The National Aeronautics and Space Administration's (NASA) news service provides this report on the composition of the meteor that put on a brilliant sky show before landing in Western Canada this January. The fragments of the meteorite fell into a frozen lake, so they were not recovered for study until the lake began to thaw this April. Analyses of the pieces that were recovered suggest that the fallen object had a relatively rare composition and was "...about seven meters across and 200 to 250 metric tons. This wasn't your average meteoroid -- it was basically a C-class asteroid detonating in the atmosphere over the Arctic!" says Dr. Peter Brown of the University of Western Ontario. Visit the site for the full report.