NASA's Perseverance rover on Mars has discovered unusual "float" rocks on the rim of Jezero Crater while searching for signs of ancient microbial life. Scientists are investigating their origin.

NASA's Curiosity rover has found iron-rich carbonates on Mars — a major clue that the Red Planet used to be habitable.

The Curiosity rover recently uncovered large deposits of carbon within sulfate-rich layers of Mount Sharp in Mars’ impact basin, Gale Crater. In a paper published this month in the journal Science, data from three of Curiosity’s drill sites revealed an abundance of siderite—an iron carbonate mineral that had been a missing piece in the puzzle of Mars’ wet,