“Observations from the Curiosity rover suggest that a series of long-lived streams and lakes existed at some point between about 3.8 to 3.3 billion years ago,” said Ashwin Vasavada, Mars Science Laboratory project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif, and co-author of the article.
As Curiosity explored the Gale Crater on Mars, it found evidence of many different layers of sediment. These layers of sediment were left behind by lakes and now form the base of Mount Sharp.
It is theorized that the lakes disappeared, evaporating into the atmosphere.
“It’s clear that the Mars of billions of years ago more closely resembled Earth than it does today. Our challenge is to figure out how this more clement Mars was even possible, and what happened to that wetter Mars,”said Michael Meyer, one of NASA’s lead scientists.
But where did the water come from?
“We have tended to think of Mars as being simple,” John Grotzinger, the lead author of the report said. “We once thought of the Earth as being simple too. But the more you look into it, questions come up because you’re beginning to fathom the real complexity of what we see on Mars. This is a good time to go back to reevaluate all our assumptions. Something is missing somewhere.”