Geological Chronicle
Prominently situated in the southern hemisphere on the far side of the Moon, Tsiolkovskiy spans 184.39 km across and protrudes into neighbouring Fermi, an older crater of comparable size without a lava-flooded floor. The crater possesses high, terraced inner walls enclosing a well-formed central peak that rises over 3200 m above the floor. In contrast to typical farside terrain, a dark-hued mare characteristic of near-side lunar maria covers the floor, concentrating more heavily to the east and south while a darker bay reaches the west-northwest wall.
Spectroscopy of the formation has identified the infrared spectrum of pure crystalline plagioclase. Tsiolkovskiy also has an unusually high rockfall density for its diameter, though this does not apply to its northwest rim. Far to the northeast in Mendeleev crater, the crater chain Catena Mendeleev points directly at Tsiolkovskiy, leading researchers to believe that its small craters are secondaries from the Tsiolkovskiy impact.
Discovered on photographs returned by the Russian spacecraft Luna 3, the feature was named for Konstantin Tsiolkovsky and subsequently imaged by several American Lunar Orbiters and Apollo astronauts. Geologist Harrison Schmitt and other scientists strongly advocated Tsiolkovskiy as the landing site for Apollo 17, using small communications satellites deployed from the Command/Service Module to maintain contact from the lunar far side. NASA vetoed the idea as too risky, and Apollo 17 landed instead in the Taurus-Littrow valley on December 11, 1972.