Scientology founder L. Ron Hubbard based his religion on a belief in extra-terrestrials…

“At these higher levels … Scientologists learn Hubbard’s secret theory of human suffering,
which he traces to a galactic battle waged 75 million years ago by an evil tyrant named Xenu.”

From an L.A. Times article about Tom Cruise and Scientology:
https://www.latimes.com/business/la-fi-scientology18dec18,0,2963052.story?coll=la-home-headlines

Click on this image capture / screen shot to read the context of the above quote, in case the L.A. Times article is removed…