2001: A Space Odyssey is a 1968 science fiction novel by British writer Arthur C. Clarke. It was developed concurrently with Stanley Kubrick's film version and published after the release of the film. Clarke and Kubrick worked on the book together, but eventually only Clarke ended up as the official author. The story is based in part on various short stories by Clarke, including "The Sentinel" (written in 1948 for a BBC competition, but first published in 1951 under the title "Sentinel of Eternity"). By 1992, the novel had sold three million copies worldwide. An elaboration of Clarke and Kubrick's collaborative work on this project was made in the 1972 book The Lost Worlds of 2001. The first part of the novel, in which aliens influence the primitive ancestors of humans, is similar to the plot of Clarke's 1953 short story "Encounter in the Dawn". Plot summary A mysterious alien civilization uses a tool with the appearance of a large crystalline monolith to investigate worlds across the galaxy and, if possible, to encourage the development of intelligent life. The book shows one such monolith appearing in prehistoric Africa, three million years ago (in the movie, four mya), where it inspires a starving group of hominids to develop tools. The hominids use their tools to kill animals and eat meat, ending their starvation. They then use the tools to kill a leopard preying on them; the next day, the main ape character, Moon-Watcher, uses a club to kill the leader of a rival tribe. In AD 1999, Dr. Heywood Floyd travels to the Moon's Clavius Base, where a scientist explains that they have found an electromagnetic disturbance, designated Tycho Magnetic Anomaly One (or TMA-1), in the crater Tycho. Excavation has revealed a large black slab, precisely fashioned to a ratio of 1:4:9 (or 12:22:32) and therefore believed the work of intelligence. Visiting TMA-1, Floyd and others arrive just as sunlight falls upon it for the first time since it was uncovered; it emits a piercing radio transmission which the scientists determine is directed at one of the moons of Saturn, Japetus (Iapetus). A mission, Discovery One, is sent to Saturn. En route, Dr. David Bowman and Dr. Frank Poole are the only conscious humans aboard; their three colleagues are in suspended animation, to be awakened near Saturn. The HAL 9000, an artificially intelligent computer, addressed as "Hal", maintains the ship. While