Perseverance findings reveal multiple ancient water episodes at Jezero Crater

Sep 21, 6:55 PM UTC

Margin Unit rocks record at least three distinct interactions with water

Perseverance observations show that Jezero Crater’s Margin Unit interacted with water on at least three separate occasions, according to a newly published analysis. The sequence began when carbon-dioxide-rich groundwater altered olivine and formed carbonate-filled fractures. A second episode may have involved Jezero’s ancient lake, while later heated groundwater produced mineral veins containing calcium sulfate and fluorite. The results revise the earlier hypothesis that the unit’s carbonates formed solely through lake activity. Researchers can determine the sequence but not the ages of these episodes. Although carbonate and silica can preserve traces of past microbes on Earth, the findings do not establish evidence of ancient Martian life. This briefing covers 2026-09-20T06:53:38.409Z through 2026-09-21T18:53:38.409Z. The timestamp is NASA publication metadata, not the time of the ancient geological events.

NASA: NASA Discovery Reveals Complex Water Systems on Early Mars