Giorgio A. Tsoukalos talks about the Alien Astronaut Theory & the new episodes of "Ancient Aliens" on The History Channel.
When you buy through links on our articles, Future and its syndication partners may earn a commission. While we wait for Alien: Earth's next chapter to arrive, there's plenty for you to catch up on.
Some results have been hidden because they may be inaccessible to you
Show inaccessible results
Feedback