NASA experts say the risk of an asteroid smashing into Mars is higher than they previously thought. Last week the agency said the probability of asteroid 2007 WD5 hitting the red planet was 1.3%. After further number crunching it now says it is more like 3.9% (press release).

Although this is an unusually high percentage, it is still most likely that WD5 will miss the planet.

This is going to upset Don Yeomans, head of the agency’s Near-Earth Object Program. He told Fox News he was looking forward to a smash. “I think it’ll be cool. Usually when an asteroid is headed toward Earth, I’m not rooting for an impact,” he said.

Set your alarms though: “In the unlikely event of an impact, the time would be 2008 January 30 at 10:56 UT (2:56 a.m. PST) with an uncertainty of a few minutes,” says NASA.

See also

Great Beyond on the original announcement

Slashdot on the shortening odds:

“At this rate, the impact’s likelihood will exceed 150% in just a few days.”

“Actually, Murphy’s law says that not only will the asteroid miss Mars, it says that the asteroid miss will be precisely enough to whip the rock around to a new orbit. One precisely timed and angled to aim it towards Earth where it will impact on some particularly inconvenient location.”

NASA on the original announcement

Animation of bodies involved (thin white line = orbit of Mars; blue line = motion of the centre of the uncertainty region, which is the most likely position of the asteroid)

Image: composite image of the planet Mars taken by Hubble Space Telescope / NASA