iPHONE VS ANDROID! Actually, it doesn't matter which phone you carry. Our cool, new app turns both smartphones into field-tested satellite trackers. Learn more.
| || |
GREEN SNOW: Globally, Earth's magnetic field was quiet over the weekend, but in one corner of northern Canada the story was different. "On Saturday night," reports Francis Anderson, "the auroras here in Tuktoyaktuk of the Northwest Territories were so bright they cast shadows on the ground and [turned the snow green]!" The phenomenon is called a "substorm" and it gives reason for people of the North to keep an eye on the sky even when the global forecast calls for quiet. more images: #1, #2, #3.
UPDATE! The "mega-filament" described below has just erupted. NASA's Solar Dynamics Observatory made a must-see movie of the epic blast. The eruption does not appear to be geoeffective; Earth-effects might be limited to pretty pictures.
MEGA-FILAMENT: A magnetic filament snaking around the sun's SE limb just keeps getting longer. The portion visible today stretches more than 700,000 km--a full solar radius. NASA's Solar Dynamics Observatory took this picture during the early hours of Dec. 6th:
NASA's STEREO-B spacecraft, stationed over the sun's eastern horizon, saw this filament coming last week. So far the massive structure has hovered quietly above the stellar surface, but now it is showing signs of instability. Long filaments like this one have been known to collapse with explosive results when they hit the stellar surface below. Stay tuned for action.
more images: from Dave Tyler of Buckinghamshire UK; from Deirdre Kelleghan of Bray, Co Wicklow, Ireland; from Peter Desypris of Athens,Greece; from Robert Arnold of Isle of Skye, Scotland; from Cai-Uso Wohler of Bispingen, Germany; from Gianfranco Meregalli of Milano, Italy; from Francisco A. Rodriguez of Cabreja Mountain Observatory, Canary Islands; from Larry Alvarez of Flower Mound, Texas;
THE SHADOW OF EARTH: Imagine stepping out your front door and being swallowed up by the vast dark shadow of an entire planet. Actually, you've done it many times. The darkness you experience after sunset is the shadow of Earth itself. (Think about it.) If you happen to be outside right at sunset, you can sometimes catch Earth's shadow rising to extinquish the twilight. That's exactly what happened to Andrew Greenwood yesterday in England's Peak District National Park:
"I was climbing towards a hill known as Shining Tor when I broke through the fog into the most magical sunlit landscape," says Greenwood. "With the clouds below me, the air was crisp and ultra-transparent. It was at this point that I noticed Earth's shadow climbing into the ice-blue sky in the East. This spectacular vision is sometimes called the 'Belt of Venus.' Its contrast against the snow-covered hills was breath-taking; I could not have wished for a more memorable end to what was in fact my 38th birthday!"
more images: from Börkur Hrólfsson of Gullfoss, Iceland.
November 2010 Aurora Gallery
[previous Novembers: 2009, 2008, 2007, 2006, 2004, 2003, 2002, 2001, 2000]
Potentially Hazardous Asteroids (PHAs
) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones
all the time.
On December 6, 2010 there were 1167 potentially hazardous asteroids. Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.
| ||The official U.S. government space weather bureau |
| ||The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| ||Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. |
| ||3D views of the sun from NASA's Solar and Terrestrial Relations Observatory |
| ||Realtime and archival images of the Sun from SOHO. |
| ||from the NOAA Space Environment Center |
| ||the underlying science of space weather |