, without the benefit of a telescope, as they searched for an explanation of the heavenly apparition. Armed with a modern understanding of stellar evolution, early 21st century astronomers continue to explore the expanding debris cloud, but can now use orbiting space telescopes to survey Kepler's supernova remnant (SNR) across the spectrum. Recent X-ray data and images of Kepler's supernova remnant taken by the orbiting Chandra X-ray Observatory has shown relative elemental abundances typical of a Type Ia supernova, and further indicated that the progenitor was a white dwarf star that exploded when it accreted too much material from a companion Red Giant star and went over Chandrasekhar's limit. About 13,000 light years away, Kepler's supernova represents the most recent stellar explosion seen to occur within our Milky Way galaxy. May 14, 2013 What happens when two galaxies collide? Although it may take over a billion years, such titanic clashes are quite common. Since galaxies are mostly empty space, no internal stars are likely to themselves collide. Rather the gravitation of each galaxy will distort or destroy the other galaxy, and the galaxies may eventually merge to form a single larger galaxy. Expansive das and dust clouds collide and trigger waves of star formation that complete even during the interaction process. Pictured above is a computer simulation of two large spiral galaxies colliding, interspersed with real still images taken by the Hubble Space Telescope. Our own Milky Way Galaxy has absorbed several smaller galaxies during its existence and is even projected to merge with the larger neighboring Andromeda galaxy in a few billion years. May 13, 2013  It was just eight minutes after sunrise, last week, and already there were four things in front of the Sun. The largest and most notable was Earth's Moon, obscuring a big chunk of the Sun's lower limb as it moved across the solar disk, as viewed from Fremantle, Australia. This was expected as the image was taken during a partial solar eclipse - an eclipse that left sunlight streaming around all sides of the Moon from some locations. Next, a band of clouds divided the Sun horizontally while showing interesting internal structure vertically. The third intervening body might be considered to be the Earth's atmosphere, as it dimmed the Sun from its higher altitude brightness while density fluctuations caused the Sun's edges to appear to shimmer. Although closest to the photographer, the least expected solar occulter was an airplane. Quite possibly, passengers on both sides of that airplane were contemplating the unusual view only visible out the eastern-facing windows. May 12, 2013  Sometimes the sky above can become quite a show. In early September of 2010, for example, the Moon and Venus converged, creating quite a sight by itself for sky enthusiasts around the globe. From some locations, though, the sky was even more picturesque. In the above image taken last week from Spain, a crescent Moon and the planet Venus, on the far right, were captured during sunset posing against a deep blue sky. In the foreground, dark storm clouds loom across the image bottom, while a white anvil cloud shape appears above. Black specks dot the frame, caused by a flock of birds taking flight. Very soon after this picture was taken, however, the birds passed by, the storm ended, and Venus and the Moon set. Bright Venus again becomes visible just after sunset this 2013 May and will appear near Jupiter toward the end of the month. May 11, 2013  This week the shadow of the New Moon fell on planet Earth, crossing Queensland's Cape York in northern Australia ... for the second time in six months. On the morning of May 10, the Moon's apparent size was too small to completely cover the Sun though, revealing a "ring of fire" along the central path of the annular solar eclipse. Near mid-eclipse from Coen, Australia, a webcast team captured this telescopic snapshot of the annular phase. Taken with a hydrogen-alpha filter, the dramatic image finds the Moon's silhouette just within the solar disk, and the limb of the active Sun spiked with solar prominences. Still, after hosting back-to-back solar eclipses, northern Australia will miss the next and final solar eclipse of 2013. This November, a rare hybrid eclipse will track across the North Atlantic and equatorial Africa. May 10, 2013  Face-on spiral galaxy M77 lies a mere 47 million light-years away toward the aquatic constellation Cetus. At that estimated distance, the gorgeous island universe is about 100 thousand light-years across. Also known as NGC 1068, its compact and very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active Seyfert galaxies. M77 is also seen at x-ray, ultraviolet, infrared, and radio wavelengths. But this sharp visible light image based on Hubble data follows its winding spiral arms traced by obscuring dust clouds and red-tinted star forming regions close in to the galaxy's luminous core. May 9, 2013  As the New Moon continues this season's celestial shadow play, an annular solar eclipse track begins in western Australia at 22:30 UT on May 9 - near sunrise on May 10 local time. Because the eclipse occurs within a few days of lunar apogee, the Moon's silhouette does not quite cover the Sun during mid-eclipse, momentarily creating a spectacular ring of fire. While a larger region witnesses a partial eclipse, the annular mid-eclipse phase is visible along a shadow track only about 200 kilometers wide but 13,000 kilometers long, extending across the central Pacific. For given locations along it, the ring of fire lasts from 4 to 6 minutes. Near the horizon, the appearance of the May 9/10 annular eclipse (online viewing) is suggested by this dramatic composite from May of 2012. The timelapse sequence depicts an annular eclipse in progress before sunset over Monument Valley in the southwestern United States. May 8, 2013  A tremendous explosion has occurred in the nearby universe and major telescopes across Earth and space are investigating. Dubbed GRB 130427A, the gamma-ray burst was first detected by the Earth-orbiting Fermi and Swift satellites observing at high energies and quickly reported down to Earth. Within three minutes, the half-meter ISON telescope in New Mexico found the blast in visible light, noted its extreme brightness, and relayed more exact coordinates. Within the next few minutes, the bright optical counterpart was being tracked by several quickly re-pointable telescopes including the 2.0-meter P60 telescope in California, the 1.3-meter PAIRITEL telescope in Arizona, and the 2.0-meter Faulkes Telescope North in Hawaii. Within two hours, the 8.2-meter Gemini North telescope in Hawaii noted a redshift of 0.34, placing the explosion about 5 billion light years away - considered nearby in cosmological terms. Previously recorded images from the RAPTOR full-sky monitors were scanned and a very bright optical counterpart - magnitude 7.4 - was found 50 seconds before the Swift trigger. The brightest burst in recent years, a signal from GRB 130427A has also been found in low energy radio waves by the Very Large Array (VLA) and at the highest energies ever recorded by the Fermi satellite. Neutrino, gravitational wave, and telescopes designed to detect only extremely high energy photons are checking their data for a GRB 130427A signal. Pictured in the above animation, the entire gamma-ray sky is shown becoming momentarily dominated by the intense glow of GRB 130427A. Continued tracking the optical counterpart will surely be ongoing as there is a possibility that the glow of a classic supernova will soon emerge. May 7, 2013  To see a vista like this takes patience, hiking, and a camera. Patience was needed in searching out just the right place and waiting for just the right time. A short hike was needed to reach this rugged perch above a secluded cove in Julia Pfeiffer Burns State Park in California, USA. And a camera was needed for the long exposure required to bring out the faint light from stars and nebula in the background Milky Way galaxy. Moonlight and a brief artificial flash illuminated the hidden beach and inlet behind nearby trees in the above composite image taken about two weeks ago. Usually obscured McWay Falls is visible just below the image center, while the Pacific Ocean is in view to its right. May 6, 2013  What caused the interestingly intricate tails that Comet Lemmon displayed earlier this year? First of all, just about every comet that nears the Sun displays two tails: a dust tail and an ion tail. Comet Lemmon's dust tail, visible above and around the comet nucleus in off-white, is produced by sun-light reflecting dust shed by the comet's heated nucleus. Flowing and more sculptured, however, is C/2012 F6 (Lemmon)'s blue ion tail, created by the solar wind pushing ions expelled by the nucleus away from the Sun. Also of note is the coma seen surrounding Comet Lemmon's nucleus, tinted green by atomic carbon gas fluorescing in sunlight. The above image was taken from the dark skies of Namibia in mid-April. Comet Lemmon is fading as it now heads back to the outer Solar System. May 5, 2013  Is that a spaceship or a cloud? Although it may seem like an alien mothership, it's actually a impressive thunderstorm cloud called a supercell. Such colossal storm systems center on mesocyclones - rotating updrafts that can span several kilometers and deliver torrential rain and high winds including tornadoes. Jagged sculptured clouds adorn the supercell's edge, while wind swept dust and rain dominate the center. A tree waits patiently in the foreground. The above supercell cloud was photographed in July west of Glasgow, Montana, USA, caused minor damage, and lasted several hours before moving on. May 4, 2013  Last week, as the Sun set a Full Moon rose over the springtime landscape of Tihany, Hungary on the northern shores of Lake Balaton. As it climbed into the clear sky, the Moon just grazed the dark, umbral shadow of planet Earth in the year's first partial lunar eclipse. The partial phase, seen near the top of this frame where the lunar disk is darkened along the upper limb, lasted for less than 27 minutes. Composited from consecutive exposures, the picture presents the scene's range of natural colors and subtle shading apparent to the eye. At next week's New Moon, the season's celestial shadow play will continue with an annular solar eclipse, the path of annularity tracking through northern Australia and the central Pacific. May 3, 2013  Combined image data from the massive, ground-based VISTA telescope and the Hubble Space Telescope was used to create this wide perspective of the interstellar landscape surrounding the famous Horsehead Nebula. Captured at near-infrared wavelengths, the region's dusty molecular cloud sprawls across the scene that covers an angle about two-thirds the size of the Full Moon on the sky. Left to right the frame spans just over 10 light-years at the Horsehead's estimated distance of 1,600 light-years. Also known as Barnard 33, the still recognizable Horsehead Nebula stands at the upper right, the near-infrared glow of a dusty pillar topped with newborn stars. Below and left, the bright reflection nebula NGC 2023 is itself the illuminated environs of a hot young star. Dense clouds below the base of the Horsehead and on the outskirts of NGC 2023 show the tell-tale far red emission of energetic jets, known as Herbig-Haro objects, also associated with newborn stars. May 2, 2013  Acquiring its first sunlit views of far northern Saturn late last year, the Cassini spacecraft's narrow-angle camera recorded this stunning image of the vortex at the ringed planet's north pole. The false color, near-infrared image results in red hues for low clouds and green for high ones, causing the north-polar hurricane to take on the appearance of a rose. Enormous by terrestrial hurricane standards, this storm's eye is about 2,000 kilometers wide, with clouds at the outer edge traveling at over 500 kilometers per hour. The north pole Saturn hurricane swirls inside the large, six-sided weather pattern known as the hexagon. Of course, in 2006 Cassini also imaged the hurricane at Saturn's south pole. May 1, 2013  This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy. Of the 200 or so globular clusters that survive today, Omega Centauri is the largest, containing over ten million stars. Omega Centauri is also the brightest globular cluster, at apparent visual magnitude 3.9 it is visible to southern observers with the unaided eye. Cataloged as NGC 5139, Omega Centauri is about 18,000 light-years away and 150 light-years in diameter. Unlike many other globular clusters, the stars in Omega Centauri show several different ages and trace chemical abundances, indicating that the globular star cluster has a complex history over its 12 billion year age. April 30, 2013  What spacecraft is humanity currently using to explore our Solar System? Presently, every inner planet has at least one robotic explorer, while several others are monitoring our Sun, some are mapping Earth's Moon, a few are chasing asteroids and comets, one is orbiting Saturn, and several are even heading out into deep space. The above illustration gives more details, with the inner Solar System depicted on the upper right and the outer Solar System on the lower left. Given the present armada, our current epoch might become known as the time when humanity first probed its own star system. Sometimes widely separated spacecraft act together as an InterPlanetary Network to determine the direction of distant explosions by noting when each probe detects high energy photons. Future spacecraft milestones, as indicated along the bottom of the graphic, include Dawn reaching Ceres, the largest object in the asteroid belt, and New Horizons reaching Pluto, both in 2015. April 29, 2013   What's that next to the Milky Way? An unusual natural rock formation known as Roque Cinchado or Stone Tree found on the Spanish Canary Island of Tenerife. A famous icon, Roque Cinchado is likely a dense plug of cooled volcanic magma that remains after softer surrounding rock eroded away. Majestically, the central band of our Milky Way Galaxy is visible arcing across the right of the above seven image panoramic mosaic taken during the summer of 2010. On the far right is the Teide volcano complete with a lenticular cloud hovering near its peak. April 28, 2013  It was one of the largest and longest lived storms ever recorded in our Solar System. First seen in late 2010, the above cloud formation in the northern hemisphere of Saturn started larger than the Earth and soon spread completely around the planet. The storm was tracked not only from Earth but from up close by the robotic Cassini spacecraft currently orbiting Saturn. Pictured above in false colored infrared in February, orange colors indicate clouds deep in the atmosphere, while light colors highlight clouds higher up. The rings of Saturn are seen nearly edge-on as the thin blue horizontal line. The warped dark bands are the shadows of the rings cast onto the cloud tops by the Sun to the upper left. A source of radio noise from lightning, the intense storm was thought to relate to seasonal changes when spring emerges in the north of Saturn. After raging for over six months, the iconic storm circled the entire planet and then tried to absorb its own tail - which surprisingly caused it to fade away. This set of images from NASA's Cassini mission shows the evolution of a massive thunder-and-lightning storm that circled all the way around Saturn and fizzled when it ran into its own tail. The storm was first detected on Dec. 5, 2010.  April 27, 2013  Get out your red/blue glasses and gaze across the floor of Gale crater on Mars. From your vantage point on the deck of the Curiosity Rover Mount Sharp, the crater's 5 kilometer high central mountain looms over the southern horizon. Poised in the foreground is the rover's robotic arm with tool turret extended toward the flat veined patch of martian surface dubbed "John Klein". A complete version of the stereo view spans 360 degrees, digitally stitched together from the rover's left and right navigation camera frames taken in late January. The layered lower slopes of Mount Sharp, formally known as Aeolis Mons, are a future destination for Curiosity. Find the complete version here: http://photojournal.jpl.nasa.gov/catalog/PIA16925 April 26, 2013  Our solar system's miasma of incandescent plasma, the Sun may look a little scary here. The picture is a composite of 25 images recorded in extreme ultraviolet light by the orbiting Solar Dynamics Observatory between April 16, 2012 and April 15, 2013. The particular wavelength of light, 171 angstroms, shows emission from highly ionized iron atoms in the solar corona at a characteristic temperatures of about 600,000 kelvins (about 1 million degrees F). Girdling both sides of the equator during the approach to maximum in its 11-year solar cycle, the solar active regions are laced with bright loops and arcs along magnetic field lines. Of course, a more familiar visible light view would show the bright active regions as groups of dark sunspots. Three years of Solar Dynamics Observatory images are compressed into this short video. April 25, 2013  The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section and is most easily seen during a lunar eclipse. But the complete cross section is larger than the Moon's angular size in the stages of an eclipse. Still, this thoughtful composite illustrates the full extent of the circular shadow by utilizing images from both partial and total eclipses passing through different parts of the umbra. The images span the years 1997 to 2011, diligently captured with the same optics, from Voronezh, Russia. Along the bottom and top are stages of the partial lunar eclipses from September 2006 and August 2008 respectively. In the rightside bottom image, the Moon is entering the umbra for the total eclipse of September 1997. At left bottom, the Moon leaves the umbra after totality in May 2004. Middle right, center, and left, are stages of the total eclipse of June 2011, including the central, deep red total phase. During today's brief partial lunar eclipse seen only from the eastern hemisphere, the Moon will just slightly graze the umbra's lower edge. April 24, 2013 What happens if you wring out a wet towel while floating in space? The water shouldn't fall toward the floor because while orbiting the Earth, free falling objects will appear to float. But will the water fly out from the towel, or what? The answer may surprise you. To find out and to further exhibit how strange being in orbit can be, Expedition 35 Commander Chris Hadfield did just this experiment last week in the microgravity of the Earth orbiting International Space Station. As demonstrated in the above video, although a few drops do go flying off, most of the water sticks together and forms a unusual-looking cylindrical sheath in and around the towel. The self-sticking surface tension of water is well known on Earth, for example being used to create Artistic Water cascades and, more generally, raindrops. April 23, 2013  What looks like a puff-ball is surely the remains of the brightest supernova in recorded human history. In 1006 AD, it was recorded as lighting up the nighttime skies above areas now known as China, Egypt, Iraq, Italy, Japan, and Switzerland. The expanding debris cloud from the stellar explosion, found in the southerly constellation the Wolf (Lupus), still puts on a cosmic light show across the electromagnetic spectrum. In fact, the above image results from three colors of X-rays taken by the orbiting Chandra X-ray Observatory. Now known as the SN 1006 supernova remnant, the debris cloud appears to be about 60 light-years across and is understood to represent the remains of a white dwarf star. Part of a binary star system, the compact white dwarf gradually captured material from its companion star. The buildup in mass finally triggered a thermonuclear explosion that destroyed the dwarf star. Because the distance to the supernova remnant is about 7,000 light-years, that explosion actually happened 7,000 years before the light reached Earth in 1006. Shockwaves in the remnant accelerate particles to extreme energies and are thought to be a source of the mysterious cosmic rays. April 22, 2013  While drifting through the cosmos, a magnificent interstellar dust cloud became sculpted by stellar winds and radiation to assume a recognizable shape. Fittingly named the Horsehead Nebula, it is embedded in the vast and complex Orion Nebula (M42). A potentially rewarding but difficult object to view personally with a small telescope, the above gorgeously detailed image was recently taken in infrared light by the orbiting Hubble Space Telescope in honor of the 23rd anniversary of Hubble's launch. The dark molecular cloud, roughly 1,500 light years distant, is cataloged as Barnard 33 and is seen above primarily because it is backlit by the nearby massive star Sigma Orionis. The Horsehead Nebula will slowly shift its apparent shape over the next few million years and will eventually be destroyed by the high energy starlight. April 21, 2013   Do you see it? This common question frequently precedes the rediscovery of one of the most commonly recognized configurations of stars on the northern sky: the Big Dipper. This grouping of stars is one of the few things that has likely been seen, and will be seen, by every generation. The Big Dipper is not by itself a constellation. Although part of the constellation of the Great Bear (Ursa Major), the Big Dipper is an asterism that has been known by different names to different societies. Five of the Big Dipper stars are actually near each other in space and were likely formed at nearly the same time. Connecting two stars in the far part of the Big Dipper will lead one to Polaris, the North Star, which is part of the Little Dipper. Relative stellar motions will cause the Big Dipper to slowly change its apparent configuration over the next 100,000 years. April 20, 2013  As far as the eye could see, it was a dark night at Las Campanas Observatory in the southern Atacama desert of Chile. But near local midnight on April 11, this mosaic of 3 minute long exposures revealed a green, unusually intense, atmospheric airglow stretching over thin clouds. Unlike aurorae powered by collisions with energetic charged particles and seen at high latitudes, the airglow is due to chemiluminescence, the production of light in a chemical reaction, and found around the globe. The chemical energy is provided by the Sun's extreme ultraviolet radiation. Like aurorae, the greenish hue of this airglow does originate at altitudes of 100 kilometers or so dominated by emission from excited oxygen atoms. The gegenschein, sunlight reflected by dust along the solar system's ecliptic plane was still visible on that night, a faint bluish cloud just right of picture center. At the far right, the Milky Way seems to rise from the mountain top perch of the Magellan telescopes. Left are the OGLE project and du Pont telescope domes. April 19, 2013  Sculpted by stellar winds and radiation, the star factory known as Messier 17 lies some 5,500 light-years away in the nebula-rich constellation Sagittarius. At that distance, this degree wide field of view spans almost 100 light-years. The sharp, composite, color image utilizing data from space and ground based telescopes, follows faint details of the region's gas and dust clouds against a backdrop of central Milky Way stars. Stellar winds and energetic light from hot, massive stars formed from M17's stock of cosmic gas and dust have slowly carved away at the remaining interstellar material producing the cavernous appearance and undulating shapes. M17 is also known as the Omega Nebula or the Swan Nebula. April 18, 2013  What kind of cloud is next to that mountain? A lenticular. This type of cloud forms in air that passes over a mountain, rises up again, and cools past the dew point -- so what molecular water carried in the air condenses into droplets. The layered nature of some lenticular clouds may make them appear, to some, as large alien spaceships. In this case, the mountain pictured is Mt. Hood located in Oregon, USA. Lenticular clouds can only form when conditions are right - for example this is first time this astrophotographer has seen a lenticular cloud at night near Mt. Hood. The above image was taken in mid-March about two hours before dawn. April 17, 2013  An expanded view from yesterday's picture, Large galaxies and faint nebulae highlight this deep image of the M81 Group of galaxies. First and foremost in the wide-angle 12-hour exposure is the grand design spiral galaxy M81, the largest galaxy visible in the image. M81 is gravitationally interacting with M82 just below it, a big galaxy with an unusual halo of filamentary red-glowing gas. Around the image many other galaxies from the M81 Group of galaxies can be seen. Together with other galaxy congregates including our Local Group of galaxies and the Virgo Cluster of galaxies, the M81 Group is part of the expansive Virgo Supercluster of Galaxies. This whole galaxy menagerie is seen through the faint glow of an Integrated Flux Nebula, a little studied complex of diffuse gas and dust clouds in our Milky Way Galaxy. April 16, 2013  One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy lies 11.8 million light-years away toward the northern constellation of the Great Bear (Ursa Major). The deep image of the region reveals details in the bright yellow core, but at the same time follows fainter features along the galaxy's gorgeous blue spiral arms and sweeping dust lanes. It also follows the expansive, arcing feature, known as Arp's loop, that seems to rise from the galaxy's disk at the upper right. Studied in the 1960s, Arp's loop has been thought to be a tidal tail, material pulled out of M81 by gravitational interaction with its large neighboring galaxy M82. But a subsequent investigation demonstrates that at least some of Arp's loop likely lies within our own galaxy. The loop's colors in visible and infrared light match the colors of pervasive clouds of dust, relatively unexplored galactic cirrus only a few hundred light-years above the plane of the Milky Way. Along with the Milky Way's stars, the dust clouds lie in the foreground of this remarkable view. M81's dwarf companion galaxy, Holmberg IX, can be seen just above the large spiral. On the sky, this image spans about 0.5 degrees, about the size of the Full Moon. April 15, 2013  Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula can be found in the direction of the constellation Cassiopeia, who Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. The Soul Nebula houses several open clusters of stars, a large radio source known as W5, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500 light years away, the Soul Nebula spans about 100 light years and is usually imaged next to its celestial neighbor the Heart Nebula (IC 1805). The above image appears mostly red due to the emission of a specific color of light emitted by excited hydrogen gas. April 14, 2013  Gliding silently through the outer Solar System, the Voyager 2 spacecraft camera captured Neptune and Triton together in crescent phase in 1989. The elegant picture of the gas giant planet and its cloudy moon was taken from behind just after closest approach. It could not have been taken from Earth because Neptune never shows a crescent phase to sunward Earth. The unusual vantage point also robs Neptune of its familiar blue hue, as sunlight seen from here is scattered forward, and so is reddened like the setting Sun. Neptune is smaller but more massive than Uranus, has several dark rings, and emits more light than it receives from the Sun. April 13, 2013  This week the Sun gave up its strongest solar flare so far in 2013, accompanied by a coronal mass ejection (CME) headed toward planet Earth. A false-color composite image in extreme ultraviolet light from the Solar Dynamics Observatory captures the moment, recorded on April 11 at 0711 UTC. The flash, a moderate, M6.5 class flare erupting from active region AR 11719, is near the center of the solar disk. Other active regions, areas of intense magnetic fields seen as sunspot groups in visible light, mottle the surface as the solar maximum approaches. Loops and arcs of glowing plasma trace the active regions' magnetic field lines. A massive cloud of energetic, charged particles, the CME will impact the Earth's magnetosphere by this weekend and skywatchers should be on the alert for auroral displays. April 12, 2013  On another April 12th, in 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human to see planet Earth from space. Commenting on his view from orbit he reported, "The sky is very dark; the Earth is bluish. Everything is seen very clearly". On yet another April 12th, in 1981 NASA launched the first space shuttle. To celebrate in 2013, consider this image from the orbiting International Space Station, a stunning view of the planet at night from low Earth orbit. Constellations of lights connecting the densely populated cities along the Atlantic east coast of the United States are framed by two Russian spacecraft docked at the space station. Easy to recognize cities include New York City and Long Island at the right. From there, track toward the left for Philadelphia, Baltimore, and then Washington DC near picture center. April 11, 2013  In a haunting vista you can never see, bright stars and the central Milky Way rise over the dark skyline of metropolitan Pudong in Shanghai, China. Looking east across the Huangpu River, the cityscape includes Pudong's 470 meter tall Oriental Pearl Tower. The night sky stretches from Antares and the stars of Scorpius at the far right, to Altair in Aquila at the left. To create the vision of an unseen reality, part of a series of Darkened Cities, photographer Thierry Cohen has combined a daytime image of the city skyline with an image matched in orientation from a dark sky region at the same latitude, just west of Merzouga, Morocco. The result finds the night sky that hours earlier also arced over Shanghai, but drowned in the lights of a city upon the sea. April 10, 2013   If you glanced out a side window of the International Space Station, what might you see? If you were Expedition 34 flight engineer Chris Hadfield, and you were looking out one of windows of Japan's Kibo Research Module on February 26, you might have seen the above vista. In the distance lies the darkness of outer space and the blueness of planet Earth. Large ISS objects include long solar panels that stretch diagonally from the upper left and the cylindrical airlock of the Pressurized Module that occupies the lower right. Numerous ports and platforms of the space station are visible and labeled on an annotated companion image. Of particular note is what looks to be a washer - dryer pair toward the image left, which are really NASA's HREP (near) and JAXA's MCE (far) research platforms. The gold foil covered experiment in the rear of HREP is the Remote Atmospheric and Ionospheric Detection System (RAIDS) that monitors atmospheric airglow, while MCE includes the Global Lightning and Sprite Measurements (JEM-GLIMS) instrument that monitors atmospheric electrical discharges. The current Expedition 35 crew is now commanded by Colonel Hadfield and scheduled to stay aboard the space station until May. April 9, 2013  It's the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula. Nicknamed the Eight-Burst Nebula and the Southern Ring Nebula, the glowing gas originated in the outer layers of a star like our Sun. In this reprocessed color picture, the hot purplish pool of light seen surrounding this binary system is energized by the hot surface of the faint star. Although photographed to explore unusual symmetries, it's the asymmetries that help make this planetary nebula so intriguing. Neither the unusual shape of the surrounding cooler shell nor the structure and placements of the cool filamentary dust lanes running across NGC 3132 are well understood. April 8, 2013  How far away is "redshift six"? Although humans are inherently familiar with distance and time, what is actually measured for astronomical objects is redshift, a color displacement that depends on exactly how energy density has evolved in our universe. Now since cosmological measurements in recent years have led to a concordance on what energy forms pervade our universe, it is now possible to make a simple table relating observed cosmological redshift, labeled "z", with standard concepts of distance and time, including the extrapolated time since the universe began. One such table is listed above, where redshift z is listed in the first and last columns, while the corresponding universe age in billions of years is listed in the central column. To find the meaning of the rest of the columns, please read the accompanying technical paper here. Although stars in our galaxy are effectively at cosmological redshift zero, the most distant supernovae seen occur out past redshift one, which the above chart shows occurred when the universe was approximately half its present age. By contrast, the most distant gamma-ray bursts yet observed occur out past redshift six, occurring when the universe was younger than one billion years old, less than 10 percent of its present age. April 7, 2013  Just days after sharing the western evening sky with Venus in 2007, the Moon moved on to Saturn - actually passing in front of the ringed planet Saturn when viewed in skies over Europe, northern Africa, and western Asia. Because the Moon and bright planets wander through the sky near the ecliptic plane, such occultation events are not uncommon, but they are dramatic, especially in telescopic views. For example, in this sharp image Saturn is captured emerging from behind the Moon, giving the illusion that it lies just beyond the Moon's bright edge. Of course, the Moon is a mere 400 thousand kilometers away, compared to Saturn's distance of 1.4 billion kilometers. Taken with a digital camera and 20 inch diameter telescope at the Weikersheim Observatory in southern Germany, the picture is a single exposure adjusted to reduce the difference in brightness between Saturn and the cratered lunar surface. April 6, 2013  No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right, the cloud tops reflect gently reddened sunlight filtered through the dusty troposphere, the lowest layer of the planet's nurturing atmosphere. A clear high altitude layer, visible along the dayside's upper edge, scatters blue sunlight and fades into the blackness of space. This picture actually is a single digital photograph taken in June of 2001 from the International Space Station orbiting at an altitude of 211 nautical miles. April 5, 2013  It looks like a double comet, but Comet PanSTARRS (C/2011 L4) is just offering skygazers a Messier moment. Outward bound and fading in this starry scene, the well-photographed comet is remarkably similar in brightness to M31, the Andromeda Galaxy. Tracking through northern skies just below the galaxy, the comet was captured as local midnight approached on April 3. Both comet and galaxy were visible to the eye and are immersed in the faint glow of northern lights as our own Milky Way galaxy arcs over a snowy field near Tänndalen, Sweden. Double star cluster h and chi Persei can be spotted along the Milky Way's arc high above the comet/galaxy pair. Follow the arc to bright Deneb, alpha star of the constellation Cygnus, at the right edge of the frame. April 4, 2013  This beautiful, bright, spiral galaxy is Messier 64, often called the Black Eye Galaxy or the Sleeping Beauty Galaxy for its heavy-lidded appearance in telescopic views. M64 is about 17 million light-years distant in the otherwise well-groomed northern constellation Coma Berenices. In fact, the Red Eye Galaxy might also be an appropriate moniker in this colorful composition of narrow and wideband images. The enormous dust clouds obscuring the near-side of M64's central region are laced with the telltale reddish glow of hydrogen associated with star forming regions. But they are not this galaxy's only peculiar feature. Observations show that M64 is actually composed of two concentric, counter-rotating systems of stars, one in the inner 3,000 light-years and another extending to about 40,000 light-years and rotating in the opposite direction. The dusty eye and bizarre rotation is likely the result of a billion year old merger of two different galaxies. April 3, 2013  Currently, comet PANSTARRS is passing nearly in front of the galaxy Andromeda. Coincidentally, both comet and galaxy appear now to be just about the same angular size. In physical size, even though Comet PANSTARRS is currently the largest object in the Solar System with a tail spanning about 15 times the diameter of the Sun, it is still about 70 billion times smaller than the Andromeda galaxy (M31). The above image was taken a few days ago near Syktyvkar, Russia. As C/2011 L4 (PANSTARRS) on the lower left recedes from the Sun and dims, it is returning to the northerly direction whence it came. When the comet will return is currently unknown. April 2, 2013  Do you see the horse's head? What you are seeing is not the famous Horsehead nebula toward Orion but rather a fainter nebula that only takes on a familiar form with deeper imaging. The main part of the above imaged molecular cloud complex is a reflection nebula cataloged as IC 4592. Reflection nebulas are actually made up of very fine dust that normally appears dark but can look quite blue when reflecting the light of energetic nearby stars. In this case, the source of much of the reflected light is a star at the eye of the horse. That star is part of Nu Scorpii, one of the brighter star systems toward the constellation of the Scorpion Scorpius. A second reflection nebula dubbed IC 4601 is visible surrounding two stars on the upper right of the image center. April 1, 2013 While visiting Wasaga Beach for Easter, I couldn't help but notice the remarkably clear weather that lasted the vast bulk of the weekend. On my first night up I decided to camp at the beach from sunset to about 9:30pm. I captured some panoramic sunset shots, as well as close ups of certain constellations such as Orion and Taurus - featuring the Orion Nebula and the Hyades and Pleiades plus Jupiter, moons et al. But what really caught my attention was when I was just about to pack up - a grey cloud spontaneously appeared to the north west, despite the forecasts saying that there shouldn't be any clouds in the sky. So I readied my camera and confirmed my suspicion - the Northern Lights had made their way all the way down to Wasaga Beach, just 150km from Toronto. As a bonus, Comet PANSTARRS is also visible as a badminton-birdie shaped object just above the horizon halfway to centre from the left, as well as the Andromeda Galaxy, M31. The constellation Cassiopeia centres the top of the image. March 31, 2013  Some 60 million light-years away in the southerly constellation Corvus, two large galaxies collided. But the stars in the two galaxies cataloged as NGC 4038 and NGC 4039 don't collide in the course of the ponderous, billion year or so long event. Instead, their large clouds of molecular gas and dust do, triggering furious episodes of star formation near the center of the cosmic wreckage. Spanning about 500 thousand light-years, this stunning view also reveals new star clusters and matter flung far from the scene of the accident by gravitational tidal forces. Of course, the visual appearance of the far-flung arcing structures gives the galaxy pair its popular name - The Antennae. March 30, 2013  The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years across, which surrounds the brighter, familiar planetary nebula. Made with data from the Nordic Optical Telescope in the Canary Islands, the composite picture shows extended emission from the nebula. Planetary nebulae have long been appreciated as a final phase in the life of a sun-like star. Only much more recently however, have some planetaries been found to have halos like this one, likely formed of material shrugged off during earlier active episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50,000 to 90,000 years. March 29, 2013  Orbiting in the plane of Saturn's rings, Saturnian moons have a perpetual ringside view of the gas giant planet. Of course, while passing near the ring plane the Cassini spacecraft also shares their stunning perspective. The thin rings themselves slice across the middle of this Cassini snapshot from April 2011. The scene looks toward the dark night side of Saturn, in the frame at the left, and the still sunlit side of the rings from just above the ringplane. Centered, over 1,500 kilometers across, Rhea is Saturn's second largest moon and is closest to the spacecraft, around 2.2 million kilometers away. To Rhea's right, shiny, 500 kilometer diameter Enceladus is about 3 million kilometers distant. Dione, 1,100 miles wide, is 3.1 million miles from Cassini's camera on the left, partly blocked by Saturn's night side. March 28, 2013  Bright spiral galaxy NGC 3169 appears to be unraveling in this cosmic scene, played out some 70 million light-years away just below bright star Regulus toward the faint constellation Sextans. Its beautiful spiral arms are distorted into sweeping tidal tails as NGC 3169 (left) and neighboring NGC 3166 interact gravitationally, a common fate even for bright galaxies in the local universe. In fact, drawn out stellar arcs and plumes, indications of gravitational interactions, seem rampant in the deep and colorful galaxy group photo. The picture spans 20 arc minutes, or about 400,000 light-years at the group's estimated distance, and includes smaller, dimmer NGC 3165 at the right. NGC 3169 is also known to shine across the spectrum from radio to X-rays, harboring an active galactic nucleus that is likely the site of a supermassive black hole. March 27, 2013  Why is this horizon so colorful? Because, opposite the Sun, it is raining. What is pictured above is actually just a common rainbow. It's uncommon appearance is caused by the Sun being unusually high in the sky during the rainbow's creation. Since every rainbow's center must be exactly opposite the Sun, a high Sun reflecting off of a distant rain will produce a low rainbow where only the very top is visible - because the rest of the rainbow is below the horizon. Furthermore, no two observers can see exactly the same rainbow - every person finds themselves exactly between the Sun and rainbow's center, and every observer sees the colorful circular band precisely 42 degrees from rainbow's center. The above image featuring the Eiffel Tower was taken in Paris, France last week. Although the intermittent thunderstorms lasted for much of the day, the horizon rainbow lasted for only a few minutes. March 26, 2013   If not distracted by the picturesque landscape, waterfalls, stars, and auroras, you might be able to find Comet PANSTARRS. The above image, capturing multiple terrestrial and celestial wonders in a single shot, was taken last week in southwest Iceland. The popular Gullfoss waterfalls are pictured under brilliant auroras that followed a M1-class solar flare and powerful Coronal Mass Ejection two days earlier. Give up on locating the comet? Comet PANSTARRS is faintly visible as a light blip just above the horizon toward the left of the above image. The comet remains more directly visible to northern observers with binoculars looking toward the western sky just after sunset. The photographer's website is found here should you wish to see similar photos. March 25, 2013  What is our universe made of? To help find out, ESA launched the Planck satellite to map, in unprecedented detail, slight temperature differences on the oldest surface known - the background sky left billions of years ago when our universe first became transparent to light. Visible in all directions, this cosmic microwave background is a complex tapestry that could only show the hot and cold patterns observed were the universe to be composed of specific types of energy that evolved in specific ways. The results, reported last week, confirm again that most of our universe is mostly composed of mysterious and unfamiliar dark energy, and that even most of the remaining matter energy is strangely dark. Additionally, Planck data impressively peg the age of the universe at about 13.81 billion years, slightly older than that estimated by various other means including NASA's WMAP satellite, and the expansion rate at 67.3 (+/- 1.2) km/sec/Mpc, slightly lower than previous estimates. Some features of the above sky map remain unknown, such as why the temperature fluctuations seem to be slightly greater on one half of the sky than the other. March 24, 2013  Inside the head of this interstellar monster is a star that is slowly destroying it. The monster, actually an inanimate pillar of gas and dust, measures over a light year in length. The star, not itself visible through the opaque dust, is bursting out partly by ejecting energetic beams of particles. Similar epic battles are being waged all over the star-forming Carina Nebula (NGC 3372). The stars will win in the end, destroying their pillars of creation over the next 100,000 years, and resulting in a new open cluster of stars. The pink dots are newly formed stars that have already been freed from their birth monster. The above image is only a small part of a highly detailed panoramic mosaic of the Carina Nebula taken by the Hubble Space Telescope in 2007. The technical name for the stellar jets are Herbig-Haro objects. How a star creates Herbig-Haro jets is an ongoing topic of research, but it likely involves an accretion disk swirling around a central star. A second impressive Herbig-Haro jet is visible across the bottom. March 23, 2013  Cosmic dust clouds ripple across this infrared portrait of our Milky Way's satellite galaxy, the Large Magellanic Cloud. In fact, the remarkable composite image from the Herschel Space Observatory and the Spitzer Space Telescope show that dust clouds fill this neighboring dwarf galaxy, much like dust along the plane of the Milky Way itself. The dust temperatures tend to trace star forming activity. Spitzer data in blue hues indicate warm dust heated by young stars. Herschel's instruments contributed the image data shown in red and green, revealing dust emission from cooler and intermediate regions where star formation is just beginning or has stopped. Dominated by dust emission, the Large Magellanic Cloud's infrared appearance is different from views in optical images. But this galaxy's well-known Tarantula Nebula still stands out, easily seen here as the brightest region to the left of center. A mere 160,000 light-years distant, the Large Cloud of Magellan is about 30,000 light-years across. March 22, 2013  The broad dust tail of Comet PanSTARRS (C/2011 L4) has become a familiar sight for many northern hemisphere comet watchers, as the comet fades but rises higher above the western horizon after sunset. This view of the popular comet may seem a little fantastic, though. Sweeping away from the Sun and trailing behind the comet's orbit, the curving dust tail also seems to stream away from a shining mountaintop castle. Comet Castle might be an appropriate name in this scene, but its traditional name is Castle Hohenzollern. Taken on March 15 with an extreme telephoto lens, the Comet Castle image was captured in exceptionally clear skies about 80 kilometers away from Stuttgart, Germany. March 21, 2013  Moving left to right near the center of this beautifully detailed color composite, the thin, bright, braided filaments are actually long ripples in a sheet of glowing gas seen almost edge on. The interstellar shock wave plows through space at over 500,000 kilometers per hour. Cataloged as NGC 2736, its elongated appearance suggests its popular name, the Pencil Nebula. The Pencil Nebula is about 5 light-years long and 800 light-years away, but represents only a small part of the Vela supernova remnant. The Vela remnant itself is around 100 light-years in diameter, the expanding debris cloud of a star that was seen to explode about 11,000 years ago. Initially, the shock wave was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. In the narrowband, wide field image, red and blue-green colors track the characteristic glow of ionized hydrogen and oxygen atoms. March 20, 2013  The Great Nebula in Orion, an immense, nearby starbirth region, is probably the most famous of all astronomical nebulas. Here, glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away. In the above deep image in assigned colors highlighted by emission in oxygen and hydrogen, wisps and sheets of dust and gas are particularly evident. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion. In addition to housing a bright open cluster of stars known as the Trapezium, the Orion Nebula contains many stellar nurseries. These nurseries contain much hydrogen gas, hot young stars, proplyds, and stellar jets spewing material at high speeds. Also known as M42, the Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun. March 19, 2013  How did the Moon form? To help find out, NASA launched the twin Gravity Recovery and Interior Laboratory (GRAIL) satellites in 2011 to orbit and map the Moon's surface gravity in unprecedented detail. Pictured above is a resulting GRAIL gravity map, with regions of slightly lighter gravity shown in blue and regions of slightly stronger gravity shown in red. Analysis of GRAIL data indicates that the moon has an unexpectedly shallow crust than runs about 40 kilometers deep, and an overall composition similar to the Earth. Although other surprising structures have been discovered that will continue to be investigated, the results generally bolster the hypothesis that the Moon formed mostly from Earth material following a tremendous collision in the early years of our Solar System, about 4.5 billion years ago. After completing their mission and running low on fuel, the two GRAIL satellites, Ebb and Flow, were crashed into a lunar crater at about 6,000 kilometer per hour. March 18, 2013  Have you seen the comet? As Comet PANSTARRS fades, careful observers - even with unaided eyes - should still be able to find the shedding ice ball on the western horizon just after sunset. Pictured above, Comet PANSTARRS (C/2011 L4) was pointed out from a hilltop last week on First Encounter Beach in Massachusetts, USA. The comet was discovered by - and is named for - the Pan-STARRS astronomical sky survey that discovered it. As the comet now recedes from both the Earth and the Sun, it will remain visible further into the night, although binoculars or a small telescope will soon to be needed to find it. March 17, 2013  What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon's outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this had never been seen before - supernovas and novas expel matter out into space. Although the V838 Mon flash appears to expel material into space, what is seen in the above image from the Hubble Space Telescope is actually an outwardly moving light echo of the bright flash. In a light echo, light from the flash is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. V838 Mon lies about 20,000 light years away toward the constellation of the unicorn (Monoceros), while the light echo above spans about six light years in diameter. March 16, 2013  Still looking for that comet? Comet PanSTARRS (C/2011 L4) naked-eye appearance in the northern hemisphere is described by successful comet spotters as a dim star with faint a tail. If you want to catch it the next few days could be your best bet. Start looking low and almost due west about 45 minutes after sunset. Of course, clear skies and a pair of binoculars should help a lot. Sky photographer Jean-Luc Dauvergne found suitable weather and western horizon for this comet and crescent Moon portrait after a road trip on March 13. Seeing PanSTARRS for the first time, he recorded the beautiful twilight scene with a telephoto lens near historical Alesia in France. March 15, 2013  After appearing in a popular photo opportunity with a young crescent Moon near sunset, naked-eye Comet PanSTARRS continues to rise in northern hemisphere skies. But this remarkable interplanetary perspective from March 13, finds the comet posing with our fair planet itself - as seen from the STEREO Behind spacecraft. Following in Earth's orbit, the spacecraft is nearly opposite the Sun and looks back toward the comet and Earth, with the Sun just off the left side of the frame. At the left an enormous coronal mass ejection (CME) is erupting from a solar active region. Of course, CME, comet, and planet Earth are all at different distances from the spacecraft. (The comet is closest.) The processed digital image is the difference between two consecutive frames from the spacecraft's SECCHI Heliospheric Imager, causing the strong shadowing effect for objects that move between frames. Objects that are too bright create the sharp vertical lines. The processing reveals complicated feather-like structures in Comet PanSTARRS's extensive dust tail. March 14, 2013  In silhouette against the colorful evening twilight glow, clouds part in this much anticipated magic moment. The scene captures naked-eye Comet PanSTARRS peeking into northern hemisphere skies on March 12. The comet stands over the western horizon after sunset, joined by the thin, flattened crescent of a day old Moon. Posing for its own beauty shot, the subtly lit dome of the 4.2 meter William Herschel Telescope is perched above cloud banks on the Canary Island of La Palma. While PanSTARRS has not quite developed into the spectacular comet once hoped for, it is still growing easier to see in the north. In coming days it will steadily climb north, farther from the Sun into darker western evening skies. March 13, 2013  Planetary nebulae can look simple, round, and planet-like in small telescopes. But images from the orbiting Hubble Space Telescope have become well known for showing these fluorescent gas shrouds of dying Sun-like stars to possess a staggering variety of detailed symmetries and shapes. This composite color Hubble image of NGC 6751, the Glowing Eye Nebula, is a beautiful example of a classic planetary nebula with complex features. It was selected in April of 2000 to commemorate the tenth anniversary of Hubble in orbit, but was reprocessed recently by an amateur as part of the Hubble Legacy program. Winds and radiation from the intensely hot central star (140,000 degrees Celsius) have apparently created the nebula's streamer-like features. The nebula's actual diameter is approximately 0.8 light-years or about 600 times the size of our Solar System. NGC 6751 is 6,500 light-years distant in the high-flying constellation of the Eagle (Aquila). March 12, 2013  How fast can a black hole spin? If any object made of regular matter spins too fast - it breaks apart. But a black hole might not be able to break apart - and its maximum spin rate is really unknown. Theorists usual model rapidly rotating black holes with the Kerr solution to Einstein's General Theory of Relativity, which predicts several amazing and unusual things. Perhaps its most easily testable prediction, though, is that matter entering a maximally rotating black hole should be last seen orbiting at near the speed of light, as seen from far away. This prediction was tested recently by NASA's NuSTAR and ESA's XMM satellites by observing the supermassive black hole at the center of spiral galaxy NGC 1365. The near light-speed limit was confirmed by measuring the heating and spectral line broadening of nuclear emissions at the inner edge of the surrounding accretion disk. Pictured above is an artist's illustration depicting an accretion disk of normal matter swirling around a black hole, with a jet emanating from the top. Since matter randomly falling into the black hole should not spin up a black hole this much, the NuSTAR and XMM measurements also validate the existence of the surrounding accretion disk. March 11, 2013  Why does a volcanic eruption sometimes create lightning? Pictured above, the Sakurajima volcano in southern Japan was caught erupting in early January. Magma bubbles so hot they glow shoot away as liquid rock bursts through the Earth's surface from below. The above image is particularly notable, however, for the lightning bolts caught near the volcano's summit. Why lightning occurs even in common thunderstorms remains a topic of research, and the cause of volcanic lightning is even less clear. Surely, lightning bolts help quench areas of opposite but separated electric charges. One hypothesis holds that catapulting magma bubbles or volcanic ash are themselves electrically charged, and by their motion create these separated areas. Other volcanic lightning episodes may be facilitated by charge-inducing collisions in volcanic dust. Lightning is usually occurring somewhere on Earth, typically over 40 times each second. March 10, 2013   Aloha and welcome to a breathtaking skyscape. The dreamlike panoramic view looks out from the 4,200 meter volcanic summit of Mauna Kea, Hawai'i, across a layer of clouds toward a starry night sky and the rising Milky Way. Anchoring the scene on the far left is the dome of the Canada-France-Hawaii Telescope (CFHT), with north star Polaris shining beyond the dome to the right. Farther right, headed by bright star Deneb, the Northern Cross asterism is embedded along the plane of the Milky Way as it peeks above the horizon. Both Northern Cross and brilliant white Vega hang over a foreground grouping of cinder cones. Near the center are the reddish nebulae, stars and dust clouds of the central Milky Way. Below, illumination from the city lights of Hilo creates an eerie, greenish glow in the clouds. Red supergiant star Antares shines above the Milky Way's central bulge while bright Alpha Centauri lies still farther right, along the dusty galactic plane. Finally, at the far right is the large Gemini North Observatory. The compact group of stars known as the Southern Cross is just left of the telescope dome. March 9, 2013  Sweeping quickly through southern skies on March 5, Comet PanSTARRS (C/2011 L4) follows the Sun toward the western horizon in this twilight scene. In the foreground is Australia's CSIRO Parkes Radio Telescope, a 64 meter wide steerable dish that is no stranger to the space age exploration of comets. In March of 1986 the Parkes dish tracked ESA's Giotto spacecraft as it flew by Comet Halley and received the first ever closeup images of Halley's nucleus. At naked-eye visibility, Comet PanSTARRS made its closest approach to planet Earth on March 5. Its closest approach to the Sun will be on March 10. Heading north, PanSTARRS now begins a much anticipated appearance low in the northern hemisphere's western skies after sunset. On March 12, look for the comet hugging the western horizon near a young crescent Moon. March 8, 2013   Want to use a cluster of galaxies as a telescope? It's easier than you might think as distant galaxy clusters naturally act as strong gravitional lenses. In accordance with Einstein's theory of general relativity, the cluster gravitational mass, dominated by dark matter, bends light and creates magnified, distorted images of even more distant background galaxies. This sharp infrared Hubble image illustrates the case for galaxy cluster Abell 68 as a gravitational telescope, explored by amateur astronomer Nick Rose during the ESA-Hubble Hidden Treasures image processing competition. Labels 1 and 2 show two lensed images of the same background galaxy. The distorted galaxy image labeled 2 resembles a vintage space invader! Label 3 marks a cluster member galaxy, not gravitationally lensed, stripped of its own gas as it plows through the denser intergalactic medium. Label 4 includes many background galaxies imaged as elongated streaks and arcs. Abell 68 itself is some 2.1 billion light-years distant toward the constellation Vulpecula. The central region of the cluster covered in the Hubble view spans over 1.2 million light-years. March 7, 2013  Fomalhaut (sounds like "foam-a-lot") is a bright, young, star, a short 25 light-years from planet Earth in the direction of the constellation Piscis Austrinus. In this sharp composite from the Hubble Space Telescope, Fomalhaut's surrounding ring of dusty debris is imaged in detail, with overwhelming glare from the star masked by an occulting disk in the camera's coronagraph. Astronomers now identify, the tiny point of light in the small box at the right as a planet about 3 times the mass of Jupiter orbiting 10.7 billion miles from the star (almost 23 times the Sun-Jupiter distance). Designated Fomalhaut b, the massive planet probably shapes and maintains the ring's relatively sharp inner edge, while the ring itself is likely a larger, younger analog of our own Kuiper Belt - the solar system's outer reservoir of icy bodies. The Hubble data represent the first visible-light image of a planet circling another star. March 6, 2013  Bright clusters and nebulae abound in the ancient northern constellation of Auriga. The region includes the open star cluster M38, emission nebula IC 410 with Tadpoles, Auriga's own Flaming Star Nebula IC 405, and this interesting pair IC 417 (lower left) and NGC 1931. An imaginative eye toward the expansive IC 417 and diminutive NGC 1931 suggests a cosmic spider and fly. About 10,000 light-years distant, both represent young, open star clusters formed in interstellar clouds and still embedded in glowing hydrogen gas. For scale, the more compact NGC 1931 is about 10 light-years across. March 5, 2013   Two impressive comets will both reach their peak brightness during the next two weeks. Taking advantage of a rare imaging opportunity, both of these comets were captured in the sky together last week over the Atacama desert in South America. Comet C/2012 F6 (Lemmon), visible on the upper left of the above image, is sporting a long tail dominated by glowing green ions. Comet C/2011 L4 (PanSTARRS), visible near the horizon on the lower right, is showing a bright tail dominated by dust reflecting sunlight. The tails of both comets point approximately toward the recently set Sun. Comet Lemmon will be just barely visible to the unaided eye before sunset in southern skies for the next week, and then best viewed with binoculars as it fades and moves slowly north. Comet PanSTARRS, however, will remain visible in southern skies for only a few more days, after which it will remain bright enough to be locatable with the unaided eye as it moves into northern skies. To find the giant melting snowball PanSTARRS, sky enthusiasts should look toward the western horizon just after sunset. Deep sky observers are also monitoring the brightening of Comet C/2012 S1 (ISON), which may become one of the brightest objects in the entire night sky toward the end of 2013. March 4, 2013  Sprawling across almost 200 light-years, emission nebula IC 1805 is a mix of glowing interstellar gas and dark dust clouds. Derived from its Valentine's-Day-approved shape, its nickname is the Heart Nebula. About 7,500 light-years away in the Perseus spiral arm of our galaxy, stars were born in IC 1805. In fact, near the cosmic heart's center are the massive hot stars of a newborn star cluster also known as Melotte 15, about 1.5 million years young. A little ironically, the Heart Nebula is located in the constellation of the mythical Queen of Aethiopia (Cassiopeia). This deep view of the region around the Heart Nebula spans about two degrees on the sky or about four times the diameter of the Full Moon. March 3, 2013  One of the natural wonders of planet Earth, the Grand Canyon in the American southwest stretches across this early evening skyscape. The digitally stacked sequence reveals the canyon's layers of sedimentary rock in bright moonlight. Exposed sedimentary rock layers range in age from about 200 million to 2 billion years old, a window to history on a geological timescale. A recent study has found evidence that the canyon itself may have been carved by erosion as much as 70 million years ago. With the camera fixed to a tripod while Earth rotates, each star above carves a graceful arc through the night sky. The concentric arcs are centered on the north celestial pole, the extension of Earth's rotation axis into space, presently near the bright star Polaris. March 2, 2013  Each day on planet Earth can have a serene beginning at sunrise as the sky gently grows bright over a golden eastern horizon. This sunrise panorama seems to show such a moment on the winter morning of February 15. In the mist, a calm, mirror-like stretch of the Miass River flows through the foreground along a frosty landscape near Chelyabinsk, Russia. But the long cloud wafting through the blue sky above is the evolving persistent train of the Chelyabinsk Meteor. The vapor trail was left by the space rock that exploded over the city only 18 minutes earlier, causing extensive damage and injuring over 1,000 people. A well-documented event, the numerous webcam and dashcam video captures from the region soon contributed to a reconstruction of the meteor's trajectory and an initial orbit determination. Preliminary findings indicate the parent meteoriod belonged to the Apollo class of Earth crossing asteroids. March 1, 2013  The colors of the solar system's innermost planet are enhanced in this tantalizing view, based on global image data from the Mercury-orbiting MESSENGER spacecraft. Human eyes would not discern the clear color differences but they are real none the less, indicating distinct chemical, mineralogical, and physical regions across the cratered surface. Notable at the upper right, Mercury's large, circular, tan colored feature known as the Caloris basin was created by an impacting comet or asteroid during the solar system's early years. The ancient basin was subsequently flooded with lava from volcanic activity, analogous to the formation of the lunar maria. Color contrasts also make the light blue and white young crater rays, material blasted out by recent impacts, easy to follow as they extend across a darker blue, low reflectance terrain. |
Re: Terry's Astronomy Thread.
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Also, when i said "Do you think it'll be good for taking long exposures as well?" in my previous post, i was referring to the stability of the mount as i've read that a decent mount is required for astrophotography. I'm new to both astronomy and photography so bear with me if i sound clueless lol. |
Re: Terry's Astronomy Thread.
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http://www.telescope.com/Mounts-Trip...e=SortByRating http://www.telescope.com/Mounts-Trip...ByRating#tab-6 Here are a couple tripods that would help you shoot long exposure pictures. One of them is considerably more expensive than the other, but remember these are dollar values, so for your currency they might be a bit cheaper. Both of them appear to have very positive reviews, which is typically a good sign of a good product. Also for the more inexpensive one, take a look at some of the photos that people have taken with it as a mount! What's in the sky tonight? April 7, 2012 -The bright Moon rises around the end of twilight below Saturn and Spica in the east-southeast. Later in the evening the three shine higher: a long, narrow triangle with the Moon at the bottom. -Saturn (magnitude +0.2, in Virgo) is at opposition April 15th. This week it rises almost around sunset and stands highest in the south around 1 or 2 a.m. daylight-saving time. Shining 5½° to Saturn's right is Spica: fainter, bluer, and twinklier. -Keep careful watch on Saturn and its rings in a telescope. In the days leading up to opposition, watch for the Seeliger effect: a brightening of the rings with respect to the globe. This happens because the solid particles making up the rings backscatter sunlight (reflect it back in the direction it came from) more effectively than the planet's cloudtops do. Astro Picture of the Day: April 7, 2012 Source: The star near the top is so bright that it is sometimes hard to notice the galaxy toward the bottom. Pictured above, both the star, Regulus, and the galaxy, Leo I, can be found within one degree of each other toward the constellation of the Lion (Leo). Regulus is part of a multiple star system, with a close companion double star visible to the lower left of the young main sequence star. Leo I is a dwarf spheroidal galaxy in the Local Group of galaxies dominated by our Milky Way Galaxy and M31. Leo I is thought to be the most distant of the several known small satellite galaxies orbiting our Milky Way Galaxy. Regulus is located about 75 light years away, in contrast to Leo 1 which is located about 800,000 light years away. Regulus is easy to spot these days as it is accompanied by Mars after sunset and hangs around until the early morning hours. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 8, 2012 -As twilight fades down, Look for bright Sirius in the southwest, Orion's horizontal Belt off to the right, and Aldebaran and Venus farther to the right in the west. They all form a long, almost straight line. The line is horizontal if you live near latitude 38° north. -Venus (magnitude –4.6; in Taurus) shines very high and ever more brilliant in the west during and after twilight. It doesn't set now until some 2½ hours after dark. This is just about as high and bright as Venus ever becomes in its 8-year cycle of apparitions. Look to its lower right for the Pleiades, and to its left for orange Aldebaran. Astro Picture of the Day: April 8, 2012 Source: Hurtling through a cosmic dust cloud some 400 light-years away, the lovely Pleiades or Seven Sisters star cluster is well-known for its striking blue reflection nebulae. In the dusty sky toward the constellation Taurus and the Orion Arm of our Milky Way Galaxy, this remarkable image shows the famous star cluster at the upper left. But lesser known dusty nebulae lie along the region's fertile molecular cloud, within the 10 degree wide field, including the bird-like visage of LBN 777 near center. Small bluish reflection nebula VdB 27 at the lower right is associated with the young, variable star RY Tau. At the distance of the Pleiades, the 5 panel mosaic spans nearly 70 light-years. The dust clouds are seen as brown clouds, not to be confused with clouds that might be seen in terrestrial levels. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 9, 2012 -The Big Dipper, high in the northeast, dumps water into the dim Little Dipper during evening at this time of year. -Jupiter is sinking ever lower toward the sunset far below Venus. Jupiter is rounding toward the far side of the Sun, which is why a telescope shows it a disappointingly small 33 arcseconds wide. In addition, Jupiter appears increasingly fuzzy at its ever-lower altitude. Astro Picture of the Day: April 9, 2012 Source: Strange shapes and textures can be found in neighborhood of the Cone Nebula. The unusual shapes originate from fine interstellar dust reacting in complex ways with the energetic light and hot gas being expelled by the young stars. The brightest star on the right of the above picture is S Mon, while the region just below it has been nicknamed the Fox Fur Nebula for its color and structure. The blue glow directly surrounding S Mon results from reflection, where neighboring dust reflects light from the bright star. The red glow that encompasses the whole region results not only from dust reflection but also emission from hydrogen gas ionized by starlight. S Mon is part of a young open cluster of stars named NGC 2264, located about 2500 light years away toward the constellation of the Unicorn (Monoceros). The origin of the mysterious geometric Cone Nebula, visible on the far left, remains a mystery. |
Re: Terry's Astronomy Thread.
This thread has now lasted one month! What has happened in that month?
-1,200 views. -67 posts. -31 Pictures and a month of learning what's in the sky that most of us can see. -Contributions from members about finding helpful links to astronomical related sites, cameras, telescopes. -A stickied thread. -1,200 views / 31 days means on average, 38.7 people view this thread a day. Thank you for helping this thread maintain its splendour. -Several new features, including a Light pollution map, Messier Map, new links. My question now comes to you, the viewer: What would you like to see added to this thread? Perhaps someone could make a neat banner to head the thread. I'm in the final exam period so I don't quite have the time to do it, but a major thank you to all who regularly view this thread! Now having said that... What's in the sky tonight? April 10, 2012 -The bright star high to the upper right of Venus these evenings is Capella, the Goat Star. It's the same yellow-white color, and thus the same temperature, as the Sun. The wavelength of the star is a good measurement of indicating how hot a star is. It's also how we know the temperature of our own sun! The shorter the wavelength, the warmer the star. Wavelengths are also used to calculate how fast the star is moving to, or from us by how much it has redshifted (how much the elemental spectra of a star has moved to the longer end of the spectrum compared to the elemental spectra at rest state found here, and as such, is moving away) or blueshifted (how much the elemental spectra of a star has moved to the shorter end of the spectrum compared to the elemental spectra at rest state found here, and as such, is heading towards us). The greater the shift, the faster the object is moving to or from us. -You can see Venus in the clear blue sky of daytime, if your eye lands right on it. The best time to examine Venus in a telescope is late afternoon or around sunset. It's now a thick crescent that has grown to 27 arcseconds tall as it rounds the Sun and approaches Earth. Astro Picture of the Day: April 10, 2012 Source: Does part of this image look familiar? In the second picture in as many days, the Cone Nebula is revisited with its many friends in a more zoomed out scale. Found in Monoceros, pictured above is a star forming region cataloged as NGC 2264, the complex jumble of cosmic gas and dust is about 2,700 light-years distant and mixes reddish emission nebulae excited by energetic light from newborn stars with dark interstellar dust clouds. Where the otherwise obscuring dust clouds lie close to the hot, young stars they also reflect starlight, forming blue reflection nebulae. The above image spans about 3/4 degree or nearly 1.5 full moons, covering 40 light-years at the distance of NGC 2264. Its cast of cosmic characters includes the Fox Fur Nebula, whose convoluted pelt lies at the upper left, bright variable star S Mon immersed in the blue-tinted haze just below the Fox Fur, and the Cone Nebula near the tree's top. Of course, the stars of NGC 2264 are also known as the Christmas Tree star cluster. The triangular tree shape traced by the stars appears sideways here, with its apex at the Cone Nebula and its broader base centered near S Mon. |
Re: Terry's Astronomy Thread.
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Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 11, 2012 -With the Moon gone from the evening sky, it's deep-sky observing time again. Telescope users are familiar with the "Leo Trio" of galaxies (M65, M66, and NGC 3628) by the little chair asterism in the back leg of Leo. Can you detect M65 and M66 with binoculars? -Toronto residents should consider the International Space Station Tracker as the Space Station makes very visible passes over the city tonight and an even brighter appearance tomorrow night at a reasonable hour. There will be two passes tonight: Pass A: This pass rises above the horizon at 20:20:54, and enters the shadow of the Earth at 20:30:09. The maximum altitude time is 20:25:52, and it will appear 26 degrees high at its peak. At it's peak it will appear in the Southeast. Event Time Altitude Azimuth Distance (km) Rises above horizon 20:20:54 -0° 209° (SSW) 2,283 Reaches 10° altitude 20:23:09 10° 196° (SSW) 1,435 Maximum altitude 20:25:52 26° 138° (SE ) 818 Enters shadow 20:30:09 3° 69° (ENE) 1,998 Drops below 10° altitude20:28:40 10° 78° (ENE) 1,446 Use the following star map to get a feel for the location and how fast the space station travels throughout it's ~6 minute appearance. More details can be found in the link in "Pass A". Pass B: This is the better of the two passes tonight. At its peak, the space station will be almost 300 km closer to us, and the sun will also have long set. The maximum altitude will be 45 degrees - halfway up the sky. Event Time Altitude Azimuth Distance (km) Rises above horizon 21:56:46 0° 253° (WSW) 2,292 Reaches 10° altitude 21:58:52 10° 260° (W ) 1,442 Maximum altitude 22:02:00 45° 335° (NNW) 553 Enters shadow 22:02:37 39° 10° (N ) 615 Use the following star map to get a feel for the location and how fast the space station travels throughout it's ~6 minute appearance. More details can be found in the link in "Pass B". NOTE: These times are specifically calculated for TORONTO, ON. If you're interested and wish to have a shot at looking at the Space Station, open the "International Space Station Tracker" tab in this thread, and follow the instructions. Good luck, and don't blink! Astro Picture of the Day: April 11, 2012 Source: Why would Venus appear oval? Venus has been seen countless times from the surface of the Earth, and every time the Earth's atmosphere has dispersed its light to some degree. When the air has just the right amount of dust or water droplets, small but distant objects like Venus appear spread out into an angularly large aureole. Aureoles are not unusual to see and are frequently noted as circular coronas around the Sun or Moon. Recently, however, aureoles have been imaged that are not circular but distinctly oval. The above oval Venusian aureole was imaged by the astrophotographer who first noted the unusual phenomenon three years ago. Initially disputed, the unusual distortion has now been confirmed multiple times by several different astrophotographers. What causes the ellipticity is currently unknown, and although several hypotheses hold that horizontally oriented ice crystals are responsible, significant discussions about it are still taking place. |
Re: Terry's Astronomy Thread.
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http://www.luminous-landscape.com/tu...60-night.shtml Especially read "rule of 600" because that will be handy when choosing the exposure time. I'm feeling adventurous, if skies are well tonight I might try some sky shots of my own. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 12, 2012 -Near the back leg of Leo is the asteroid 5 Astraea, about magnitude 9.6. Use this preview to track the location of the asteroid. It can be found on page 52. -Toronto residents get the best view of the space station tonight of the month incase you missed the 2 passes last night. The next good pass is well over a week away, so take advantage of the weather. You will be looking for a bright white-yellow ball moving at a high speed (think about the speed of a plane, but only identifyable as a dot) beginning by cutting through Orion, past Gemini, and passing the Big Dipper, before passing Bootes and siappearing into the Corona Borealis constellation. Don't miss out on this one! Pass A: This pass rises above the horizon at 21:00:38, and enters the shadow of the Earth at 21:09:33. The maximum altitude time is 21:05:54, and it will appear 80 degrees high at its peak in the northwest - just 10 degrees shorter than the maximum. Event Time Altitude Azimuth Distance (km) Rises above horizon 21:00:38 -0° 239° (WSW) 2,288 Reaches 10° altitude 21:02:41 10° 241° (WSW) 1,439 Maximum altitude 21:05:54 80° 320° (NW ) 407 Enters shadow 21:09:33 8° 57° (ENE) 1,606 Drops below 10° altitude 21:09:10 10° 56° (ENE) 1,449 Use the following star map to get a feel for the location and how fast the space station travels throughout it's ~6 minute appearance. More details can be found in the link in "Pass A". NOTE: These times are specifically calculated for TORONTO, ON. If you're interested and wish to have a shot at looking at the Space Station, open the "International Space Station Tracker" tab in this thread, and follow the instructions. Good luck, and don't blink! Astro Picture of the Day: April 12, 2012 Source: On another April 12th, in 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human to see planet Earth from space. Commenting on his view from orbit he reported, "The sky is very dark; the Earth is bluish. Everything is seen very clearly". To celebrate, consider this recent image from the orbiting International Space Station. A stunning view of the planet at night from an altitude of 240 miles, it was recorded on March 28. The lights of Moscow, Russia are near picture center and one of the station's solar panel arrays is on the left. Aurora and the glare of sunlight lie along the planet's gently curving horizon. Stars above the horizon include the compact Pleiades star cluster, immersed in the auroral glow. The effect of light pollution is shown in this photo as brown-yellow light domes are clearly visible. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 13, 2012 -Summer preview: stay up until 11 and look northeast, and you'll get a preview of bright Vega, the "Summer Star" in little Lyra, climbing into good view. This is an astronomical sign that summer is approaching for North Americans. -Last-quarter Moon (exact at 6:50 a.m. on this date EDT). Astro Picture of the Day: April 13, 2012 Source: Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light. The brightness of the nebula is determined by the size and density of the reflecting grains, and by the color and brightness of the neighboring star(s). NGC 1435, pictured above, surrounds Merope (23 Tau), one of the brightest stars in the Pleiades (M45). The Pleiades nebulosity is caused by a chance encounter between an open cluster of stars and a dusty molecular cloud. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 14, 2012 -Saturn is at opposition, opposite the Sun. It rises around sunset, shines highest in the middle of the night, and sets around sunrise. Telescope users: watch for the Seeliger effect, described under Saturn in "This Week's Planet Roundup" below. -Mars ends its retrograde (westward) motion for the year and resumes heading east against the background stars. Watch it pull away from Regulus in the coming weeks: slowly at first, then faster. Astro Picture of the Day: April 14, 2012 Source: How many moons does Saturn have? So far 62 have been discovered, the smallest only a fraction of a kilometer across. Six of its largest satellites can be seen here, though, in a sharp Saturnian family portrait taken on March 9. Larger than Earth's Moon and even slightly larger than Mercury, Titan has a diameter of 5,150 kilometers and starts the line-up at the lower left. Continuing to the right across the frame are Mimas, Tethys, [Saturn], Enceladus, Dione, and Rhea at far right. Saturn's first known natural satellite, Titan was discovered in 1655 by Dutch astronomer Christiaan Huygens, while most recently the satellite provisionally designated S/2009 S1 was found by the Cassini Imaging Science Team in 2009. Tonight, Saturn reaches opposition in planet Earth's sky, offering the best telescopic views of the ringed planet and moons. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 15, 2012 -Venus (magnitude –4.6; in Taurus) is shining the highest and brightest it ever appears in the evening sky during its 8-year cycle of repeating apparitions. Venus comes into easy view high in the west soon after sunset. It doesn't set in the northwest until around 11 or even midnight daylight saving time (depending on where you live). You can see Venus through the clear blue sky of day if your eye lands right on it; look for it 44° (4 or 5 fist-widths at arm's length) to the Sun's celestial east-northeast. Look high to Venus's upper right at dusk for Capella, to its lower left for Aldebaran, and to its lower right for the Pleiades. Far below Venus in twilight is Jupiter. The best time to examine Venus in a telescope is late afternoon or around sunset. It's now a thick crescent 30 arcseconds tall and 40% sunlit, waning and enlarging week by week as it swings toward Earth. -Keep careful watch on Saturn and its rings in a telescope. With Saturn at or near near opposition, notice the Seeliger effect: a temporary brightening of the rings with respect to the globe. This happens because the solid particles making up the rings backscatter sunlight (reflect it back in the direction it came from) more effectively than the planet's cloudtops do. Compare how the rings and globe look now with with how they look a week or more past opposition. Astro Picture of the Day: April 15, 2012 Source: This telescopic close-up shows off the otherwise faint emission nebula IC 410 in striking false-colors. It also features two remarkable inhabitants of the cosmic pond of gas and dust above and left of center, the tadpoles of IC 410. The picture is a composite of images taken through both broad and narrow band filters. The narrow band data traces atoms in the nebula, with emission from sulfur atoms in red, hydrogen atoms in green, and oxygen in blue. Partly obscured by foreground dust, the nebula itself surrounds NGC 1893, a young galactic cluster of stars that energizes the glowing gas. Composed of denser cooler gas and dust the tadpoles are around 10 light-years long, potentially sites of ongoing star formation. Sculpted by wind and radiation from the cluster stars, their tails trail away from the cluster's central region. IC 410 lies some 12,000 light-years away, toward the constellation Auriga. |
Re: Terry's Astronomy Thread.
Fantastic thread, even for casuals just looking at the pictures.
I absolutely love the picture from April 12. I don't see this video posted anywhere in this thread, so: http://www.youtube.com/watch?v=FG0fTKAqZ5g An incredible time-lapse from the ISS for those interested. |
Re: Terry's Astronomy Thread.
This thread is the most up-to-date thread I've ever seen. D:
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Re: Terry's Astronomy Thread.
Even though I don't understand a lot of it. The pictures are amazing and open my eyes to what we're all missing out on. There's just so much we don't know.
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Re: Terry's Astronomy Thread.
Thanks Reach, gold stinger, Winrar for the positive feedback! Reach, I have added the ISS video under the ISS tab because that's a great video and really gives perspective on what it's like to see the Earth from above.
If there's something you want to see added to the thread, post a suggestion! It might just start appearing in the main post. What's in the sky tonight? April 16, 2012 -As twilight fades, Look for bright Sirius in the southwest, Orion's horizontal Belt off to the right (with Betelgeuse above it, Rigel below it), and Aldebaran and Venus farther to the right in the west. As it sinks ever lower in the west, notice how it starts twinkling more violently, even temporarily changing colours to yellows and reds. Why is this? As it lowers into the horizon, Sirius and other stars have more atmosphere to travel to from your eyes to the location of the star. Because of this, the light of the star is often distorted through the increased atmosphere and can be strong enough to change what colour rays reach your eyes. This is the same reason why the Sun rises reddish in colour, and why the moon also rises in a red-orange colour. It also explains their often distorted and enlarged shape. Take this picture of the sun for example. -Mercury (magnitude +0.4) is deep in the glow of sunrise. It's having a very poor dawn apparition just above the eastern horizon. -Neptune (magnitude 7.9, in Aquarius) is barely emerging into view low in the east-southeast before dawn's first light. Both of these planets were hidden in the glare of the sun last week. Astro Picture of the Day: April 16, 2012 Source: From afar, the whole thing looks like an Eagle. A closer look at the Eagle Nebula, however, shows the bright region is actually a window into the center of a larger dark shell of dust. Through this window, a brightly-lit workshop appears where a whole open cluster of stars is being formed. In this cavity tall pillars and round globules of dark dust and cold molecular gas remain where stars are still forming. Already visible are several young bright blue stars whose light and winds are burning away and pushing back the remaining filaments and walls of gas and dust. The Eagle emission nebula, tagged M16, lies about 6500 light years away, spans about 20 light-years, and is visible with binoculars toward the constellation of the Serpent (Serpens). This picture combines three specific emitted colors and was taken with the 0.9 meter telescope on Kitt Peak, Arizona, USA. The famous pillars are seen at the centre of this nebula. |
Re: Terry's Astronomy Thread.
What's in the sky tonight?
April 17, 2012 -The eclipsing variable star Algol is at minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 10:44 p.m. EDT (9:44 p.m. CDT). This is the last chance till August to see Algol at minimum from the latitudes of the U.S. -Mercury (magnitude +0.4) is deep in the glow of sunrise. It's having a very poor dawn apparition just above the eastern horizon. -Keep careful watch on Saturn and its rings in a telescope. With Saturn at or near near opposition, notice the Seeliger effect: a temporary brightening of the rings with respect to the globe. This happens because the solid particles making up the rings backscatter sunlight (reflect it back in the direction it came from) more effectively than the planet's cloudtops do. Compare how the rings and globe look now with with how they look a week or more past opposition. By April 12th, three days before Saturn's opposition, the planet's rings had already brightened quite noticeably due to the Seeliger effect. South is up. A comparison image by the same photographer has been posted below. Astro Picture of the Day: April 17, 2012 Source: Antares is a huge star. In a class called red supergiant, Antares is about 850 times the diameter of our own Sun, 15 times more massive, and 10,000 times brighter. Antares is the brightest star in the constellation of Scorpius and one of the brighter stars in all the night sky. Located about 550 light years away, Antares is seen on the left surrounded by a yellowish nebula of gas which it has itself expelled. Radiation from Antares' blue stellar companion helps cause the nebular gas to glow. Far behind Antares, to the lower right in the above image, is the globular star cloud M4, while the bright star on the far right is Al Niyat. |
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