a trail of clouds in the sky created by a meteorite falling to Earth Alex Alishevskikh On the morning of Feb. 15, 2013, a meteor fell to Earth over Chelyabinsk, Russia. The resulting meteorites were of a certain type that until now didn't have an obvious near-Earth asteroid source. (Creative Commons license: https://creativecommons.org/licenses/by-sa/2.0/deed.en)