The remains of ancient lake deposits found at the bottom of the Martian Crater Ezero open new prospects for finding traces of life in the samples collected by the NASA “Perseverance”.
The NASA rover “Perseverance” landed in the 45-kilometer wide Ezero crater on February 18, 2021, which is believed to have once housed a large lake and a river delta. The mission’s objective is to search for signs of ancient life by meticulously studying the crater and collecting numerous samples for potential future delivery to Earth.
A recent study conducted by researchers from the University of California at Los Angeles and Oslo University, using the Marshod instrument “Radar Imager for Mars’ Subsurface Experiment” (Rimfax), has unveiled new insights into the formation of precipitation layers at the bottom of the crater.
David Page, the first author of the study and deputy chief researcher of Rimfax, stated, “From the orbit we can see various deposits, but we cannot accurately determine whether they are in their original state, or if they resulted from a long geological process. To understand how they formed, we need to look under the surface.”
The Rimfax tool sends radio waves into the Martian surface as the rover traverses the Ezero crater, creating a profile of the underground structure up to a depth of 20 meters. The Rimfax data revealed that the precipitation layers were deposited by the water that once filled the crater, potentially indicating the past existence of microbial life. Therefore, the samples collected from the precipitation layers in this area could contain traces of ancient Martian life.
The study further identified two distinct periods of deposition, resulting in the formation of regular and horizontal layers of precipitation at the bottom of the crater, reminiscent of Earth’s sedimentary layers. These layers were formed due to fluctuations in the water level of the lake, ultimately leading to the creation of a large delta, which “Perseverance” extensively investigated from May to December 2022.
Radar measurements also highlighted the uneven bottom of the crater beneath the delta, suggesting previous erosion that occurred before the primary deposition of the precipitation layers. Subsequent drying of the lake caused further erosion, resulting in the geological features visible on Mars’ surface today.
“The changes that we see, preserved in the geological record, are a result of large-scale environmental changes on Mars,” stated David Page. “It is fascinating to witness numerous evidences of changes within such a small geographical area, allowing us to extrapolate our conclusions to the entire crater.”
The findings of this study were published on January 26 in the journal Science Advances