Today, Mars is known as the red planet, for its rust-colored desert landscape. Once upon a time, Mars was a very different place. It had complex waterways and, possibly, ancient aliens. Researchers ...

There’s no denying the allure of alien artifacts. Science fiction is awash in the material remnants of extraterrestrial civilizations, which surface in everything from the classic books of Arthur C.

'Do all aliens really need sunlight?' ...