Curiosity finds clear clues to the existence of water on ancient Mars

Curiosity found the trace of waves in ancient lakes on Mars .


The rover has found these wavy rock textures preserved in what is known as the “Marker Band,” a thin layer of dark rock that juts out from the rest of Mount Sharp

Rippled textures in rocks studied by NASA ‘s Curiosity rover suggest the past existence of lakes in a region of ancient Mars that scientists expected drier.

Curiosity , which landed on Mars in 2012, is currently exploring a unique feature known as the “Marker Band” in the foothills of Mount Sharp

Strong evidence of lakes

The rocks in this area show the clearest evidence of waves the mission has ever seen: rippled textures that formed billions of years ago, when waves on the surface of a shallow lake stirred up bottom sediments. of the lake

Higher up the mountain, Curiosity can see more evidence of ancient water: Wet landslides caused rocks and other debris to slide down a valley. Curiosity was able to see these debris from a distance, but the rover team hopes to be able to take a closer look at it in 2023.

“This is the best evidence of water and waves we’ve seen on the entire mission,” Ashwin Vasavada, Curiosity project scientist at NASA’s Jet Propulsion Laboratory in southern California, said in a statement. “We went up through thousands of meters of lake deposits and never saw evidence like this – and now we found it in a place we expected to be dry.”

Since 2014, the rover has been ascending the foothills of Mount Sharp, a 5km-high mountain that was once crisscrossed by lakes and streams that would have provided a rich environment for microbial life, if it ever formed on it. the Red Planet.

Mount Sharp is made up of layers, the oldest at the bottom and the youngest at the top. As the rover ascends, it moves along a Martian timeline, allowing scientists to study how Mars evolved from a more Earth-like planet in its ancient past, with a warmer climate and abundant water, to the frozen desert that it is today.

After ascending nearly 800 meters above the mountain’s base, Curiosity found these undulating rock textures preserved in what is known as the “Marker Band,” a thin layer of dark rock that juts out from the rest of Mount Sharp. This layer of rock is so hard that Curiosity has been unable to drill a sample of it despite several attempts.

They will look for more footprints

Scientists will look for softer rocks over the next week. But even if they never get a taste of this unusual strip of rock, there are other places they’re eager to explore.

Far ahead of the Marker Band, scientists can see another clue to the ancient water history of Mars in a valley called Gediz Vallis. The wind sculpted the valley, but a small river is believed to have eroded a channel that begins further up Mount Sharp. Scientists suspect that wet landslides occurred here as well, sending rocks and debris the size of a car into the valley floor.

Because the resulting rubble pile sits on top of all other layers in the valley, it is clearly one of the youngest features on Mount Sharp. Curiosity was able to see this debris on Gediz Vallis Ridge twice last year, but was only able to inspect it from a distance. The rover team hopes to have another chance to see it later this year.

Another clue that has fascinated the team is the unusual texture of the rocks, likely caused by some kind of regular cycle in weather or climate, such as dust storms. Not far from the undulating textures are rocks made up of layers that are regular in their spacing and thickness. This type of rhythmic pattern in the rock layers of the Earth is usually due to atmospheric phenomena that occur at periodic intervals. It is possible that the rhythmic patterns of these Martian rocks are due to similar events, indicating changes in the Red Planet’s ancient climate.

“Wave undulations, debris flows, and rhythmic layering tell us that the wet-to-dry transition history on Mars was not a straightforward one,” explains Vasavada. “The ancient climate of Mars was very complex, like that of Earth.”

(With information from Europa Press)