Rover Perseverance finds ancient lake deposits on Mars. Understanding discovery | technology

Deposits from an ancient lake discovered at the base of Jezero Crater Rover Perseverance It raises hope that traces of life can be found in soil and rock samples collected on Mars. This is according to new research published on Friday the 26th in the journal Science Advances, led by a team from the University of California, Los Angeles (UCLA) and the University of Oslo in Norway.

“At some point, the crater filled with water, depositing layers of sediment at the bottom of the crater. The lake then contracted, and the sediment carried by the river that fed it formed a huge delta. As the lake dissipated over time, the sediments that appeared in the crater eroded, forming the geological features.” visible on the surface today,” says UCLA.

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The US Space Agency (NASA) robot, which arrived on the Red Planet in February 2021, collected new data using radar.

“Ground-penetrating radar aboard NASA's Mars Perseverance Rover has confirmed that Jezero Crater, formed by an ancient meteorite impact north of the Martian equator, was once home to a vast lake and river delta,” according to UCLA.

The device also indicates that periods of deposition and erosion occurred over eons of environmental change, confirming the accuracy of inferences about the geological history of Jezero Crater based on images of Mars obtained from space.

“In orbit, we can see many different deposits, but we can't say for sure whether what we see is their original state or the completion of a long geological history. To figure out how these things formed, we need to look below the surface.” said David Page, one of the paper's authors and a professor of Earth, planetary and space sciences at UCLA.

NASA's rover, about the size of a car and carrying seven scientific instruments, has been exploring the 30-mile-wide crater, studying its geology and atmosphere and collecting samples from the red planet for nearly three years. “Soil and rock samples from the probe will be returned to Earth by a future expedition and studied for evidence of past life,” the university said.

Between May and December 2022, NASA's robot headed from the bottom of the crater to the delta, a vast expanse of three-billion-year-old sediment that, in orbit, resembles river deltas on Earth.

“As the rover headed toward the delta, the Subsurface Mars Experiment Radar Imager, known as RIMFAX, fired radar waves downward at ten-centimeter intervals and measured reflected pulses from depths of about twenty meters below the surface.” Look at the base of the sediment to reveal the upper surface of the buried pit floor,” adds UCLA.

According to the publication, the resulting image shows underground rock layers that could be interpreted as road cuts. However, artifact representation revealed two distinct periods of sediment deposition that fell between two periods of erosion.

“The UCLA and University of Oslo point out that the floor of the crater below the delta is not uniformly flat, suggesting a period of erosion occurred before the lake sediments were deposited. Radar images show that the sediments are regular and horizontal – just like sediments deposited in 'lakes on Earth.' The presence of lake sediments has been suspected in previous studies, but has been confirmed by this research,” UCLA said.

According to the foundation, a second period of sedimentation occurred when fluctuations in lake level allowed the river to deposit a wide delta that once extended into the lake, but has now been eroded near the river mouth.

“It's great that we can see so much evidence of change in such a small geographic area, allowing us to expand our results to include the size of the entire crater,” Paige said.