​Ancient Mars Lake Found By Curiosity Rover​​

By:
December 10, 2021

An ancient Earth-like lake has been found on Mars by NASA’s Curiosity rover, providing more evidence that the planet may have supported life. The freshwater lake existed about 3.7 billion years ago, researchers said.

“Quite honestly, it just looks very Earth-like,” said Curiosity lead scientist John Grotzinger, of the California Institute of Technology in Pasadena. “You’ve got an alluvial fan, which is being fed by streams that originate in mountains, that accumulates a body of water,” Grotzinger told SPACE.com. “That probably was not unlike what happened during the last glacial maximum in the Western U.S.”

Scientists suggest that habitable environments were present on the Mars more recently than previously thought.

The lake once covered a small portion of the 96-mile-wide Gale Crater, which the 1-ton Curiosity rover has been exploring since touching down on the Red Planet in August 2012.

The main task of Curiosity’s $2.5 billion mission is to determine whether Gale Crater could ever have supported microbial life. The rover team achieved that goal months ago, announcing in March that a spot near Curiosity’s landing site called Yellowknife Bay was indeed habitable billions of years ago.

The new results, which are reported Monday, Dec. 9, in six separate papers in the journal Science, confirm and extend Curiosity’s landmark discovery, painting a more complete picture of the Yellowknife Bay area long ago.

This picture emerged from Curiosity’s analysis of fine-grained sedimentary rocks called mudstones, which generally form in calm, still water. The rover obtained powdered samples of these rocks by drilling into Yellowknife Bay outcrops.

The mudstones contain clay minerals that formed in the sediments of an ancient freshwater lake, researchers said. Curiosity also spotted some of the key chemical ingredients for life in the samples, including sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon.

The lake could have potentially supported a class of microbes called chemolithoautotrophs, which obtain energy by breaking down rocks and minerals. Here on Earth, chemolithoautotrophs are commonly found in habitats beyond the reach of sunlight, such as caves and hydrothermal vents on the ocean floor.

“It is exciting to think that billions of years ago, ancient microbial life may have existed in the lake’s calm waters, converting a rich array of elements into energy,” Sanjeev Gupta of Imperial College London, co-author of one of the new papers, said in a statement.