Observations by NASA’s Curiosity Rover indicate Mars’ Mount Sharp was built by sediments deposited in a large lake bed over tens of millions of years. This interpretation of Curiosity’s finds in Gale Crater suggests ancient Mars maintained a climate that could have produced long-lasting lakes at many locations on the Red Planet.
“If our hypothesis for Mount Sharp holds up, it challenges the notion that warm and wet conditions were transient, local, or only underground on Mars,” said Ashwin Vasavada, Curiosity deputy project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “A more radical explanation is that Mars’ ancient, thicker atmosphere raised temperatures above freezing globally, but so far we don’t know how the atmosphere did that.” [More at link]