Mare Frigoris

Mare Frigoris

Mare Frigoris is the dark grey material in the lower portion of this photo
Coordinates	56°00′N 1°24′E / 56.0°N 1.4°E / 56.0; 1.4Coordinates: 56°00′N 1°24′E / 56.0°N 1.4°E / 56.0; 1.4
Diameter	1,446 km (899 mi)
Eponym	Sea of Cold

Mare Frigoris (the "Sea of Cold") is a lunar mare in the far north of the Moon. It is located in the outer rings of the Procellarum basin, just north of Mare Imbrium, and stretches east to north of Mare Serenitatis. It is just north of the dark crater Plato.

The basin material surrounding the mare is of the Lower Imbrian epoch, while the eastern mare material is of the Upper Imbrian epoch, and the western mare material is of the Eratosthenian epoch.

Like most of the other maria on the Moon, Mare Frigoris was named by Giovanni Riccioli, whose 1651 nomenclature system has become standardized. Previously, William Gilbert had included it among the Insula Borealis ("Northern Island") in his map of c.1600, and Michael Van Langren had labelled it the Mare Astronomicum ("Sea of Astronomy") in his 1645 map.Pierre Gassendi called it the Boreum Mare ('Northern Sea').

This area of the Moon featured prominently in 'Behemoth', the second episode of the 1973 BBC science fiction mini-series Moonbase 3.