Perseverance rover finds signs of ancient lake on Mars: a step closer to unveiling past life?

Recent findings about the Jezero Crater, researched by the Perseverance rover, lead to the conclusion that it was once filled with water - report scientists from the University of California, Los Angeles (UCLA), in the journal "Science Advances".

Researchers believe that in the past, a lake existed in the Jezero Crater that eventually began to shrink. A river that fed this lake brought sediments with it, gradually forming a massive delta. The lake bed was eroded over time, leading to the formation of structures presently visible on the surface.

Planetary scientists explain that the sedimentation and subsequent erosion processes lasted for aeons, spanning at least 500 million years.

Data collected by the Perseverance rover supports previous hypotheses based on photos of the region taken from orbit. While in orbit, we can observe various sediments but cannot be certain if they are in their original state or are the result of long-term geological processes. To understand how these formations were created, it's necessary to examine below the surface - says Prof. David Paige of UCLA.

Since 2021, the Perseverance rover has been studying a crater over 31 miles in diameter. Between May and December 2022, it moved from the bottom of the crater to the mentioned river delta, formed from sediments up to 3 billion years old. Thanks to an onboard radar device on the rover, scientists could examine as far as 66 feet below the surface.

An analysis of the data detected two periods of sediment deposition, interspersed with two periods of erosion. One of the sediment layers formed when fluctuations in the lake's water level allowed the river to create a large delta. At some point, this delta extended far into the lake area and later eroded to the area near the river's mouth.

The sediments are arranged in even, horizontal layers - patterns akin to structures seen on Earth. It was also discovered that the surface of the crater, hidden under the deposits, is uneven, hinting at erosion processes that occurred before the deposition of the lake's sediments.

"The changes we observe in the rock record result from significant fluctuations in the Martian environment. It's remarkable that we can observe so many indicators of these changes in such a compact geographical area. This allows us to generalize our results to the entire crater," notes Prof. Paige.

In the future, scientists plan further analyses of samples collected by the Perseverance rover, intended to be brought back to Earth during future missions. There is a chance that these samples may contain evidence of ancient life on Mars.

Source: PAP