Evidence of ancient lake sediments at the base of Mars’ Jezero crater offers new hope for finding traces of life in samples collected by NASA’s Perseverance rover. Perseverance touched down on 18 February 2021 inside the crater, which is believed to have once hosted a large lake and river delta. The rover has been scouring the crater in search of signs of past life and collecting and caching dozens of samples along the way for a possible future return to Earth. Using the rover’s Radar Imager for Mars’ Subsurface Experiment (RIMFAX), researchers from the University of California, Los Angeles (UCLA), and the University of Oslo revealed new clues about how sediment layers formed over time on the crater floor. “From orbit we can see a bunch of different deposits, but we can’t tell for sure if what we’re seeing is their original state, or if we’re seeing the conclusion of a long geological story,” David Paige, RIMFAX’s deputy principal investigator, said. “To tell how these things formed, we need to see below the surface.”
As Perseverance travels across the surface of Mars, the RIMFAX instrument sends radar waves down at ten-centimetre (four-inch) intervals and measures pulses reflected from depths of about 20 metres (65.6 feet) below the surface to create a subsurface profile of the crater floor. The RIMFAX data showed evidence of sediment deposited by water that once filled the crater. It’s possib
