New findings from NASA's Perseverance rover have revealed evidence of wave-formed beaches and rocks altered by subsurface water in a Martian crater that once held a vast lake—considerably expanding the timeline for potential habitability at this ancient site. In an international study led by Imperial College London, researchers uncovered that the so-called "Margin unit" in Mars's Jezero crater preserves evidence of extensive underground interactions between rock and water, as well as the first definitive traces of an ancient shoreline.