Are we alone in the Universe? With more than 100 billion galaxies in the observable universe and at least 500 billion planets ...

A leading biological anthropologist has proposed that the mysterious beings behind countless UFO sightings could be time-travelling humans from Earth's future, returning to monitor their ancestors as ...

The nature of space, time and the evolution of life on Earth mean it’s unlikely extraterrestrial life has visited our home planet.

With the release of "Disclosure Day," Steven Spielberg's new film about aliens, a question as old as science fiction itself resurfaces: If aliens were to arrive on Earth, would they come to conquer us ...

Professor Carol Oliver suggests that time dilation, a cosmic phenomenon, may deter aliens from visiting Earth, as interstellar travel could leave them stranded in a future far from home.