Perseverance’s radar revealed ancient subsurface river delta on Mars

NASA's Perseverance rover detected a previously unknown ancient river delta buried tens of meters below Jezero Crater's surface using ground-penetrating radar called RIMFAX. The discovery, interpreted by UCLA astrobiologist Emily L. Cardarelli and her team, reveals what is likely an older delta than the well-studied Western Delta visible above ground. The subsurface delta represents a promising location to search for biosignatures, as microbial life could have potentially developed in those ancient aquatic environments. RIMFAX continuously fires radar waves into the ground and constructs two-dimensional vertical slices of the Martian crust by measuring how radio signals bounce back from different rock, ice, and sediment layers.