Extraterrestrial Life

For most of us, aliens are a source of mystery and fun, which keeps them forever in vogue

The discovery that life on Earth looks a lot like information propagating itself offers new clues, and new directions, to the hunt for life elsewhere

Human intelligence may be just a brief phase before machines take over. That may answer where the aliens are hiding

Cell-phone towers leak radio waves into space, but they’ll be tough for aliens to detect

Hints of life on distant worlds will come from signals pioneered by NASA’s jumbo space telescope

For centuries, scientific discoveries have suggested humanity occupies no privileged place in the universe. Now, however, studies of worlds beyond our solar system could place meaningful new limits on our existential mediocrity

The hunt for Martian life focuses on detecting organic molecules that could indicate its past existence. Are our instruments up to the task?

Do efforts to create life—by cooking up imitations in computers, robots and molecules—point toward a universal definition of biology?

Collisions between moons and planets may be a regular danger for possible extraterrestrial life

Science might be redefining what “life out there” really means.

By shunting pilot observations aside, the Pentagon likely fostered a UFO fad and overlooked Chinese intelligence technology entering U.S. airspace

A new European mission is the first of two spacecraft—with the other coming from NASA—that will hunt for signs of habitability on Jupiter’s icy moons