Ancient Aliens

Experts investigate remote ruins, mysterious caves and legendary mountain portals. Could these alleged stargates have brought ancient aliens to Earth? (S6, ep 5)

Experts investigate strange carvings from 8,000 BC and unexplained sightings in the New World. Is there more to the US's past than history books suggest? (S6, ep 4)

Experts comb history for evidence of children with strange abilities and great knowledge. Could these young people have been born from ancient aliens? (S6, ep 6)

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)

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)

Throughout history, spiritual leaders known as shamans have healed, protected and advised. Could they really be in contact with extraterrestrial realms? (S6, ep 9)

Could insects have descended from extraterrestrials? Experts investigate whether Earth's 10 quintillion critters could have dangerous links to aliens. (S6, ep 10)

Theorists ask whether a currently unidentified species represented in our DNA could be a result of breeding between humans and aliens in the remote past. (S6, ep 11)