Mare Crisium is a lunar mare, on Earth's moon, that was the first location of an alien artifact called a sentinel, that Arthur C. Clarke chose as a monolith for his 1951 short story, “The Sentinel”, but was later removed to the Tycho crater as TMA-1 for 2001: A Space Odyssey.
The Tycho crater is the setting in 2001: A Space Odyssey, of the location for where the first monolith was discovered by modern humans. Around 1999, American survey satellites discovered a strong magnetic field near the crater Tycho. It was first assumed to be a giant nickel-iron meteorite, but not even that could produce such an intense field. Excavation at the site in 1999, unveiled a three million year old black monolith buried 20 feet below the lunar surface. This monolith was officially dubbed Tycho Magnetic Anomaly One, or TMA-1.
Clavius Base is a US lunar research base on Earth's moon, featured in 2001: A Space Odyssey and its film adaption. The base is located in the Clavius crater, due south of Tycho. It was operated under the direction of the United States Astronautics Agency (USAA) from 1994 into 2001, until absorbed by the NCA. They oversaw the excavation project of the TMA-1, near the Tycho crater, and sent Heywood Floyd to investigate.Tchalinko Base is a Soviet operated base mentioned only in the 2001 film. However, a related reference in the novel suggests that it might be affiliated with a Russian observatory located on the far side of the Moon. In 1999, Elena and a group of Russian scientists spend three months at Tchalinko Base, calibrating a new antenna. They later meet with Heywood Floyd, on their return to Station V, to see if they can acquire some information about the “epidemic” that was heard about at Clavius.
The Serenitatis Base is a lunar base located in Mare Serenitatis, first mentioned in Arthur C. Clarke’s 1951 short story, The Sentinel. Two heavy freighters fly in supplies and equipment to Mare Crisium, from the main base at Serenitatis. An ancient pyramid, twice the size of a man, is discovered at Crisium by the narrator. This was the inspiration for the TMA-1 in Kubrick and Clarke’s joint 2001 project.