A little over a month from now, Mars might be hit by an asteroid! There’s a 1 in 75 chance (due to uncertainties about the exact trajectory), according to the people tracking the object’s progress right now. The 50 metre wide object is due to pass within 300000 miles of Mars at about 6 a.m. EST (3 a.m. PST) on Jan. 30, 2008. Quoting quite a bit from the press release from JPL/NASA:
Asteroid 2007 WD5 was first discovered on Nov. 20, 2007, by the NASA-funded Catalina Sky Survey and put on a “watch list” because its orbit passes near Earth. Further observations from both the NASA-funded Spacewatch at Kitt Peak, Ariz., and the Magdalena Ridge Observatory in New Mexico gave scientists enough data to determine that the asteroid was not a danger to Earth, but could potentially impact Mars. This makes it a member of an interesting class of small objects that are both near Earth objects and “Mars crossers.”
Because of current uncertainties about the asteroid’s exact orbit, there is a 1-in-75 chance of 2007 WD5 impacting Mars. If this unlikely event were to occur, it would be somewhere within a broad swath across the planet north of where the Opportunity rover is located.
[Update: 2th December - the chances have been increased to 1 in 25. See the updated press release (linked above)....]
[Update: 9th January - the chances had decreased to 0.0. See the updated press release.]
(Thanks, Nick W.!)