The Curiosity Rover of the National Aeronautics and Space Administration (NASA) has found fresh proof that an old lake once existed in a location of Mars that was previously thought to be dry.

News reports say that the rover was moving through a region of Mars known as the "sulfate-bearing unit," which scientists had predicted would have only "tiny trickles of water" due to the theory that the rocks there developed as the surface of the red planet dried out.

Instead, they discovered some of the oldest waters that were the purest.

“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 NASA’s Jet Propulsion Laboratory in Pasadena, California, in a statement. “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.”