Experts believe ancient alien civilizations have been living on mars. See more in this clip from Season 1, Episode 7, ...

Could ancient humans really have built the pyramids without extraterrestrial help? Or do such questions reveal more about modern anxieties than the past itself? The idea that aliens assisted the ...

Aliens did not visit Earth in the distant past. They didn't build the pyramids or rule ancient Greece from Mount Olympus or teach Mesoamericans how to plant corn. How do I know? Because they didn't do ...

What if the pyramids of ancient Egypt were not just tombs?The massive structures built in the desert were actually spaceships from an extraterrestrial civilization, housing cities that have continued ...

Add Yahoo as a preferred source to see more of our stories on Google. Distance, light speed, biology, and time may explain why alien civilizations never meet. (CREDIT: Wikimedia / CC BY-SA 4.0) "There ...

A new study proposes searching the moon for remnants of ancient extraterrestrial technology. Researchers suggest the moon's surface could preserve microscopic "technosignatures" left by alien ...

Erich von Däniken proposed that monumental structures such as the pyramids could have been built with help from aliens. Stefan Baumann Could ancient humans really have built the pyramids without ...

"There is a silence in the night sky that has bothered me for as long as I can remember." That line, attributed to Richard Feynman, lands because it gets at a simple, stubborn feeling. The sky looks ...