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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WEEKEND METEOR SHOWER: Today Earth is entering a stream of debris from Halley's comet, source of the annual Orionid meteor shower. Forecasters expect the shower to peak on Saturday morning, Oct. 22nd, with more than 15 meteors per hour. Observing tips: Wake up before dawn, get away from city lights, and look up at the glittering stars of Orion, Taurus and Gemini. That's the backdrop for the display. Also, the crescent Moon, Mars and Regulus will form a triangle in the eastern sky to admire during lulls in the shower. [full story] [meteor radar] [live counts]
LAST-CHANCE SIGHTINGS OF ROSAT: The massive ROSAT X-ray space telescope is making its final spiralling orbits around Earth. Most experts agree that re-entry will occur during the early hours of Oct. 23rd over a still-unknown region of our planet. Meanwhile, the satellite can still be seen slicing brightly through the night sky. On Oct. 20th, Dennis Mammana photographed it from Borrego Springs, California:
"Farewell ROSAT!" says Mammana. "The Röntgen Satellite moved quite fast as it made one its final visible passes over Southern California's Anza-Borrego Desert. I caught it on its way into Earth's shadow using a Nikon D700 digital camera."
Although Mammana noted that satellite was faint, others have seen it glowing more brightly than a first magnitude star. Derek Breit of Morgan Hill, California, witnessed a brilliant flare on Oct 18th, which he recorded in this 14 MB video. The increase in brightness was probably caused by sunlight glinting off one of ROSAT's flat surfaces.
Want to see ROSAT one last time? Check Spaceweather's Satellite Tracker for flyby times. You can also turn your smartphone into a field-tested ROSAT tracker.
According to the DLR (the German space agency), which operated the observatory while it was active in the 1990s, as many as 30 pieces of debris could reach Earth's surface. Of particular concern is the telescope's heat-resistant mirror assembly — 1.6 metric tons in all — which could hit the ground intact at hundreds of miles per hour. Odds favor an ocean splashdown or a land impact in sparsely inhabited wilderness.
ROSAT images: from Jim Turney of Cold Springs Valley, Nevada, USA; from James Beauchamp of Oklahoma City, OK; from Thierry Legault of Paris, France; from Dewey Vanderhoff of Cody, Wyoming , USA; from Olivier Staiger of Crans-Montana Switzerland
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 October 21, 2011 there were 1256 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 |
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