In 2015, geologist Colin Dundas of the U.S. Geological Survey in Flagstaff, Ariz., and colleagues discovered what looked like
streaks of salty water that appeared and disappeared in Gale Crater, where Curiosity is roving.
Those are narrow, dark - toned
streaks that go down steep Martian slopes, which could be
water tracks
of salty brines, and potentially home to Martian life.