Thomas Mulligan examines the scientific challenge of defining and searching for non-Earth-like alien life forms that may not ...

Tiny life forms adrift in alien skies might one day expose themselves through the faintest play of light. A new study suggests that airborne microbes could leave detectable spectral fingerprints in ...

We have no idea what kind of life may exist on other planets, so it’s hard to know what to look for. Proxima Kósmos imagines ...

Neil deGrasse Tyson is an astrophysicist who is the director of the Hayden Planetarium at the American Museum of Natural ...