Season 5

Massive stone structures that reach to the heavens... strange, giant figures buried deep in the Earth... and energy emitting spheres connected around the globe... What compelled ancient man to move colossal stones?

They were teachers and destroyers. Mighty warriors who blazed across the skies in gleaming chariots and wielded magical weapons that could bring down mountains. Odin, Frey and Thor.

A young man's spiritual journey. A controversial bestseller. And a scientific theory that threatened to change the world. Just what are the facts behind Erich von Daniken and the Ancient Astronaut theory?

The abduction of Travis Walton in 1975; Travis claims to have been abducted by extraterrestrial beings and taken aboard their space ship.

Erich von Daniken's landmark book, Chariots of the Gods, brought attention to the mysterious phenomena of the Nazca Lines. Hundreds of gigantic lines, some in the shape of animals, geometric patterns and even an alien-like being, extend for miles throughout a remote Peruvian desert. Scholars are divided as to who built them, and why. Some Ancient Astronaut theorists believe that the massive markings have an extraterrestrial connection, and perhaps the ancient people of the region created these gigantic figures in tribute to the gods who visited them. And with one of the largest deposits of nitrates in the world - a key ingredient in rocket fuel and weaponry - could Nazca have been a mining operation for advanced beings in the distant past?

They were the messengers of divine knowledge and seers who shared visions of the future. For thousands of years, human civilization has been guided by the words and deeds of ancient prophets, but just who - or what - were these prophets communicating with? Might the experiences of history's prophets be evidence of communication with a heavenly source - or were seers like Elijah and Joseph Smith actually communicating with extraterrestrial overlords? And if so, are there similar prophets at work today?

Across the globe, archaeologists have uncovered ancient tombs filled with strange items and writings. Remarkable similarities have been found at each of the sites. How is it possible that the burial chambers of distant cultures were so similar in design? Ancient Astronaut theorists believe that some of these complicated and technically advanced tombs were designed with the help of extraterrestrials.

Was Albert Einstein so revolutionary, due to influence of knowledge from teachers from other planets?

Why were many ancient civilizations around the world so focused on the Orion constellation? Some scientists cite earthly connections, but other researchers suggest another explanation "beyond" Earth.

Egyptian hieroglyphs depict the use of light bulbs in tombs and secret chambers. And batteries may have been discovered among artifacts from Mesopotamia. Did the Ancients understand electricity, and if so, how did they discover this technology? Might they have had help from extraterrestrials?

In 1980, three young military men were sent into a UK forest to investigate strange lights. They reportedly encountered a spacecraft of unknown origin.

For thousands of years, pyramids were the largest structures on Earth. The best known were constructed in Egypt and Central America, but others have been found all around the world, including in China, Africa and Indonesia.