Astronomers at NASA's Near Earth Object program are keeping close watch on asteroid 2007 WD5. This asteroid is estimated to be 50 meters wide, and will cross Mars' orbit early in 2008. Archival imagery has recently allowed astronomers to more accurately describe its trajectory, which until recently was largely uncertain. Current models predict a 1 in 25 chance that asteroid 2007 WD5 will impact Mars on January 30th, 2008, at a speed of about 27,900 miles per hour.
Image Courtesy of NASA/JPL-Caltech.
In this image, each of the yellow dots represents a possible location for Asteroid 2007 WD5 on January 30th, 2008. Note that some of the dots are on Mars' surface. This belt of possible impact regions lies just north of where the Mars rover Opportunity is currently exploring Victoria Crater.
If this asteroid were to impact Mars, it would leave a crater larger than a half-mile wide, about the size of Victoria Crater. In such an event, we could possibly see footage of the impact from the Mars rovers, and from ground and space-based telescopes. This may be the next Shoemaker-Levy 9, or it could be a dud. Only time will tell.