I don’t know if anybody saw anything plunging through the atmosphere tonight, but we were due for an atmospheric reentry of some space trash which has been orbiting for over a year since being tossed overboard. The ammonia tank was tossed during a July 23, 2007 spacewalk.
NASA expects up to 15 pieces of the tank to survive the searing hot temperatures of re-entry, ranging in size from about 1.4 ounces (40 grams) to nearly 40 pounds (17.5 kg).
If they reach all the way to land, the largest pieces could slam into the Earth’s surface at about 100 mph (161 kph). But a splashdown at sea is also possible, as the planet is two-thirds ocean.
“If anybody found a piece of anything on the ground Monday morning, I would hope they wouldn’t get too close to it,” Suffredini said.
Nothing to worry about. So, a rough back of the envelope calculation has the largest piece possibly slamming down with only 17499 Joules of energy. This is roughly the same kinetic energy of a 2000 Kg car at about 9-10 mph. But as the article states, the highest likelihood is for an ocean hit.
But on a related note, space trash is a pretty serious problem. Check out The Center for Orbital and Debris Studies. There’s a cool picture of all the trash being tracked with a link to a QuickTime animation. And I thought my desk was a mess.