NASA’s Curiosity rover rolls past evidence of ancient water

NASA's Curiosity Mars rover captured this view of layered, scaly rocks thought to have formed in an old stream bed or small pond.

For the past 10 years, the Curiosity rover has traveled across the Martian realm in search of clues the potentially habitable past of the planet. Recently, the car-sized robot drove through a transition zone, moving from an area that may have once held lakes on the surface to one that means drier conditions for the Red Planet.

NASA’s Curious Rover noticed the change of scenery higher up on a Martian peak that the robot has been climbing since 2014. 5-kilometer-tall Mount Sharp is the central peak in Mars’ Gale Crater, which is also the rover’s search for signs of ancient water. At the foot of Mount Sharp, Curiosity collected evidence of clay minerals formed from lakes and streams that once flowed through Gale Crater. But higher up the mountain, those streams had seemingly dried up to rivulets and sand dunes that had formed over the lake’s sediments.

Characterized by a shift from a clay-rich region to one filled with the salty mineral sulfate, this so-called transition zone could potentially signify a major shift in Martian climate that occurred billions of years ago. The higher Curiosity gets on Mount Sharp, the less clay and more sulphate are discovered. Curiosity will soon begin drilling the final rock sample collected in the transition zone in hopes of learning more about the alteration in the mineral composition of the rocks in the area.

“We’re no longer seeing the lake deposits that we saw deeper at Mount Sharp for years,” Ashwin Vasavada, Curiosity’s project scientist at NASA’s Jet Propulsion Laboratory, said in a NASA press release. “Instead, we see a lot of evidence of drier climates, like dry dunes that were occasionally lapped by streams. This is a big change from the lakes, which may have existed for millions of years before.”

The Curiosity rover captured this panorama of a sulfate-bearing region on Mars.

The Curiosity rover captured this panorama of a sulfate-bearing region on Mars.
picture: NASA/JPL-Caltech/MSSS

The area Curiosity is currently exploring also features hills that may have formed under dry conditions, and those hills are marked by large, windswept sand dunes that likely hardened into rocks over time, according to NASA. Meanwhile, the rover also found evidence of sediment being carried through the sand dunes by water currents. These sediments now appear as stacked layers of flaky looking rocks.

Although Mars is a desolate, arid planet today, scientists believe in it may have once been habitable and hosted lakes and other bodies of water on its surface. early in its history, Mars somehow lost some of its atmosphere and its water dried up. Various robot Missions from NASA and other space agencies have worked to piece together this ancient story. A more recent Mars rover, Perseverance, landed on the planet in February 2021 and did Search for microfossils– preserved evidence of ancient microbial life.

It is approaching its 10th anniversary Anniversary on Mars Curiosity shows first signs of aging. On June 7, according to NASA, Curiosity entered the dreaded safe mode when a temperature reading indicated warmer than usual temperatures. The rover was back in action two days later, but NASA engineers are still investigating the cause of the problem and hope it won’t affect the rover’s operations as it climbs to the forefront of a new era in Martian history.