1. Red Alert

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

2. Black Triangles

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

3. Battle of Los Angeles

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?

5. Shoot 'em Down

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

6. UFOs vs. Airliners

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