Signs that Perseverance is moving down an ancient mighty river

May 11. (EUROPE PRESS) –

New images from NASA’s Perseverance rover show signs of what was once a river on Mars, one deeper and faster of all the previous evidence collected on the red planet.

The river was part of a network of waterways that emptied into Jezero Crater, the area the rover has been exploring since it landed more than two years ago.

Understanding these aqueous environments could help scientists in their efforts to search for signs of ancient microbial life that may have been preserved in Martian rock.

Perseverance is exploring the top of a fan-shaped stack of sedimentary rock that is 250 meters high. and features curved layers that suggest flowing water. One question scientists want to answer is whether that water flowed in relatively shallow currents, closer than NASA’s Curiosity rover found evidence at Gale Crater, or in a more powerful river system.

Pieced together from hundreds of images captured by Perseverance’s Mastcam-Z instrument, two new mosaics suggest the latter, revealing important clues: coarse sediment grains and pebbles.

“Those indicate a high-energy river that is carrying a lot of debris. The more powerful the water flow, the more easily it can move larger pieces of material,” he said. it’s a statement Libby Ives, a postdoctoral researcher at NASA’s Jet Propulsion Laboratory, which operates the Perseverance rover.

With experience studying terrestrial rivers, Ives has spent the last six months analyzing images of the Red Planet’s surface. “It has been a pleasure to look at rocks on another planet and see processes that are so familiar,” Ives said.

Years ago, scientists noted a series of curved bands of layered rock within Jezero Crater that they called “the curvilinear unit.” They were able to see these layers from space, but were finally able to see them up close, thanks to Perseverance.

A location within the curvy unit, dubbed “Skrinkle Haven,” is captured in one of Mastcam-Z’s new tiles. Scientists are sure that the curved layers here were formed by powerfully flowing water.but detailed Mastcam-Z shots have left them debating which type: a river like the Mississippi, winding its way across the landscape, or a braided river like the Nebraska Platte, which forms small islands of sediment called shoals. .

When viewed from the ground, the curved layers appear arranged in rows that stretch across the landscape. They could be the remains of a river bank that changed over time, or the remains of sandbars that formed in the river.. The layers were probably much higher in the past. Scientists suspect that after these piles of sediment turned into rock, they were eroded by the wind over eons and carved to their current size.

“The wind has acted like a scalpel that has cut through the top of these reservoirs,” said Caltech’s Michael Lamb, a river specialist and contributor to Perseverance’s science team. “We see deposits like this on Earth, but they are never as exposed as they are here on Mars. The land is covered with vegetation that hides these layers.”

A second mosaic captured by Perseverance shows a separate location that is part of the curvaceous unit and approximately 450 meters from Skrinkle Haven. “Pinstand” is an isolated hill containing sedimentary layers that curve skyward, some up to 20 meters). Scientists believe that these upper layers may also have been formed by a mighty river, though they are exploring other explanations as well.

“These layers are abnormally high for rivers on Earth,” Ives said. “But at the same time, the most common way to create these types of landforms would be a river.”

The team continues to study the Mastcam-Z images for additional clues. They’re also looking below the surface, using the ground-penetrating radar instrument on Perseverance called RIMFAX (short for Radar Imager for Mars’ Subsurface Experiment). What they learn from both instruments will contribute to an ever-expanding body of knowledge about the ancient and watery past of Mars.

“What’s exciting here is that we’ve entered a new phase in the Jezero story. And it’s the first time we’ve seen environments like this on Mars,” said Perseverance deputy project scientist Katie Stack Morgan of JPL. “We’re thinking about rivers on a different scale than we had before.”