From the Greys to the Nordics, these aliens appear frequently across abduction stories and science fiction tales.

Scientists are calling for a lunar quarantine facility where samples from Mars, the Moon, and beyond would be examined before being brought to Earth. They warn that even a tiny alien microorganism ...

NASA’s masterplan for upcoming lunar landings has a flaw that could prove fatal to the U.S. astronauts set to touch down on ...

Mono Lake, set in the eastern Sierra Nevada Mountains, is one of the most surreal places in the U.S. Aside from its ...

What movies have defined the sci-fi genre? Here, we're looking at the movies that established and sometimes reinvented the familiar hallmarks of sci-fi movies.

It was the late 1950s when Ruben Uriarte saw his first UFO — a silvery, oval-shaped object hovering by the Oakland foothills. “I thought maybe it was a blimp, because it was just hanging there. I ...

From insects to the moon, people have mistaken very Earthly phenomena for UFOs many times.

Astronomers discovered a moon-like object orbiting a brown dwarf that's orbiting a star. Say that three times fast.

Two scientists want NASA to build a quarantine lab for alien germs on the Moon, rather than on Earth. The pair, microbiologist and former Pentagon advisor Frederick Moxley and McGill University ...

A polarizing Harvard University astronomer known for splashy theories about alien visits has been tapped by the White House to lead a team of outside scientists to study the national security risks ...

As the peerless "Aliens" turns 40, here are 26 reasons it's still the greatest sci-fi action movie of all time.