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.

Harvard scientist Avi Loeb says humans are not at the cosmic top table and calls for full release of UFO data, arguing that ...

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 ...