Remnants of ancient lake sediments discovered at the floor of Mars’ Jezero Crater offer a new perspective in the search for signs of life in samples collected by NASA’s Perseverance rover. Perseverance landed in Jezero Crater on February 18, 2021. This 45-kilometre-wide crater on Mars is thought to have once been home to a large lake and river delta. The rover will explore the crater for signs of ancient life and collect and store dozens of samples for possible future delivery to Earth. Researchers from UCLA and the University of Oslo are using the rover’s Radar Imager for Mars Surface Experiment (RIMFAX) instrument to learn new information about how layers of sediment formed on the crater floor over time. details were revealed. David Page, lead author of the study and deputy principal investigator at RIMFAX, said: “We can see a variety of deposits from orbit, but we have no idea whether they are in their original state or the result of long geological processes.” We cannot say with certainty whether this is the result of To understand how they came about, we need to look below the surface. ”
As Perseverance moves across the surface of Mars, the RIMFAX instrument will transmit radio waves to a depth of 20 meters, creating subsurface contours of craters. RIMFAX data showed that the sediment was deposited by water that once filled the crater. Microbial life may have existed within the crater at this time, and if such life existed on Mars, sediment samples from the area would contain traces of microbial life. Become. Two distinct periods of deposition have been identified, producing regular, horizontal-appearing layers of sediment at the crater floor, similar to Earth’s strata. Perseverance surveyed the delta between May and December 2022, where a large delta formed due to fluctuations in the lake’s water level. Radar measurements also show that there is an uneven crater floor beneath the delta, probably due to erosion that occurred before initial deposition. Then, as the lake dried up, the layers of sediment within the crater eroded away, forming the geological features seen on Mars’ surface today. “The changes we see in the geological record are driven by large-scale changes in the Martian environment,” Page said. “It’s interesting to see so much evidence of change in such a small geographic area, and allows us to extrapolate our findings to the entire crater.” The findings were published in the journal Science Advances on January 26th.
source: https://www.science.org/doi/10.1126/sciadv.adi8339