Terry's Astronomy Thread.

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Daily Suspicious0bserver's Weather Post:
July 6, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 6, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 7, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 7, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 8, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 8, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 9, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 9, 2014

Source:
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.



Daily Suspicious0bserver's Weather Post:
July 10, 2014

What's in the sky tonight?
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."

Astro Picture of the Day:
July 10, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 11, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 11, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 12, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 12, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 13, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 13, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 14, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 14, 2014

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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

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Daily Suspicious0bserver's Weather Post:
July 15, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 15, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 16, 2014

What's in the sky tonight?
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%.



Astro Picture of the Day:
July 16, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 17, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 17, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 18, 2014

What's in the sky tonight?
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%.

Astro Picture of the Day:
July 18, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 19, 2014

What's in the sky tonight?
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."

Astro Picture of the Day:
July 19, 2014

Source:
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 ...

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Daily Suspicious0bserver's Weather Post:
July 20, 2014

What's in the sky tonight?
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!

Astro Picture of the Day:
July 20, 2014

Source:
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.

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Daily Suspicious0bserver's Weather Post:
July 21, 2014

What's in the sky tonight?
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%.

Astro Picture of the Day:
July 21, 2014

Source:
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.

[Spenner]

Those sprites are really interesting/cool, something I really haven't heard of before. They look dazzling.

[Bluearrowll]

Sprite's are something I would love to capture a photo of - where you are located is almost perfect too. Head on over to the northern shores of Lake Ontario when there is a severe thunderstorm on the US side of the lake, and look above the storm. The lake is sufficiently dark even though you're in the middle of a large metropolis area, and because the storm is so far away you stay dry. Here's the source article about the sprites, it's a good read: http://www.fma-research.com/Papers&p...pr-view-1.html

Daily Suspicious0bserver's Weather Post:
July 22, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 22, 2014

Source:
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.

[Bluearrowll]

Daily Suspicious0bserver's Weather Post:
July 23, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 23, 2014

Source:
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.

[Bluearrowll]

Daily Suspicious0bserver's Weather Post:
July 24, 2014

What's in the sky tonight?
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.

Astro Picture of the Day:
July 24, 2014

Source:
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.

[Bluearrowll]

Daily Suspicious0bserver's Weather Post:
July 25, 2014

What's in the sky tonight?
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."

Astro Picture of the Day:
July 25, 2014

Source:
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.