Dusty Water Ice in Mars' Dao Vallis

The white material seen within this gully is believed to be dusty water ice in a Martian region called Dao Vallis, captured by NASA's Mars Reconnaissance Orbiter (MRO). Scientists believe dust particles within this ice act similarly to dust that falls on to glaciers on Earth, warming up in sunlight and causing subsurface pockets of meltwater to form. On Earth, the dust that forms these pockets are called cryoconite, and the pockets are called cryoconite holes.