Samantha Rolfe of the University of Hertfordshire writes about the possibility that alien life exists on Earth, but we just can’t see it. Life is pretty easy to recognise. It moves, it grows, it eats, ...

Want to be a top notch candidate for hosting alien life? Then there's a few key requirements you should be aware of: Ideally, you're a large object like a moon or a planet; scientists suspect you also ...