The 2011 Geminid Meteor Shower
Dec. 13, 2011: The 2011 Geminid meteor shower peaks on the night of Dec. 13-14, and despite the glare of a nearly-full Moon, it might be a good show."Observers with clear skies could see as many as 40 Geminids per hour," predicts Bill Cooke of the NASA Meteoroid Environment Office. "Our all-sky network of meteor cameras has captured several early Geminid fireballs. They were so bright, we could see them despite the moonlight."
The best time to look is between 10 p.m. local time on Tuesday, Dec. 13, and sunrise on Wednesday, Dec. 14th. Geminids, which spray out of the constellation Gemini, can appear anywhere in the sky. "Dress warmly and look up," says Cooke. "It's that simple."
The source of the Geminids is near-Earth asteroid 3200 Phaethon. Most meteor showers come from comets, so having an asteroid as a parent makes the Geminids a bit of an oddball. Every year in mid-December, Earth runs through a trail of dusty debris that litters the orbit of 3200 Phaethon. Comets vaporizing in hot sunlight naturally produce such debris trails, but rocky asteroids like 3200 Phaethon do not. At least they're not supposed to. The incongruity has baffled researchers since 1983 when 3200 Phaethon was discovered by NASA's IRAS satellite.
One clue: 3200 Phaethon travels unusually close to the sun. The asteroid's eccentric orbit brings it well inside the orbit of Mercury every 1.4 years. The rocky body thus receives a regular blast of solar heating that might somehow boil jets of dust into the Geminid debris stream.
http://science.nasa.gov/science-news/science-at-nasa/2011/13dec_geminids/
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