The lead author of a new study pointing to more proof of water on Mars says it brings scientists a step closer to determining whether the planet was ever capable of supporting life.

To study Mars’s chemical and mineral makeup, the Curiosity rover drills one to 1.5 inches down into the subsurface, then drops the powdered rock samples into an instrument in its belly called CheMin. The instrument, developed at NASA’s Ames Research Center in California’s Silicon Valley, uses X-ray diffraction to analyze rocks and soil.