Asteroid's Martian Impact: What Might Happen

The possibility of an asteroid walloping the planet Mars this month is whetting the appetites of Earth-bound scientists, even as they further refine the space rock's trajectory.

The space rock in question — Asteroid 2007 WD5 — is similar in size to the object that carved Meteor Crater into northern Arizona some 50,000 years ago and is approaching Mars at about 30,000 miles per hour (48,280 kph).

Whether the asteroid will actually hit Mars or not is still uncertain.

But if WD5 does smack into Mars, some astronomers have a fair idea of what havoc it may spawn. The likely strike zone would be near the equator, but to the north of the current position of NASA's Opportunity rover

The collision, were it to occur, could also create a visible dust plume as ejecta is lofted high into the martian atmosphere, he said.

The resulting crater could reach more than a half-mile (0.8-km) in diameter

http://www.space.com/scienceastronom...le-impact.html