Circles from the Sky: Crop circles are a global phenomenon, with 10,000 seen worldwide. But are these strange patterns simply a hoax or could they be proof of UFO activity? (S8, ep 8)

The Great Flood: Experts find evidence suggesting that ancient aliens saved humanity from great floods sent by the gods. Can we rely on extra-terrestrials to save us again? (S7, ep 8)

Aliens And The Red Planet: Experts question what probes on Mars may have found over the past 40 years. Could NASA be hiding proof of life on the Red Planet from the public? (S6, ep 8)

Emperors Kings And Pharoahs: Could ancient rulers have had otherworldly links? Experts examine whether history's most powerful leaders were 'chosen' and guided by aliens. (S5, ep 8)

Einstein Factor: Ancient astronaut experts believe the minds of Einstein and Galileo were superhuman. Could these historical geniuses have had extraterrestrial connections? (S4, ep 8)

Aliens And Lost Worlds: Experts search for proof of alien visitors in the ruins of lost civilisations. Could Mayan carvings reveal a city once ruled by otherworldly beings? (S3, ep 8)

Angels And Aliens: Biblical texts describe winged creatures carrying messages from the heavens. But are angels merely the product of the imagination - or do they really exist? (S2, ep 8)

Creatures Of The Deep: Experts investigate whether alien life forms are thriving in our seas, following Russian cosmonauts' discovery of living plankton in space. (S8, ep 7)

Alien Messages: Could extraterrestrials have left us clues to the universe's mysteries? Experts investigate cryptic puzzles that might have been left by ancient aliens. (S7, ep 7)

Treasures Of The Gods: Across the world, there are stories of treasures that have been lost for centuries. Could these ancient relics have been hidden by extraterrestrials? (S6, ep 7)