The Korolev crater, or the icy crater is a crater measuring 51 miles across and is located in the northern lowlands of Mars, just south of the pole. It was named after the renowned engineer Sergei Korolev, known as the father of Soviet space technology, who worked on the Sputnik programme.
At a depth of 1.2 miles, scientists think the chasm traps a layer of cold air that ensures its icy core remains in place all year round. As air moves over the surface of the crater it sinks and creates a low temperature zone that preserves the ice by shielding it from the surrounding atmosphere.
The presence of liquid water on Mars has been the subject of much debate for years, and its discovery could hold the key to finding alien life there. However, scientists have long known that much of the red planet’s polar regions are adorned with a layer of ice. Scientists noted the Korolev site was a particularly well-preserved example of a frozen Martian crater.
In volume, it contains around 2,200 cubic kilometres (528 cubic miles) of ice (although an unknown proportion of it is probably Mars dust which would have to be filtered out).
The same dynamic is at play in the much smaller 36-kilometre (22.4-mile) Louth crater, also in the northern polar region of Mars.
If there is a lava tube nearby you have the makings of an underground colony without importing much oxygen or water. That makes it a big deal.