Mars rover discovers clear evidence of ancient water

NASA's Perseverance rover shows there once was water on Mars. Researchers now hope the rover will also find evidence of past life.

Los Angeles – When it came to choosing a landing site for the Mars rover Perseverance, NASA chose Jezero Crater. The background was the suspicion that it might be a former lake. Since landing in February 2021, the rover has already found several fairly clear indicators at its landing site The water may have already flowed once. Now the rover has discovered clear evidence of ancient water in Jezero Crater on Mars from a different perspective.

NASA's Perseverance rover looks beneath the surface of Mars

To do this, Perseverance used its RIMFAX ground-penetrating radar to look deep beneath the surface of Jezero Crater. The vehicle sent radar waves to the ground every ten centimetres, penetrating to a depth of 20 metres. Through the data that the rover was able to collect on Mars, researchers can take a closer look at how the soil is formed in the crater. “Some geologists say that radar's ability to see beneath the surface is a bit of a scam,” smiles David Page, vice president of RIMFAX Investigations.

“From orbit we can see a range of different deposits, but we cannot say with certainty whether what we see is their original state or whether we are witnessing the end of a long geological history,” Page points out in one article. notice. “To know how these things formed, we have to look beneath the surface.”

NASA's Perseverance rover looks beneath the surface of Mars

And that's exactly what Perseverance did on behalf of the research team on Earth – and sent exciting data back to Earth: The images show clear evidence of two different periods of sediment deposition, which lie between two periods of erosion. The sediments are regular and horizontal, just like sediments deposited in lakes on Earth. This means that Perseverance can confirm the presence of lake sediments in Jezero Crater on Mars for the first time.

“Large-scale changes in the Martian environment”

“The changes we see in the rocky record are due to large-scale changes in the Martian environment,” Page asserts. The researcher is pleased: “It is 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 entire crater.”

The study was conducted by the Paige research team In the specialized magazine Advancement of science published. Overall, the work shows that the Martian crater was once filled with water, which deposited layers of sediment on the crater floor. Over time, the lake shrank. The river feeding the lake carried sediment – and a huge river delta was formed. Over time, the water in the lake and river disappeared, the sediments eroded, and geological features appeared that can still be seen on Mars today.