We're counting down the world's top ten alien encounters, from the first reported abduction event to mass UFO sightings over New York's Hudson Valley to an incident in ancient Rome that changed the course of human history. Could these incredible accounts be actual encounters with visitors from the stars?

Ancient Aliens Season 15 Episodes...

• s15e01 - The Mystery of Nan Madol
• s15e02 - The Mystery of Mount Shasta
• s15e03 - Top Ten Alien Cover-Ups
• s15e04 - The Mystery of Mount Shasta
• s15e05 - The Human Experiment
• s15e06 - Top Ten Alien Encounters
• s15e07 - Top Ten Alien Artifacts

Ancient Aliens Show Summary

Presented in the 1968 bestselling book Chariots of the Gods by Erich von Daniken, the theory of "ancient aliens" rocked people's beliefs in mankind's progress. Ancient cave drawings of strange creatures, remains of landing strips in Peru, and Indian texts that describe the "flying machines of the gods" were just a few of the odd archaeological artefacts cited by von Daniken as proof that ancient astronauts were well known to our ancestors. Produced with the exclusive cooperation of von Daniken himself, Ancient Aliens launches all-new expeditions to seek out and evaluate this evidence, with a concentration on the latest discoveries of the last 30 years, including unusual DNA findings on man's evolution and newly decoded artefacts from Egypt to Syria to South America. It is a balanced investigation into a theory some believe cannot be true, but many agree cannot be ignored.

** Please Note: the schedule for Ancient Aliens is a 'best fit'. The official order has changed multiple times, and no one source agrees with another **