Update: In case you’re wondering where Chelyabinsk is.
Update: The Guardian reports more than 950 injuries.
To put all this in some perspective, the asteroid that will buzz us today is about the same size as the object that struck Tunguska in 1908 — about 220 million pounds, more or less. The afterglow from that strike was visible across Europe. The asteroid that actually struck in Chelyabinsk today was probably only about 10 tons. A speck, by space standards. But it struck at about 33,000 miles per hour. Most of it burned up in the atmosphere, and the friction and pressure in the atmosphere caused it to explode during its descent. Most of it never reached the ground.
If the near-miss asteroid was on a slightly different trajectory and entered the earth’s atmosphere, most of it would burn up too, but it could still wipe out a city.
Update: So, how close will Asteroid 2012 DA14 actually get to earth today? Astronomers say it will pass within about 17,000 miles of us. Our GPS satellites orbit at about 12,000 miles. Most geostationery satellites orbit at about 22,000 miles up. So 2012 DA14 will pass within the orbits of those man-made satellites, and well within the Moon’s orbit. So, in space terms, way too close. But not close enough to do any damage.
Update: I just found this video of the Russia impact on YouTube. You can hear the explosion and even glass shattering.
Update: I bet these folks are fielding a lot of calls today.
Obama announces he won’t build a Death Star, and an asteroid hits the Earth? Even aliens don’t respect his foreign policy.
— Brodigan (@brodigan) February 15, 2013
Also read: Russian Army Finds Space Rock Impact Sites