By now, you're probably familiar with the meteor that exploded in the earth's atmosphere on Friday. About 930 miles east of Moscow, in remote Chelyabinsk, a speeding space rock hurtled through the sky, injuring over 1,000 Russians (and frightening the rest of the world, once video was uploaded by eye witnesses). And the Russian meteor wasn't even the asteroid we were expecting.

But what, scientifically speaking, really happened? Scientists are beginning to piece together the details of the Russian meteor explosion, which they say was the biggest event since the Tunguska impact of 1908. That year, a 150-foot, 100,000-ton meteor exploded over Siberia, razing 800 square miles and 80 million trees.