Taking before and after pictures of Martian terrain, researchers of the UA-led HiRISE imaging experiment have identified almost 250 fresh impact craters on the Red Planet. The results suggest Mars gets pummeled by space rocks less frequently than previously thought, as scientists relied on cratering rates of the moon for their estimates.
Scientists using images from NASA’s Mars Reconnaissance Orbiter, or MRO, have estimated that the planet is bombarded by more than 200 small asteroids or bits of comets per year forming craters at least 12.8 feet (3.9 meters) across.
Researchers have identified 248 new impact sites on parts of the Martian surface in the past decade, using images from the spacecraft to determine when the craters appeared. The 200-per-year planetwide estimate is a calculation based on the number found in a systematic survey of a portion of the planet. (more…)