NASA says asteroid (slightly) less likely to hit Mars | NetworkWorld.com Community

NASA lengthens the odds on the asteroid hitting Mars

The calculation was 1 in 25, is now 1 in 28. The big event occurs Jan 30th. Scientists will be able to sharpen the estimates when the asteroid becomes observable again (soon).

Given the lack of atmosphere on mars, the object could crash into the planet at a speed of some 30,000 MPH. That would be about equivalent to a three megaton bomb, and could leave a crater a half-mile wide. That's big, but not stupendous.