> At least one object streaked across the early morning sky and shattered 10 km over the city of Chelyabinsk.<p>This bungled account shows the risk in trying to report unfolding events in an encyclopedia. In fact, the meteor(s) didn't "shatter" over Chelyabinsk -- it (or they) remained intact and are reported to be located in a crater west of the city. This outcome is predictable by watching the videos and noticing that the paired contrails continue past the point of maximum brightness. That brightest point is the point of maximum energy release and deceleration. If you witness a meteor brighten, then dim, but continue to show a path and a contrail after that point, you can be sure it (or its fragments) will reach the ground.<p>It is most likely that this was a metallic meteorite, because most stony meteorites disintegrate before reaching the ground.