Mars-Asteroid Collision?

Astronomers tracking Near-Earth Objects at NASA's JPL have recently found an asteroid that has a 1-in-75 chance of slamming into Mars January 30, 2008. Those odds are far higher than normal impact possibilities for any planet.

The asteroid in question seems to be roughly the size of the Tunguska object that exploded in the atmosphere over Siberia in 1906. Mars' atmosphere is not nearly as dense as Earth's, however, so if this body is on target, it will almost certainly reach the surface, creating a crater perhaps a half-mile wide. With all the scientific missions now operating at Mars, such an event would be extremely well documented.

This would be the second prominent planetary collision in fifteen years. In 1994, Comet Shoemaker-Levy plowed into the atmosphere of Jupiter. Even if this asteroid misses Mars, which is the likeliest outcome, the collision at Jupiter and a close brush at Mars, combined with documented near misses of Earth and the stark, mute testimony of pounding on the surfaces of Mars and Earth's Moon argue a space capability to deflect bodies away from Earth is essential to human survival.