Perseverance rocks point to several episodes of ancient water on Mars
Rocks examined by NASA’s Perseverance rover at the inner edge of Mars’ Jezero Crater show evidence of several ancient water episodes, according to a study described by NASA’s Jet Propulsion Laboratory on 21 September.
Scientists expected sedimentary rock in the crater’s Margin Unit, near the shoreline of an ancient lake, but found igneous rock altered by water. NASA says the rocks show signs of at least three interactions with water, involving groundwater, a possible lake-related episode and later heated underground fluids.
Perseverance used its SuperCam instrument to analyse more than 185 bedrock targets across the unit. The team found carbonate, silica and, at one location, minerals including calcium sulfate and fluorite. These help scientists reconstruct changing conditions in the crater.
The evidence relates to water and potential past habitability; it is not a discovery of life. The researchers can describe the sequence of water interactions but have not established the ages of those episodes. Perseverance continues to characterise Mars’ geology and collect samples for study.
