Add Yahoo as a preferred source to see more of our stories on Google. For decades, humanity has scoured the cosmos for any signs that we aren't alone in the universe. But now, researchers at the SETI ...

Stellar plasma can smear alien radio signals before they escape their star system, making them harder for astronomers to detect.

The third known visitor from another star system, Comet 3I/ATLAS, has been racing through the Solar System with just enough weirdness to ignite a familiar debate: is it natural or could it be ...