One of Mars' longest ancient river valleys, feeding a crater lake.
Ma'adim Vallis is one of the largest valley systems on Mars, running roughly 700 km and reaching up to 20 km wide and 2 km deep. It carved northward through the highlands and emptied into Gusev crater, once explored by the Spirit rover.
Claim your plot here →Ma'adim Vallis cuts northward across the ancient cratered highlands, a deep, branching canyon up to 20 km wide. Its size and tributaries point to sustained or repeated water flow, whether from rainfall, meltwater, or the catastrophic draining of large highland lakes to the south. Where it ends, it spills into Gusev crater.
Gusev was long suspected to have held a lake fed by the valley, which is why NASA sent the Spirit rover there in 2004. Although Spirit found more volcanic rock than lake sediment on the crater floor, Ma'adim Vallis remains one of the clearest signs that flowing water once shaped the Martian surface on a grand scale.
Comparable in length to some of Earth's great river valleys, but carved into a frozen, near-airless world.
Far smaller than the great rift, but a genuine water-cut river valley rather than a tectonic canyon.