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

From Viking to Perseverance, scientists have spent decades chasing chemical hints that could point to life beyond Earth.

I/ATLAS has passed its closest point to Earth, meaning we will soon lose sight of it for good. Some scientists want to send a spacecraft to chase down the alien comet — or the next interstellar object ...