| LUCKY AURORAS: Friday the 13th could be a lucky day for Arctic sky watchers. A solar wind stream is heading for Earth, and NOAA forecasters estimate a 30% chance of geomagnetic activity when it arrives on March 13th. Stay tuned for Northern Lights at the end of the week: gallery. COSMOS IS FALLING: The first fragments of shattered satellite Cosmos 2251 are about to reenter Earth's atmosphere. According to US Strategic Command, fragment 1993-036PX will reenter on March 12th, followed by 1993-036KW on March 28th and 1993-036MC on March 30th. These are probably centimeter-sized pieces that will disintegrate in the atmosphere, posing no threat to people on the ground. Cosmos 2251 was shattered on Feb. 10th when it collided with Iridium 33. Cosmos 2251 possessed almost twice the mass of Iridium 33 and to date appears to have produced more than twice the number of fragments. Click on the image to view a map of the debris orbits: 
"As of March 7th, there were 355 catalogued fragments of Cosmos 2251 and 159 fragments of Iridium 33," says Daniel Deak who prepared the orbit-map. "The Cosmos fragments are not only more numerous, but also more widely scattered, ranging in altitude from 198 km to 1689 km. For comparison, Iridium fragments are confined to altitudes between 582 km and 1262 km." The extra scatter of Cosmos debris is not fully understood. Impact geometry could explain the spread, but no one knows exactly how the two complex vehicles struck one another. A factor of possible importance: Cosmos 2251 was internally pressurized. Once ruptured, it may have blown itself apart. The International Space Station is in no immediate peril. "NASA has recognized from the first day [of the collision] that the risks to both ISS and STS-119 have increased," says Nick Johnson, Chief Scientist for Orbital Debris at the Johnson Space Center. "However, those increases have been relatively minor in comparison to the background environment." Updated debris maps: #1, #2, #3, #4, #5. WORM MOON RISING: According to folklore, this week's full Moon has a special name--the Worm Moon. It heralds the coming of northern spring and the first stirring of earthworms in thawing garden soils. Keith Breazeal photographed the "worm moonrise" last night near Lake Tahoe, California: 
"What a view it was as it rose against the tree line just after sunset," says Breazeal. "I took the picture using my Canon 40D." more images: from Mark and Nancy Staples of Santa Fe, New Mexico; from Doug Zubenel of Cedar Creek near De Soto, Kansas; from Tamas Ladanyi of Veszprem, Hungary; from Elias Chasiotis of Markopoulo, Greece; from Abraham Tamas of Zsámbék, Hungary; from Honor Wheeler of Wilmington, Kent, UK; from Thad V'Soske at the Colorado National Monument, Colorado; from Aymen Ibrahem of Bibliotheca Alexandrina, Alexandria, Egypt; from Christopher Calubaquib of El Sobrante, California; from Rob Kaufman of Castlemaine, Victoria, Australia; from Fredrik Broms of Kvaløya, Norway;
March 2009 Aurora Gallery
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