Episode Guide

The Mystery of Nan Madol

Giorgio Tsoukalos and David Childress journey to Nan Madol, an 11-square-mile complex of over 100 man-made islets off the coast of Pohnpei in Micronesia, built from an estimated 250 million tons of basalt—some blocks weighing 50 tons each. The episode explores whether local legends about "strange visitors" floating massive rocks through the air might point to extraterrestrial intervention, particularly given the site's reported magnetic anomalies that allegedly interfere with electronic equipment near the ancient walls. Ancient astronaut theorists question why such monumental construction would exist on a remote island 600 miles from anything, and David Childress suggests the structures could be far older than currently believed, proposing that the 1100 AD dating from coral rubble merely reflects repair work rather than original construction.

The Relics of Roswell

This episode revisits the 1947 Roswell incident, arguing that physical evidence of an extraterrestrial crash may still exist in the New Mexico desert. The focus centers on metal fragments held by investigative journalist Linda Moulton Howe since 1996—specifically, a layered bismuth-magnesium-zinc material with micron-thin alternating layers and a sample of unusually pure (99.5%) aluminum. According to Howe's source, these materials originated from the White Sands area outside Roswell. The episode suggests the U.S. Army's recent interest in examining these fragments lends credibility to claims that the military's original "weather balloon" explanation was a cover story for recovered alien technology. Ancient astronaut theorist Giorgio Tsoukalos examines the materials, noting the striking purity and layered structure that Howe describes as resembling "a torte cake" at the microscopic level.

The UFO Phenomenon

This episode explores whether Chile's status as a global UFO hotspot—particularly in the Atacama Desert—might be connected to the region's 5,000+ ancient geoglyphs, nearly five times more than Peru's famous Nazca Lines. The investigation centers on 2019 Chilean Navy helicopter footage of an unidentified craft that even the government couldn't explain, alongside the discovery by a NASA-funded rover mission that same year of microbial life thriving beneath the Atacama's bone-dry surface. Ancient astronaut theorists including Giorgio Tsoukalos and Erich von Däniken argue the massive geoglyphs—spread across 90,000 square miles of one of Earth's harshest landscapes—represent evidence of sustained extraterrestrial contact, with indigenous traditions speaking of "beings who came from outer space." The theorists suggest the desert's Mars-like conditions and unique microbial life may hold clues to why this region would attract non-human visitors across millennia.

The Real Men in Black

This episode investigates whether the "Men in Black"—government agents who allegedly suppress UFO evidence—are real, sparked by a September 2018 incident at the U.S. National Solar Observatory in Sunspot, New Mexico. Armed personnel in black arrived via Blackhawk helicopters, evacuated staff, seized materials, and shut down the facility without clear explanation. Ancient astronaut theorists including Mike Bara argue this fits a seven-decade pattern of intimidation stretching back to the 1947 Maury Island incident in Washington State, where witness Harold Dahl reportedly encountered threatening visitors in dark suits after spotting anomalous aerial phenomena. The episode presents these agents as either a covert government program monitoring extraterrestrial activity or, more provocatively, as non-human "gatekeepers" protecting UFO secrets from public disclosure.

The Alien Engineers

This episode examines colossal stone statues across the ancient world—from Egypt's Abu Simbel to Easter Island's moai—and asks whether they served a technological function beyond symbolic representation. Ancient astronaut theorists, citing the precise astronomical alignment of Abu Simbel's 64-foot statues of Ramesses II and the temple's biannual solar illumination event, propose these monuments acted as "transmitters" that drew down cosmic energy. The episode points to a pattern: multiple ancient cultures, including the Easter Islanders and builders at Copán and possibly Göbekli Tepe, explicitly described their statues as possessing consciousness, power, or spiritual energy called "Mana." Theorists argue this consistency suggests a literal technological purpose rather than mere religious metaphor, potentially knowledge passed down from extraterrestrial visitors.

They Came from the Pleiades

This episode explores whether technologically advanced civilizations existed on Earth tens of thousands of years ago, inspired by a 2018 NASA paper by Gavin Schmidt and astrophysicist Adam Frank that examined detectability of ancient societies. Ancient astronaut theorists including Giorgio Tsoukalos and David Childress point to oral traditions from cultures worldwide—Greek accounts of Five Ages of Man by Hesiod, Aztec cosmology, and early Judaic texts describing pre-Adamite races—as evidence that humanity has experienced cyclical rises and falls over vast timescans. David Childress cites a submerged pyramid city that he suggests must be 50,000 years old based on ocean depth, while Mark Carlotto argues Mesoamerican sites extend archaeological timelines from 10,000 years to tens of thousands. The episode suggests cataclysms erased physical evidence of these earlier civilizations, leaving only mythological memories.

The Shapeshifters

This episode investigates claims that humanity may have originated from the Pleiades star cluster, located 400 light-years from Earth, pointing to the 2017 discovery of 'Oumuamua—an interstellar object detected by the University of Hawaii's Haleakala Observatory that traveled through our solar system at over 195,000 miles per hour. Ancient alien theorists including Giorgio Tsoukalos and Bruce Fenton suggest the cigar-shaped object's unusual acceleration pattern near the Sun, combined with its apparent origin from the Pleiades region, represents a "calling card" from extraterrestrials. Harvard astronomer Dr. Avi Loeb's speculation that 'Oumuamua might employ solar sail propulsion technology is presented alongside indigenous traditions, such as those shared by Leonard Kapahulehua, describing ancestors who "came from the stars," specifically the Pleiades.

The Alien Phenomenon

Season 15's "The Alien Phenomenon" examines the Integratron, a domed structure in California's Mojave Desert that aerodynamics engineer George Van Tassel built in the mid-20th century with the stated goal of extending human life—potentially to the point of immortality. According to the episode, Van Tassel claimed the design came from extraterrestrial visitors who communicated the blueprint to him. Ancient astronaut theorists, including Giorgio A. Tsoukalos, suggest the 16-sided building was engineered to rejuvenate human cells through harmonics and energy capture, functioning essentially as a "battery charger" for the human body. The episode points to Van Tassel's sudden death at 67 and the alleged government seizure of his papers and equipment as potential evidence that his work threatened powerful interests, with family members noting the suspicious cremation before notification and a reported ransacking of his home during the funeral.

The Alien Abductions

This episode investigates whether modern alien abduction accounts—particularly reports of shapeshifting beings—connect to ancient legends of creatures that transform their appearance. The central case is Travis Walton's 1975 experience in Arizona, where the forestry worker claims he was abducted after encountering a disc-shaped craft. Walton describes initially seeing "grey" extraterrestrials, then human-looking beings who he suspects were the same entities in different forms. Ancient astronaut theorists including Giorgio Tsoukalos and David Childress argue this mirrors global folklore about shapeshifters—from vampires turning into bats to creatures stealing human faces—suggesting these aren't myths but historical encounters with extraterrestrials capable of altering their appearance. Nick Pope and Michael Salla propose that aliens use this ability strategically, shifting to human form to calm abductees.

The Providers

In this episode, Ancient Aliens investigates Skinwalker Ranch, a 512-acre property in Utah's Uintah County that researchers and local tradition describe as a concentration point for unexplained phenomena. Ancient astronaut theorists examine reports spanning centuries—from Franciscan monks documenting strange lights over their campfires in the late 1700s to modern accounts of animal mutilations, cryptid sightings, and aerial anomalies. The ranch takes its name from Navajo legends of shapeshifting entities, a curse allegedly placed on the land following the forced removal of Navajo people during the 1864 "Long Walk." Proponents argue the location represents a unique "nexus" where paranormal activity manifests with unusual frequency and intensity, suggesting possible connections to non-human intelligence or interdimensional phenomena.

The Harmonic Code

This episode examines reports of UFOs across vastly different eras, arguing that the variety of shapes—disks, triangles, cylinders—might indicate multiple extraterrestrial civilizations visiting Earth. The inquiry begins with the Nuremberg celestial event of April 14, 1561, documented in a contemporary woodcut, where thousands of witnesses reportedly saw hundreds of strange objects engaging in what looked like aerial combat. A similar mass sighting occurred in Basel, Switzerland five years later, also preserved in a woodcut. Ancient astronaut theorists including Giorgio Tsoukalos and George Noory propose that different craft shapes reflect different origins or functions: scout ships versus mother ships, or vehicles from distinct planetary systems, much like how different nations on Earth build different aircraft designs. Physicist Michio Kaku discusses the extreme g-forces involved in reported UFO maneuvers, while Richard Dolan describes radar returns equivalent to ten aircraft carriers appearing in the sky.

Skinwalker Ranch

Season 15's "The Presidents" episode argues that extraterrestrials may have monitored or influenced American leadership throughout history, presenting what Ancient Astronaut theorists describe as a pattern of presidential UFO encounters dating back to the nation's founding. The episode highlights that 36% of U.S. presidents have allegedly experienced unexplained phenomena—from George Washington's vision of a "glowing, beautiful creature" who supposedly revealed America's future during the harsh winter at Valley Forge, to Ronald Reagan's reported UFO sighting, to Donald Trump's carefully worded 2019 responses about intelligence briefings on unidentified objects. Former U.K. Ministry of Defense investigator Nick Pope and others suggest presidents may possess secret knowledge about alien visitations that they've chosen to withhold from the public, with the episode positing that this silence across administrations itself constitutes evidence of something extraordinary.