Daily Suspicious0bserver's Weather Post:
January 18, 2014
What's in the sky tonight?
January 18, 2014
-This the Big Dipper's time of year to swing up from the low north-northeast after dusk, to stand on its handle in the northeast by about 9 p.m.
-Jupiter's Great Red Spot transits Jupiter's central meridian around 10:15 p.m. EST.
-A minor CME expected to hit Earth's magnetic field on Jan. 17th is late, but NOAA forecasters still think it is coming. They estimate a 40% chance of polar geomagnetic storms on Jan. 18th in response to the tardy impact. High-latitude sky watchers should be alert for auroras.
-Luminous halos around the Moon are nothing unusual, especially in wintertime Finland where the air is so often filled with ice. Crystals of frozen H2O catch the moonlight and bend it into a circular ring of light. A few nights ago, however, Sauli Koski of Muonio, Finland, witnessed a halo that was not circular, but elliptical.
"On Jan. 15th, the weather changed. As the temperature dropped from -7C to -37C, there were all kinds of ice halos to photograph," says Koski. "The best and rarest were these elliptical forms that lasted more than 20 minutes."
Although physicists have been studying ice halos for decades, not all are understood. "Elliptical halos are one of the puzzles," says atmospheric optics expert Les Cowley. " We can simulate them by invoking hexagonal plate-like crystals topped by almost flat pyramid faces. However, the simulations do not fit very well and such crystals are unphysical. Crystal facets like to form along planes where there are lots of atoms or molecules – almost flat pyramids do not fit the bill at all. Perhaps some peculiar distorted snowflake types instead?"
"These mysteries all add to the spice of halo observing, the beautiful, the unexpected, the unexplained, something new!"
-A sunspot approaching from just behind the sun's southeastern limb is crackling with solar flares. The explosions are registering C2 to C8 on the Richter Scale of Flares even though they are partially eclipsed by the edge of the sun. In Athens, Greece, amateur astronomer Peter Desypris photographed the flying debris from one of the explosions.
"Indeed, something big appears to be on the way," says Desypris.
The sun's rotation is slowly turning the active region toward Earth. During the weekend its core should emerge into plain view for a better evaluation of its flare-producing potential. Stay tuned for updates.
Astro Picture of the Day:
January 18, 2014
Source:
This big, bright, beautiful Full Moon rose over Lick Observatory Wednesday night. Traditionally a full moon in January might be called the Wolf Moon. But this moon reached its full phase on January 16, 4:54 UT, within about 2 hours of apogee, the most distant point in its elliptical orbit around planet Earth. That also makes it the smallest full moon of 2014. Of course the difference in apparent size between the largest and smallest full moons is hard to see, because the difference in distance between lunar apogee and perigee, or closest point in the Moon's orbit, is only about 50,000 kilometers, while the Moon's average distance is around 385,000 kilometers. Though not by much, this apogee's full moon was also the smallest full moon of the last 1,000 years. It will keep that distinction until a slightly smaller full moon occurs close to apogee in 2154.