Image: Vapour trail of the 2013 Chelyabinsk asteroid

Vapour cloud trail left by the Chelyabinsk asteroid as seen by M. Ahmetvaleev on 15 February 2013.

It shows the path where an approximately 20 m-diameter, 13 000-tonne (and previously unknown) near-Earth object (NEO) entered Earth's atmosphere over the city of Chelyabinsk in Russia.

The small asteroid exploded at a height of about 30 km, generating a bright, hot explosion with a gas cloud, as well as a large shock wave that broke windows and knocked down parts of buildings and structures. Subsequent media reports said some 1500 people were injured by flying glass and other debris, although no deaths were reported.

In 2015, former Apollo astronaut Rusty Schweickart described the event in this Asteroid Day blog post.