Ufologists look why Scotland has the most UFO sightings in the world.
July the 16th, 1945, the day the atom bomb exploded. But some people believe it was also the day an alien conspiracy to take over our planet began.
Many believe that a blood-sucking alien hunts the jungles of Latin America.
Experts look at otherworldly technology used to build ancient structures.
Experts look at the theory that aliens are running humanity's daily lives.