NASA's Curiosity Mars rover has photographed rocks imprinted with tiny ripples from an ancient lake. And these tiny ripples are making waves on Earth, as they are the clearest evidence yet that water once existed on the Red Planet.
The ripple marks were discovered frozen in Martian rock on the slopes of Mount Sharp. Though Curiosity has traversed many rock deposits laid down in ancient lakes, scientists had not seen such vivid marks in the rocks before.
"This is the best evidence of water and waves that we've seen in the entire mission," Ashwin Vasavada(opens in new tab), Curiosity’s project scientist at NASA's Jet Propulsion Laboratory in Southern California, said in a statement(opens in new tab). "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."