Theorists believe that thousands of years ago, extraterrestrials landed on Earth in the season 20 premiere of History Channel’s hit series “Ancient Aliens” set to air Thursday, January 15 at 9 p.m.

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: History Channel ...

The Pelasgians were the ancestors of the Greeks, remembered by ancient historians as the very foundation of Hellenic identity ...