UFO sightings over nuclear facilities trigger high alert responses - are they top-secret aircraft or something from another world?

An investigation into triangular-shaped UFOs seen in the 1980s and 90s - they might be the best evidence of extraterrestrial crafts?

Anti-aircraft guns blast the skies over Los Angeles when an unknown flying object is spotted by thousands in 1942 - is it from earth or could it be extra-terrestrial?

Roswell is the most famous UFO story in history and a piece of debris found at the desert crash site might shed new light on what really happened in 1947.

True stories of fighter pilot encounters with unidentified flying objects in our skies – including pilots who were ordered to ‘shoot ‘em down’.

Well-documented sightings of UFOs by commercial airliner pilots may be proof of danger lurking in our skies.