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.

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 ...

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

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.