Cluster of Craters Caught on Mars
By Lisa Grossman May 5, 2011 | 3:27 pm | Categories: Space

Four fresh impact craters were recently spotted scarring Mars’ volcanic plains.
The new pockmarks were first noticed in August 2010, when the Mars Reconnaissance Orbiter’s low-res, grayscale Context camera saw a dark patch that hadn’t been there two years before.
Such new spots often come from impact craters left by meteorites. To confirm that, MRO’s sharp-eyed HiRISE camera went in for a closer look. While the Context camera takes wide-angles miles across, HiRISE zooms in to resolve objects the size of a beach ball.
The telephoto image revealed four distinct craters, each ringed with a dark blanket where soil was blasted out in the impact. The crater quartet could have been formed by a single meteorite that broke apart on its way through Mars’ atmosphere.
http://www.wired.com/wiredscience/2011/05/mars-impact-cluster/