“The discovery of abundant siderite in Gale Crater represents both a surprising and important breakthrough in our understanding of the geologic and atmospheric evolution of Mars,” Benjamin Tutolo, associate professor at the University of Calgary, Canada, and lead author of the paper, said in a statement.

The image marks what may be the first time one of the agency’s Mars orbiters has captured the rover driving. NASA’s Curiosity Mars rover has never been camera shy, having been seen in selfies and images taken from space.

Scientists using NASA’s Curiosity rover have discovered siderite—an iron carbonate—in the sulfate-rich rocks of Gale Crater, solving a long-standing mystery about Mars’ missing carbonates. This find p