A mysterious metal shard, once thought to be a piece of a UFO that crashed in 1947, has sparked years of wild speculation.

From mudstones on Mars to strange gases in exoplanet atmospheres, tentative evidence for extraterrestrial life is starting to ...

An “alien plant” fossil discovered 55 years ago just outside of an abandoned town in Utah has no relation to any currently ...

Astronomers thought they had seen the "first hints of life on an alien world" this year, but they disappeared under closer ...

Aliens might be transmitting communications signals to each other across exoplanets, some astronomers think. Since these signals are likely sent as narrowband radio waves, we may now have a way to ...