While there’s no single accepted definition of life, scientists agree on some of the key clues. Gases like oxygen, carbon dioxide and methane in a planet’s atmosphere can serve as possible indicators ...

Alien planets are far away but extreme lasers on Earth are giving scientists a way to investigate what they're like.

New SETI research suggests space weather like solar winds could be interfering with alien radio signals, making them harder to detect.

Small, rocky planets can coalesce around a wide variety of stars, suggesting that Earth-like alien worlds may have formed early and often throughout our Milky Way galaxy's history, a new study reveals ...

If advanced aliens lived on a planet within a few hundred to a thousand light years away from Earth, then vast numbers of their signals must already have crossed Earth without being noticed, a new ...

Despite the universe's vastness, containing billions of stars and galaxies, humanity has yet to encounter alien life.

"Milky Way season," when our galaxy's bright center is most visible, is now beginning in the Northern Hemisphere. The best time to see the Milky Way in the US is generally from March to September.

The question of whether aliens exist is not a new one. In science fiction films and books, people have wondered if we’re the only life in this universe and what that can imply for universes beyond ...