The deepest canyons on Mars were rapidly formed by devastating floods

By Leah Crane

Floods may have been far more important on ancient Mars than we thought. The Red Planet is criss-crossed by valley networks that once held flowing rivers and the deepest of them seem to have formed quickly from cataclysmic flooding.

Up until about 3.5 billion years ago, many of the craters that pock the Martian surface were full of water. Timothy Goudge at the University of Texas at Austin and his colleagues mapped out how often those …