Assuming intelligent aliens know how to harvest energy from stars, would humanity be able to spot these high-level structures?

Our search for extraterrestrial life has turned up empty, perhaps because technologically advanced civilizations are doomed ...

Are aliens real? The question has animated conspiracy theories for decades and enthralled at least one former president of the United States. In a recent interview, Barack Obama became the first ...

A recent theory proposed by a NASA scientist suggests that extraterrestrial civilizations may not possess the wildly advanced technology that many UFO enthusiasts expect. This perspective, which ...

Add Yahoo as a preferred source to see more of our stories on Google. Sometimes it seems like we got to the galactic party late and everyone has already gone home. Our species only figured out how to ...

There's a definite buzz going around this month about aliens from other worlds, or hadn't you noticed? Former US President ...

Bring up aliens and a lot of people will scoff. But not everyone is laughing. Around the turn of the century, 3.8 million people banded together in a real-time search for aliens -- with screensavers.

A provocative theory circulating among artificial intelligence researchers suggests that once machines achieve human-level intelligence and beyond, they might create something entirely unexpected: a ...

Researchers at SETI (the Search for Extraterrestrial Intelligence) might be looking for the wrong thing, says one of SETI's astronomers in The Guardian. They're looking for aliens that are like us.