Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift.
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SOLAR SAIL SIGHTINGS: NASA's first Earth-orbiting solar sail, NanoSail-D, is making a series of passes over North America this week. It's not very bright--that is, until it flares. Photograph one of those outbursts and you might win $500. Flyby predictions may be found on the web or on your cell phone. Good luck!
APPROACHING ACTIVE REGION: A significant active region is set to emerge over the sun's northeastern limb. The underlying sunspots are not yet visible from Earth, but the region's towering magnetic canopy is already in view. NASA's Solar Dynamics Observatory (SDO) took this picture during the early hours of Feb. 23rd:
A better view is had by NASA's STEREO-B probe, stationed over the sun's eastern limb where it can see the region from top down. Recent movies beamed back by STEREO-B show flashes of extreme UV radiation and hints of magnetic instability. This could herald a period of renewed solar activity when the region turns toward Earth in the days ahead. Or the action could peter out beforehand. Stay tuned for updates.
FIND THE ICE: Not all the ice in this picture is on the rocks. Some of it is in the air. Airborne ice crystals caused the luminous sun pillar witnessed yesterday at sunset by Bryan Hansel on the shores of Lake Superior:
"Just after the sun set, a tall pillar appeared over the lake," says Hansel. "As we watched, we could see icy clouds moving through the column of light."
In the northern hemisphere, February is a good time of year to see this phenomenon. Flat six-sided crystals flutter down from the clouds like leaves falling from trees. Aerodynamic friction tends to align their flat faces parallel to the ground. When low sunbeams hit all those icy mirrors, voila!--a sun pillar. Look for them at sunrise or sunset.
February 2011 Aurora Photo Gallery
[previous Februaries: 2010, 2009, 2008, 2007, 2006, 2004, 2003, 2002]
NanoSail-D Photo Gallery
[NASA: Solar Sail Stunner] [Photo Contest]
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 February 23, 2011 there were 1198 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 |
| ||for out-of-this-world printing and graphics |