Saturday, December 22, 2007

Asteroid May Hit Mars!

NASA just put out a press release announcing the possibility that an asteroid 164 feet (50 meters) across may slam into Mars next month. Based on the uncertainties in its trajectory, scientists are giving it a 1 in 75 chance of impact. The asteroid is traveling at about 30,000 miles per hour. If it hits Mars, the impact would release as much energy as three million tons of dynamite, and would leave a crater more than a half-mile wide.

It will be really interesting if this thing actually does impact Mars. There are enough spacecraft on and around the red planet that we would get some really interesting information about the effects of medium-sized impacts (not to mention some awesome pictures of the aftermath). A lot of the press releases have been comparing this potential impact with the Tunguska event: a large explosion over Siberia in 1908. This is misleading though, because the Tunguska event was likely caused by a mid-air explosion of an asteroid, rather than an impact into the surface. Since the explosion happened in mid-air, nobody is quite sure how large the impactor was. In fact, recent results show that it may have been only 20 meters across!

In any case, I find it pretty amazing that we are good enough at tracking rocks in space to be able to tell whether or not they will hit, not just the earth, but any other planet as well. This potential impact on Mars should also serve as a reminder that things like this can and do happen to earth too.

The Arecibo radar/radio telescope has been crucial in identifying and studying near-earth asteroids, but recently its funding for planetary radar was cut to save a few million dollars. Planetary radar is the best way to track potentially dangerous objects, and Arecibo is 20 times more sensitive than any other radar telescope. Arecibo's planetary radar could literally save the world, and it is being shut down to save money. To learn more, check out this statement from the Planetary Society.