Chelyabinsk: An Ordinary Chondrite From a Spectacular Fall in Russia

The asteroidal explosion that occurred over Chelyabinsk, Russia on Feb 15, 2013 was the first-witnessed occurrence that caused significant damage to humans and their properties. The bolide responsible for this extraordinary event was estimated to be 17-20 m in diameter, traveling at a speed of ~18 km/s. Although it coincided with the fly-by of 2012DA_(14) (a ~45 m asteroid), the Chelyabinsk bolide has been estimated to be derived from the main asteroid belt. Here, we report our study of two pieces of this meteorite, both completely covered by fusion crust and amounting to a total mass of ~5 g.