A rock containing many smaller round stones could indicate that there was once a large amount of liquid water on the Red Planet.

A mineral called siderite found abundantly in rock drilled by a NASA rover on the surface of Mars is providing fresh evidence of the planet's warmer and wetter ancient past when it boasted substantial bodies of water and potentially harbored life.

Since its touchdown in Jezero Crater in February 2021, NASA’s Perseverance rover has steadily explored Martian rocks. From ancient volcanic deposits to layers formed by vanished lakes and river deltas,