Elon Musk has turned a long-running joke about being an extraterrestrial into a central part of his public persona, even as he argues that humanity may be the only intelligent life in the universe.

Wondering whether we're alone in the cosmos is almost a rite of passage for human existence. It's a mystery that scientists – and stargazers – have pondered for many years. The Fermi Paradox poses a ...

NASA officials have previously spoken of the possibility of extraterrestrial life amid scientific uncertainty while ...