Ancient Aliens: Are oceans home to aliens?

This Ancient Aliens compilation explores whether extraterrestrial life could thrive in the deep ocean. Discoveries of new species and forms of life in the depths prompt questions about what else might survive in such an environment.

The series examines the controversial theory that extraterrestrials have visited Earth for millions of years. This segment turns to the oceans as a possible habitat for alien life; it does not establish that extraterrestrials have been found there.