What is the diameter of the lunar crater Mendeleev?

The lunar crater Mendeleev is 313 kilometres in diameter.

Mendeleev is a large impact crater—or, more precisely, a broad walled plain—on the far side of the Moon. Because it lies on the hemisphere turned away from Earth, it cannot normally be viewed directly from our planet. Its southern rim crosses the lunar equator, and the feature contains a relatively level interior marked by several smaller craters.

The crater is named for Dmitri Mendeleev, the Russian chemist associated with the periodic system of the elements. The International Astronomical Union formally approved the name in 1961. Before its official naming, the feature was known as Basin IX, and the name Mendeleev became established in lunar mapping during the following decade.

Several named craters occupy or touch its interior and rim, including Schuster, Hartmann, Bergman, Fischer, Richards, and Moissan. The interior also contains Catena Mendeleev, a chain of small craters. Mendeleev is considered a basin of Nectarian age, while parts of its floor contain deposits assigned to the Imbrian-age Cayley Formation. Its 313-kilometre diameter makes it vastly larger than ordinary small lunar craters.