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 ...

Suppose an alien civilization discovers Earth and decides to investigate. Before it chooses a landing site or considers how ...

Claims that aliens are already here are everywhere, but proving them is another matter. The strongest cases become more ...

The mathematical certainty that 'they' definitely exist in the universeWhen looking up at the night sky, everyone has surely ...

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 ...

Is anybody out there? Probably. Most stars have planets; we've discovered more than 6,000 exoplanets thus far, and the most basic statistics point toward the existence of countless potentially ...

With billions of potentially habitable worlds scattered across the universe, alien civilizations should be out there — yet ...

For decades, science fiction writers have tried their best to prepare us for eventual contact with aliens. Their efforts are dominated by several recurrent tropes. There's the invasion by a warlike ...

In 1950, famed astrophysicist Enrico Fermi posed a profound question during a casual lunch with colleagues: Where is everybody? In other words, if there’s an extremely high probability that advanced ...

For decades, SETI researchers have focused on finding narrow-band radio signals that might stand out from the natural universe. But what if an advanced civilization that wanted to communicate would ...