Among the rover’s other discoveries are rippling rock patterns, which show lakes occurred in an area of ancient Mars that scientists expected to be drier.
Scientists assumed they’d seen the last evidence of lakes covering this region of Mars when NASA’s Curiosity rover arrived at the “sulfate-bearing unit” last September.
NASA Discovers Evidence Of Lakes On Mars
This is due to the fact that the rock layers here originated in drier environments than the locations investigated earlier in the voyage. Sulfates, or salty minerals, are assumed to have been left behind when the area’s water dried to a trickle.
“This is the best evidence of water and waves that we’ve seen in the entire mission,” said Ashwin Vasavada, project scientist for Curiosity at NASA’s Jet Propulsion Laboratory in California.
Curiosity had previously discovered evidence of lakes covering portions of Mars in the salty minerals left behind when they dried up. Waves on the surface of a shallow lake stirred up material at the lake bottom billions of years ago, leaving rippling textures in the rock.
However, NASA scientists were startled to discover such clear signs of water in the Gale Crater, which the rover is currently exploring.
“We’ve climbed through many lake deposits during our mission but have never seen wave ripples this clearly,” Vasavada said in a statement.
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Layers Of History
Since 2014, the rover has been climbing the slopes of Mount Sharp, a 3-mile-high (5-kilometer-high) summit that was once riddled with lakes and streams that would have given a rich environment for microbial life, if any ever existed on Mars.
Mount Sharp is composed of strata, with the oldest at the bottom and the youngest at the summit. As the rover ascends, it moves along a Martian chronology, allowing scientists to examine how Mars developed from a more Earth-like world with a warmer climate and abundant water in its ancient past to the frigid desert it is today.
Curiosity discovered these wavy rock textures preserved over a half-mile above the mountain’s base in what’s known as the “Marker Band” – a narrow layer of dark granite that sticks out from the rest of Mount Sharp.
In the coming week, scientists will be seeking for softer rock. Even if they never receive a sample from this odd sliver of rock, they have other places they want to visit.
Scientists can see piece of evidence of the history of Mars’ old water in a valley called Gediz Vallis, which is far ahead of the Marker Band. The valley was created by wind, although a channel that runs across it and begins higher up on Mount Sharp is assumed to have been eroded by a tiny river.
Scientists believe wet landslides happened here as well, pushing car-sized stones and debris to the valley floor.
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