Curiosity…5 years ago
Perseverance is not even the first rover on Mars to find evidence of organics. Curiosity detected 3.5-billion-year-old organics in Mars’ Gale Crater back in 2018. Two papers on the findings revealed that Curiosity detected carbon-containing organic matter (note: this does not mean organic matter in the sense of decomposing remains of a living thing, just organics on a molecular level), and that methane levels around the rover varied by season.
Curiosity is also regularly imaging signs of ancient water in Gale Crater. The above shot was taken in June 2022, and showcases layers of flaky rocks that may have sat at the bottom of an ancient stream or pond.
