Astronomers put the red planet on red alert after predicting 1-in-75 odds for an asteroid to collide with Mars on or near January 30th. The asteroid, discovered in November 2007, is on a trajectory that poses no threat to Earth but has better-than-usual odds of packing quite a wallop for Mars. The impact, if it does happen, could take place on the equator, near the Opportunity rover’s stomping (or, perhaps, roving) grounds, though NASA says it would pose no risk to Opportunity. A crater as large as Arizona’s Meteor Crater could be carved out of the Martian surface by any direct hit that does happen. Scientists prepare to watch the event with keen interest, as this event would be potentially cataclysmic if Earth was in danger, but provides a once-in-a-lifetime opportunity for observation on Mars.