Ripples Reveal Ancient Global Megafloods on Mars

by Ryan Whitwam

Mars is a mostly dry, dusty planet these days, but the more we study it, the more we learn about its watery past. Very watery, it would seem. New findings from the Curiosity rover point to megafloods in the planet’s past. NASA couldn’t see the evidence of this event from space, but Curiosity was able to make the determination by scanning Martian geology from the surface.

Curiosity has been on Mars since 2012, using an array of instruments to photograph, sample, and analyze little bits of Mars. The team from Jackson State University, Cornell, NASA’s Jet Propulsion Laboratory (JPL), and the University of Hawaii used data from the Mars Hand Lens Image (MALI) and Mastcam cameras to detect features in Gale Crater called megaripples. These features are identical to features formed by melting ice on Earth about 2 million years ago.

According to the new study, megaripples are large geological formations consisting of sediment deposited in wave-like ripples. A catastrophic flash flood is the only event scientists know of which can produce such features. The team believes that at some point after Gale Crater formed, an even larger object impacted Mars. This hypothetical impact released enough heat to melt ice deposits on the planet, along with releasing huge volumes of carbon monoxide and methane.