Avatar is a 2009 American epic science fiction film written and directed by James Cameron and starring Sam Worthington, Zoe Saldana, Sigourney Weaver, Michelle Rodriguez, and Stephen Lang. The film is set in 2154, when humans are mining a precious mineral called unobtanium on Pandora, a lush moon of a gas giant in the Alpha Centauri star system.The expansion of the mining colony threatens the continued existence of a local tribe of Na'vi—a sentient humanoid species indigenous to Pandora. The film's title refers to the genetically engineered Na'vi-human hybrid bodies used by a team of researchers to interact with the natives of Pandora.