NASA's Curiosity rover has discovered the "clearest evidence yet" of ancient water ripples formed within lakes, according to the Jet Propulsion Laboratory (JPL).
"Billions of years ago, waves on the surface of a shallow lake stirred up sediment at the lake bottom, over time creating rippled textures left in rock," said the JPL, NASA's federally-funded research and development center.
The rover has been exploring Mars since 2012 and sending back pictures of rippled patterns on the surface of the red planet.
"This is the best evidence of water and waves that we've seen in the entire mission," said Ashwin Vasavada, Curiosity's project scientist at JPL. "We climbed through thousands of feet of lake deposits and never saw evidence like this-and now we found it in a place we expected to be dry."
Since 2014, the rover has been ascending the foothills of Mount Sharp, a 3-mile (5-kilometer) mountain that was once laced with lakes and streams that would have provided a rich environment for microbial life, according to the JPL.
