A study published on Friday reveals that NASA’s rover Perseverance has collected data confirming the presence of ancient lake sediments in the Jerezo Crater on Mars. Ground-penetrating radar observations conducted by the robotic rover support earlier orbital imagery and data, leading scientists to hypothesize that some regions of Mars were once submerged in water, potentially providing a suitable environment for microbial life.
The research, published in Science Advances, focuses on a crater floor that flooded 3.7 billion years ago and transformed into an expansive delta resembling river deltas on Earth. The rover’s ground-penetrating radar, known as the Radar Imager for Mars’ Subsurface Experiment, or RIMFAX, scans the Red Planet to reveal hidden rock layers. On its journey along the delta between May and December 2022, the rover spotted tilted beds of sediments likely deposited by flowing water rather than by wind or sheet-like floods. The rover also captured images of a fan-shaped formation likely created by flowing water.
Scientists at the University of California Los Angeles and the University of Oslo analyzed the data obtained from the rover’s radar scans to build a timeline of events in the crater. Their analysis suggests that igneous rocks on the crater’s floor formed after an asteroid impact some 4 billion years ago, followed by a shallow lake that eventually became a delta. In later stages, the delta experienced flash floods that swept large boulders tens of miles upstream into the lake.
Perseverance began exploring the crater in February 2021 and has since collected and cached dozens of soil and rock samples for possible return to Earth. The rover has been carrying out a multi-year campaign in Jezero to identify and collect rocks that hold evidence of past life on Mars.
Researchers hope that the samples gathered by Perseverance, which are stored in special tubes and could be brought back to Earth for detailed examination with powerful lab equipment too big to transport to Mars, will contain fossilized remnants of microbial life. A team of experts is working to analyze these samples for signs of biological activity, which would be the most compelling evidence of life on Mars. For example, such evidence could be found in traces of organic molecules that form through geological and possibly biological processes.
The discovery of ancient lake sediments at the bottom of the Jezero crater boosts hopes that the search for life on Mars will be successful. It is the most significant discovery from the rover’s mission to date and is a crucial step toward understanding whether the planet ever hosted life. The next step will be to examine the samples from this crater and other sites on Mars to determine if life existed at any of these locations.