Somewhere out there, a planet roughly the size of Earth may be orbiting a distant star in conditions that could support life.

The Harvard astrophysicist has devoted years—and thousands of interviews—to the idea that mysterious objects streaking ...

A polarizing Harvard astronomer known for splashy theories about alien visits has been tapped by the White House to lead a ...

An unusual sighting in a NASA image has reignited speculation that something extraterrestrial once existed on Mars.

Case in point: Scientists from Tokyo University and Hokkaido University in Japan stumbled across some mysterious jet-black ...