NASA's Perseverance Mars rover finds groundwater

NASA’s Perseverance rover has uncovered a surprisingly complicated history of water in Jezero Crater. Scientists expected the crater’s Margin Unit to contain lake sediments, but instead found ancient igneous rocks that were altered by water on at least three separate occasions. NASA’s Perseverance Mars rover finds groundwater, lakes, and hot fluids in one place.

When NASA’s Perseverance rover arrived at the inner rim of Mars’ Jezero Crater in September 2023, researchers expected to encounter sedimentary rocks along what was once the shoreline of a Martian lake. Such rocks form as layers of material accumulate over long periods of time. On Earth, sedimentary rocks made from clay and silt can be especially valuable because they are capable of preserving evidence of ancient microbial life.

Scientists were also interested in the area because Mars orbiters had detected strong signatures of carbonate minerals there. On Earth, carbonates commonly develop in shallow lakes and oceans, including environments that can support life. Instead of the expected sedimentary deposits, Perseverance encountered igneous rock.