As commercial spaceflight accelerates—with Virgin Galactic's SpaceShipTwo Unity reaching suborbital altitudes in 2018 and SpaceX's Falcon Heavy reviving Moon rocket capabilities—ancient astronaut theorists suggest humanity isn't pioneering space colonization but returning to an extraterrestrial heritage. William Henry proposes we're nearing discoveries that will validate ancient astronaut theory entirely, while Linda Moulton Howe claims governmental knowledge of alien intelligence must be disclosed before humans venture beyond Earth. The episode frames Mars exploration as potentially revelatory: theorists ask what happens if colonists encounter artificial structures on the red planet, implying previous civilizations may have left evidence waiting to be rediscovered by descendants unaware of their cosmic origins.
Mainstream space agencies and scientists view the current boom—driven by NASA, China's space program, and private ventures from Elon Musk and Richard Branson—as an unprecedented but entirely human achievement building on decades of engineering and planetary science. No credible evidence supports existing structures on Mars; rovers have found geological formations but nothing artificial. Yet the episode captures genuine wonder about this pivotal moment when, as physicist Michio Kaku notes, we're entering a second golden age of space exploration after the Apollo era's long stall. For skeptics, the compelling question isn't about returning to alien origins but confronting what becoming an interplanetary species—with children born as Martians within generations—means for humanity's future identity and survival.
Island of Crete
Greece · Ancient Greek
Theorists argue that the mythological bronze giant Talos, said to have guarded the island of Crete by hurling stones at approaching ships and incinerating them with heat, was a real functioning robot created by Hephaestus with extraterrestrial technology. Mainstream classical scholars regard Talos as a mythological construct representing the concept of a divine automaton in Greek legend, with no physical evidence of an actual machine.
Khorsabad Palace (Palace of Sargon II)
Iraq · Ancient Near Eastern
Theorists argue that the Sumerian cuneiform inscriptions found at this Assyrian palace describe the Anunnaki as literal extraterrestrial visitors who came from the stars and genetically engineered humanity. Mainstream archaeologists interpret the inscriptions as mythological and religious texts describing the gods of the ancient Sumerian and Assyrian civilizations.
Mars (Gale Crater)
Mars · Solar System
Ancient astronaut theorists argue that methane cycles, organic molecules, and possible subglacial water detected by NASA rovers and orbiters confirm that Mars once hosted advanced extraterrestrial civilization and may have been the origin point of human life. NASA scientists acknowledge the methane cycle could indicate extant biological life but note non-biological explanations also exist.
Mars (subglacial lake, south polar region)
Mars · Solar System
The episode presents the European Space Agency's July 2018 discovery of a subglacial lake beneath Mars' southern polar cap as potential evidence that Mars currently or historically supported life, consistent with the ancient astronaut claim that Mars was once a blue ocean world hosting civilization. Scientists frame the discovery as the most significant evidence yet for a liquid water habitat but note confirmation is still ongoing.
Nubian Desert (asteroid impact site, Sudan)
Sudan · Modern
Theorists use the 2008 Nubian Desert meteorite fall—whose diamond-bearing fragments are believed to originate from a destroyed proto-planet—as physical evidence supporting Zecharia Sitchin's claim that a 12th planet once existed beyond Mars and was destroyed, possibly displacing inhabitants to Mars and then Earth. Mainstream planetary scientists confirm the meteorites suggest a lost proto-planet but make no connection to ancient human origins.