Avatar is a science fiction film written and directed by James Cameron, starring Sam Worthington, Zoë Saldaña, Stephen Lang, Michelle Rodriguez, and Sigourney Weaver. It was made by Lightstorm Entertainment and released by 20th Century Fox on December 18, 2009. The film is set in the year 2154 on Pandora, a fictional Earth-like moon in a distant planetary system. Humans are engaged in mining Pandora's reserves of a precious mineral known as unobtanium, while the Na'vi — the sapient and sentient race of humanoids indigenous to the moon — resist the colonists' expansion, which threatens the continued existence of the Na'vi and the Pandoran ecosystem. The film's title refers to the remotely controlled, genetically engineered human-Na'vi bodies used by the film's human characters to interact with the indigenous population.