Planets that once lived only in pulp novels and movie concept art are now turning up in real data. Astronomers are not just ...

Humans should look to planetary alignments outside of the solar system when searching for signatures of extraterrestrial communications, scientists say. The nascent search for radio transmissions from ...

A team of astronomers claims to have sniffed out a “biosignature” in the atmosphere of a distant planet called K2-18b. But not everyone agrees that it signals life. An illustration shows what ...

The Search for Extraterrestrial Intelligence (SETI) focuses on finding technosignatures—potential signs of alien technology. If we look carefully, we might have a chance at detecting their ...