In the universe of Avatar, Pandora is depicted as being a planet that is, presumably, far away in outer space. But due to the rich story of Avatar and the many layers of Pandora that were explored, it was never explicitly addressed where Pandora was or how long it would take humans to get there. Although Earth is never seen in the film, it is referenced as a "dying world." Pandora, in turn, is a beautiful and lush world that is thriving thanks to a mineral called unobtainium which helps to power the giant tree that sits on top of it.

Avatar is set in 2154, which was revealed thanks to Jake's video recording before he becomes a Na'vi. Because it's set so far in the future, humans have improved their ability to space travel, which is fortunate, because Pandora is a reported 4.37 light years away, as the film depicts it...