Martian impact crater or supervolcano caldera

Paris (ESA) May 25, 2015
At first glance, the region covered by this latest Mars Express image release appears to be pockmarked with impact craters. But the largest structure among them may hold a rather explosive secret: it could be remains of an ancient supervolcano. The images presented here were taken by the high-resolution stereo camera on ESA’s Mars Express on 26 November 2014, and focus on the Siloe Patera
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