Martian settlers: fill your water bottles (science: video).

This movie, based on images taken by ESA’s Mars Express, showcases the water-ice-filled 82 km-wide Korolev crater on Mars, where the first Martian settlers will be setting up their water mines to survive without shipping H2O from Earth.

Located in the northern lowlands of the Red Planet, this impact crater is filled with water ice all year round. The crater’s floor lies two kilometers below its rim, enclosing a 1.8 km thick domed deposit that represents a large reservoir of non-polar ice on Mars.

Water ice is permanently stable within Korolev crater because the deepest part of this depression acts as a natural cold trap. The air above the ice cools and is thus heavier compared to the surrounding air: since air is a poor conductor of heat, the water ice mound is effectively shielded from heating and sublimation.