Explosive crater twins on Mars

11 April 2013 - Dramatic underground explosions, perhaps involving ice, are responsible for the pits inside these two large martian impact craters, imaged by ESA's Mars Express on 4 January. The 'twin' craters are in the Thaumasia Planum region, a large plateau that lies immediately to the south of Valles Marineris, the largest canyon in the Solar System. The northernmost (right) large crater in this scene was officially given the name Arima in early 2012, but the southernmost (left) crater remains unnamed. Both are just over 50 km wide and display intricate interior features. The southernmost crater is also presented here in a perspective view, revealing its complex characteristics in detail. Multiple terraces slump from the crater walls onto a flat floor, but perhaps the most striking feature is the central pit, a feature it shares with Arima crater to its north. Central pit craters are common on Mars, as well as on the icy moons orbiting the giant planets in our Solar System.