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

The aliens were next door, and somebody killed them. That’s the story plasma physicist John Brandenburg, PhD, tells about Mars. His theory suggests that a civilization built monuments on our ...

If ancient alien explorers ever traipsed through Earth's cosmic neighborhood, could it be possible they left behind some ...

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 ...

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 ...

Earthlings, brace yourselves: the galaxy may be emptier than your last Tinder date. According to a new study, any alien civilizations out there? Probably short-lived — and doomed to fail spectacularly ...

"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 ...