Pandora is inhabited by the Na'vi. They are a blue-skinned species of humanoids with feline characteristics. Physically, the Na'vi are much stronger and taller than humans. They live in harmony with Nature and worship a mother goddess called Eywa. The human scientists on Pandora want to learn about the Na'vi's culture. To do this, they have created "avatars". Avatars are Na'vi bodies modified with human DNA. They are controlled mentally by human operators. These avatars are used to interact with the Na'vi people, to try to create peace. Jake Sully (played by Sam Worthington) is a paraplegic marine . His brother was a scientist trained to be an avatar operator. After his brother dies, Jake replaces him to control his avatar. Jake receives the mission to form relations with the Na'vi. His goal is to get the Na'vi to move away from Hometree so the humans can mine for unobtanium there. To do this, he was to become friends with the Na'vi so he could learn what it would take to get them to move. Many people, like Grace (played by Sigourney Weaver), an avatar specialist, did not think Jake had enough experience and intelligence to be useful. On a mission in avatar form, he gets lost in the jungle.