February 15, 2013
On Friday morning (Feb.15), residents of Russia’s Chelyabinsk region were shocked by a giant fireball streaking across the sky. The explosion, caused by a small meteoroid entering the atmosphere, reportedly injured hundreds as it blew out windows and sent glass flying.
Dozens of videos of the meteor trail and its aftermath quickly appeared online, and analyses of these eyewitness accounts as well as measurements from scientific instruments are giving scientists one of the best looks ever at an atmospheric meteor burst.
Here are some frequently asked questions about the meteor event and what its known so far.
1. How big was it?
Calculations are preliminary, but NASA has found this is the largest meteor since the Tunguska event in 1908, which flattened hundreds of acres of remote forest in Siberia.