Ancient Astronauts



"Mary: Did you build the Pyramids?

Dick: Only the one in Las Vegas.

Mary: What about Easter Island?

Dick: Easter Island was a practical joke that got out of hand."

- 3rd Rock From the Sun ("The Thing That Wouldn't Die: Part 1")

Science Fiction trope wherein ancient locations, legends, gods, and creatures from ancient myth are connected to alien visitors from a radically more advanced civilization. This trope includes that these aliens influenced our history in some way, mostly through technological advances. Often these aliens are Sufficiently Advanced Alien.

When this trope kicks in, expect various myths to be actually related to aliens. Everyone knows about Clarke's Third Law: the many legends of magic, gods, beings coming from the sky and the like were actually based on alien technology that we cannot comprehend at that time.

Proponents of this theory also espouse that ancient construction projects like the pyramids and Stonehenge are clearly too advanced and a little too fantastic for ancient man to have constructed without help from a more advanced civilization. Or That there are pyramids in the Americas, Egypt, and China... you guessed it, they all got their idea from aliens. Other popular sites include the the Moai of Easter Island and the Nazca Lines.

Popularized by Erich von Däniken's 1968 book Chariots of the Gods and its various sequels, which stridently insist that a careful blend of selected archaeological evidence will reveal that this very scenario happened in reality. The Real Life evidence for this, however, is little. However, if it's brought up in fiction, expect these theories to be always right on the money. After all, it's not like either aliens or ancient humans would be interesting enough to write fiction about on their own, without them interacting, would they?

This theory is often crossed over with Atlantis. Essentially runs on Mistaken for Gods; contrast with And Man Grew Proud. May result in Boldly Coming. If the unknown ancestors sport special abilities which aren't derived from technology, compare Our Ancestors Are Superheroes. Usually overlaps with Neglectful Precursors, as the aliens are generally implied to have lost interest in humans and/or concluded we're unworthy successors, ages ago.

Ancient Astronauts are very frequently builders/users of Sufficiently Advanced Bamboo Technology.

Anime & Manga

 * Urusei Yatsura presents a number of beings from Japanese myth as aliens.
 * Nadia: The Secret of Blue Water utilizes the Atlantean subtrope.
 * In the manga version of Chrono Crusade,
 * It's hinted that Kabapu and Il Palazzo of Excel Saga (and possibly Excel herself and the Ropponmatsu), are connected to a lost civilization called Solaria, which may well be an example of this. Particularly as Tenmangu Shiouji didn't believe their technology could be created on Earth. And if it can't be created on Earth that kind of leaves only one option...
 * Shiouji's son Goujo actually states this Trope by name while ridiculing the idea that Kabapu's claims as to his origins are true.
 * In the manga Paradise on the Sand, the ruling class of the unnamed pseudo-Middle Eastern country in which the story is set believe that they once lived in Heaven with the gods, but were eventually banished, and told that if they kept their blood pure they would one day be allowed to return. In addition, the enigmatic character Raisa is heavily hinted to be a goddess come to check up on them.
 * It's unsure (intentionally, most likely) how much of the aliens mentioned in back story documents for Neon Genesis Evangelion fits this trope and how much is just plain old Precursors. The aliens don't seem to have actually visited Earth, for one thing. However, they are responsible for not only the Angels, but . Given that there are conspicuous amounts of mythological symbolism (both Christian and non-Christian) in the series, one is tempted to think they influenced Earth culture in some way as well.
 * It's specifically mentioned that
 * In Spriggan, one of Yu Ominae's missions in Mexico reveals that the gods the Mexicans worship in the old days are actually ancient astronauts. With some exceptions.
 * Not to forget an early chapter/in the OVA movie in which ARCAM scientists discover Noah's ark
 * In One Piece this appears as well (to some extent). Although never explained in detail a number of technologically advanced winged humanoids lived on the Moon (the Skypieans, Shandians and Bilkan), when resources ran out they departed the moon. Upon initially seeing them they were mistaken for angels, and their shadows (from those that lived in the clouds) were often mistaken by sailors as being the silhouettes of giants.
 * The Protoculture of Super Dimension Fortress Macross is presented as such in the prequel Macross Zero, when it's revealed they have influenced the culture of the people of Mayan Island (it's also hinted they interbred with them) so they would be able to activate an artifact that would either bomb mankind back into stone age if they reached space before renouncing to war or provide Protoculture technology if they did renounce war. Humans being humans and the Anti-UN having just bombed Mayan Island before it was activated, the Bird Human immediately arms the Wave Motion Gun.

Comic Books

 * The Tintin story Flight 714 takes place on an island regularly visited by Ancient Astronauts and their "initiates" right up to the present day.
 * A borderline example: in the Marvel Universe, the Sphinx was a time machine created by Rama-Tut, a human time traveler from an alternate timeline's future.
 * An 1971 Incredible Hulk story had the Sphinx being left behind by aliens as a weapon
 * Inverted by X-Men villain Apocalypse. Being an immortal mutant shapeshifter with access to alien technology, he would claim to be various deities in order to more thoroughly dominate whatever group of people he was subjugating at the time.
 * The Eternals are a super-powered, immortal human-offshoot race created by ancient astronauts, and were often mistaken for gods. Their Always Chaotic Evil counterparts, the hideously mutated Deviants, were the inspiration for many mythical monsters and demons.
 * A more straightforward example in Marvel Comics is the Earth X trilogy, which states that all the "Gods" in the Marvel U (the Asgardians, Olympians, Egyptians, etc.) are Ancient Astronauts who were shaped into their current forms by humans' beliefs.
 * In Wild CATS, it's implied that the immortal alien Kherubim and body-snatching Daemonites (note the names) are the inspirations for many Earth legends.
 * In the Elf Quest series, the elves' ancestors came to the World of Two Moons because they discerned signs of their own kind in native humans' art and culture, and wondered if their species had been there in the past. This became a self-fulfilling prophecy.
 * Bec and Kawl from Two Thousand AD featured a story about a race of aliens resembling traffic cones that apparently forced all the ancient humans into slavery for the sole purpose of building building conical monuments to them. Humans eventually rebelled and after the aliens fled the planet, the humans developed basic geometry and modified the alien monuments to show this (explaining the likes of the Egyptian and Aztec pyramids and Stonehenge). Presently, the aliens are hiding amongst us disguised as, you guessed it, traffic cones.
 * A Sam and Max Freelance Police short had them going into the past and thwarting Egyptian aliens. Like everything else in the series, purely played for laughs.
 * In Grant Morrison's Seven Soldiers and Final Crisis, the New Gods are revealed to have visited Earth during the prehistoric era, influencing human culture and providing humans with technology.
 * In the post Infinite Crisis retcon, the Daxamite race, an off-shoot of the more famous Kryptonian race with the ability to interbreed with human, has been shown sending their explorer on Earth, in ancient times. Due to Daxamites and Kryptonians gaining Superman-like powers from a yellow sun, they gave themselves a strict no sex rule. That didn't prevent them from passing down the history af the Gods of the Mesoamerican pantheon.
 * Actually, some Daxamites were more lax than others in self-discipling themselves. While some of their offspring lead humanity to formulate legends about demigods and other mythical heroes, a particular Daxamite, Bal Gand, escaped back on Daxam, programming her ship to carry her Halfbreed future son back to Earth if he was ever ostracized for that.
 * He didn't, but many centuries later, during a xenophobic upheaval on Daxam, her descendant Lar Gand found the ship meant for his ancestor, crashlanding in Smallville, home of a certain Clark Kent...
 * Although literal Chinese dragons do exist in the Marvel Universe (thanks to Iron Fist's backstory), Marvel's most well-known ancient "dragon" is a giant alien named Fin Fang Foom.

Fanfiction

 * In Divine Blood The Demons and Gods are basically previous evolutions of sentience and then immortality that developed on Earth and then left to extradimensional safe havens to avoid some extinction level events. Frequent interaction with humanity has caused them more or less to assimilate to human culture to the point where even the basically down to Earth human-friendly set think of Demon and God as their species name.

Film
"Walter: Everyone else said, "use the North Pole," and I said, "no, too cold." Sinking never occurred to me."
 * Stargate showed that the sun god Ra had actually been.
 * Spoofed in Ice Age when the prehistoric main characters pass a giant Flying Saucer frozen in an ice cave. Bonus points are awarded for having the Neanderthal baby flash the Vulcan salute at it.
 * Indiana Jones and The Kingdom of The Crystal Skull.
 * But when the evil but hot KGB Agent tried to have all this knowledge downloaded into her brain... But it was too much for the human physique and she was incinerated in the process.
 * Mission to Mars reveals the origin and purpose of the mysterious face on Mars The fact that later, higher-res photos proved in real life that the Mars Face doesn't actually look anything like a face slightly ruins the effect.
 * Who cares, it's fiction anyways.
 * Also somewhat explained with a line from Luke to the effect that the face, having been buried in dirt in the intervening millennia since its construction, looks somewhat different than its architects intended. Indeed, when, one of the side effects is a nice dusting. (One wonders why the aliens wouldn't have taken erosion and weather patterns into account when building it, but there you go.)
 * Alien vs. Predator actually provides a rationale for why the visitors were regarded as godlike beings but still only influenced humanity in the pyramid-building direction: Earth was a rite-of-passage hunting ground, only visited once every century in designated sites built for the purpose. Occasionally, things got out of hand and the visitors had to resort to continent-blasting weapons.
 * For previous uses of this in the Predator canon, don't forget Predator 2, and the antique flintlock from the 1600's, kept as a trophy and given as a gift.
 * The indirect Alien prequel Prometheus deals with the mystery of the space jockey, revealing that it is a  The movie opens with one such being on earth,
 * Revenge of the Fallen has the Seven Primes, who came to northern Africa about 19,000 years ago, The Fallen built the Solar Harvester, got into a war with his fellow Primes for possession of the Matrix. He wanted to kill all humans and get loads of Energon while at it. His brothers hid the Matrix of Leadership in a tomb made of their own bodies, a tomb the Fallen's Decepticon Seekers cannot find. Seymour Simons believes various ancient archeological sites has evidence of Transformers visiting due to cybergylphs. The Ruins of Petra turns out to be the Primes tomb and the Pyramid of Giza as the Solar Harvester in disguise.
 * Implied in 10,000 B.C.. The slaves say that The God of the Pyramid came down from the stars.
 * Others say he's from Atlantis, so we get two common flavors of this trope.
 * It could both be true, actually.
 * Used in 2001: A Space Odyssey, when Prehistoric Man discovers The Monolith. See the "Literature" section.
 * In Cocoon, Atlantis was the Antareans' first base on Earth.


 * Although the recordings are garbled and only half-translated, this seems to be the case in The Fourth Kind: the aliens claim to be the creators, and abductions throughout history are somehow related to "testing" humanity's worth. In the end, they even claim to literally be God.

Literature

 * A variant: In the Dune universe, the Bene Gesserit (selective breeders of humanity) spread myths around various planets to help out their members, should they need assistance.
 * As pointed out in the All Myths Are True entry, this turns out to have not been the best idea they ever had, especially as they're attempting to breed The Messiah.
 * One of the earliest examples of this trope (perhaps the earliest) was in Edison's Conquest of Mars, an unauthorized sequel to War of the Worlds written in 1898, where Thomas Edison invents a spaceship and launches a counterattack against the Martians. Here, it was revealed that the Martians built the Pyramids and the Sphinx. This makes this Older Than Radio.
 * HP Lovecraft popularized this trope in At the Mountains of Madness, which reveals that ancient aliens who lived on Earth before humanity inspired the ancient legends that Lovecraft hinted at in earlier, more fantastic stories...
 * The Great Race of Yith is another example, and Cthulhu and the other Great Old Ones are alien (possibly extradimensional) beings that came to Earth eons ago. However, they aren't just worshiped as gods, they actually are ones (what else would you call a immortal, immensely powerful being that can bring about the end of the world on whim?).
 * But it was the Elder Things (also often called the Old Ones) that started the life on this planet. Why? To get meat and slave-labour. Or by accident, or as a joke.
 * David Gerrold and Larry Niven's novel The Flying Sorcerers neatly serves this trope, by having a human explorer be stranded on a distant planet through the actions of primitive aborigines that think he's a magician -- an invading magician. He is forced to enlist their help to get to a location on their planet where he can signal his orbiting mothership for aid -- and to do so, creates all sorts of legends in the process, as he is forced to teach the aborigines such principles as electricity and airtightness, to fashion a powered balloon to get him where he needs to go.
 * He also "invents" interchangeable parts and money; if he'd only had the good sense to Ayla with him, he'd have also been able to manage sex-toys, the steam engine, and double-entry book-keeping.
 * It does help that the explorer just happens to be based on.
 * Arthur C Clarke's Childhoods End invokes this, but.
 * Also in Clarke's more famous work 2001: A Space Odyssey the Precursors brought to Earth The Monolith that would accelerate the evolution of primitive hominids.
 * William H. Keith (writing as Ian Douglas) uses this three times in his Heritage Trilogy and its sequels. First the cybernetic or mechanical Builders tinkered with the ancient human genome to create Homo erectus and then Ahn who used human slaves in ancient Mesopotamia and finally a third species who helped humans get back on their feet after the Ahn were wiped out.
 * Larry Niven did this a few times; the Pak actually were humans, or at least humans were a variant of the Pak, it is implied that the Thrintun were the source of the beginnings of life on Earth, and a non-Niven story set in Niven's world mentions an abortive Kzin visit resulting in myths about particularly nasty tigers.
 * To expand on the above: humankind are the descendants of a Pak Lost Colony that got set back to non-sentient levels of intelligence for a few million years due to a lack of thallium oxide in Earth's soil (they need it for a specific bacterium that evolves them and us to the "adult" stage of life). The Thrintun created life on earth by seeding it with food yeast, then dying out before they could send in the harvesters that kept the yeast from mutating.
 * The Heirs Of Empire series by David Weber has all of Earth's humanity be descended from the marooned crew of a spaceship after a partially successful mutiny (the spaceship in question is in fact disguised as the moon).
 * In James P. Hogan's Giants series humanity was accidentally uplifted by aliens from Minerva (which was the fifth planet in the solar system before it was blown up).
 * In the German sci-fi series Perry Rhodan, Atlan the Arkonide (more than 10,000-year-old and immortal due to some Applied Phlebotinum granted to him by a Sufficiently Advanced Alien Energy Being) is supposed to be responsible for some of the oldest human myths, like the Epic of Gilgamesh. In one of the spin-off novels, we can even see Atlan acting like a god in front of primitive humans. Atlan's people the Arkonides build their first colony on the famous Atlantide landmass.
 * Actually the Arkonides, during their early space-empire-building phase, originally founded a colony on Venus when they first found the Solar System, because Earth (or Larsaf 3 as they called the planet) had technologically primitive humans on it. When an attack by another race of aliens, the Druuf, forced the Arkonides to abandon their Venus base, the surviving soldiers and settlers were relocated to Earth, where they founded their new colony of Atlantis, named after their commanding officer Atlan. When the next wave of attack hit Earth, Atlantis was destroyed, and while some of the colonists were evacuated, a number of soldiers as well as Atlan himself were left stranded on Earth and scattered, with the surviving Arkonide soldiers intermarrying with humans of stone-age and bronze-age cultures, and Atlan trapped in an underwater station where he put himself into cryostasis sleep when no rescue ship from home arrived (the reason no help arrived was that at the time there was a brutal war going on between the Arkonides and another alien race, the Maahks, so administrators on Arkon kind of forgot about Atlan and the Larsaf-system altogether). Atlan ordered the station's positronic brain to wake him up every few centuries so he could check out how the native cultures were doing and tried to boost their technological progress in the hopes that some millennia later the humans of Earth would have advanced far enough to build spaceship capable of taking Atlan home to Arkon.
 * Centuries after the first manned moon landing had brought official first contact between Earth and Arkon, Perry Rhodan and Atlan went on an expedition to the Andromeda galaxy and found out why Arkonides and Terrans (humans from Earth), as well as a number of other humanoid races of the galaxy, were all genetically compatible. Turns out they were all descendants of the First Mankind, the Lemurians, who had evolved on the continent of Lemuria on Earth! After the Lemurians invented space-travel they colonized most of the Milky Way, before some 50,000 years ago a war with aliens as technologically advanced as themselves forced them to flee to Andromeda. Earth humans were actually the second Mankind, descended from degenerate Lemurians, while Arkonides were descended from Lemurian colonists who had lost most of their high technology. (And some revisionist history censorship by the first emperors of Arkon ensured that millennia later the Arkonides did no longer remember being a bunch of mere colonists). In the Perry Rhodan series, the Ancient Astronauts actually originated from Earth!
 * It actually gets much worse than that. Not only was Earth the home of a vast interstellar Empire 50,000 years ago (Lemuria) and the site of a colony of descendants of that empire 10,000 years ago (Atlantis), it was also visited by aliens both with Earth-ancestry and without before during and after these events. There were significant alien presences at many times in Earth's history and at this point is hard to say if there are any myths left that can not be traced to visitors from the stars.
 * The sheer amount of ancient astronauts that have visited Earth in the Perry Rhodan Universe is perhaps better understood if one realizes that Clark Dalton one of the creators of the series actually was a friend of Erich van Däniken and the two actually wrote a sci-fi novel together about the topic of ancient astronauts.
 * The Takers, a modern Two Fisted Tale by Jerry Ahern. The log of a 19th century expedition seeking Atlantis mentions a horned 'demon skull', which sends the protagonists (and the villain) off on their quest. They discover
 * Subverted in the Animorphs books. It is hinted at pretty heavily, and it turns out that Earth has been visited by aliens countless times throughout history (FYI: Aliens killed the dinosaurs. With an asteroid. That they were using to attack other aliens that had settled on Earth. Oh, and those first aliens? They were ants.), but each time a major revelation is set up it is immediately torn apart. Eric, a Chee (Ageless android living in disguise amongst humanity), reveals that he helped build the pyramids. When he is given shocked stares at the revelation that he created the darn things he laughs it off and explains that he was a slave who helped haul the bricks, he had nothing to do with the planning, engineering, or logistics of the project (He did, however, cut and style Cleopatra's hair a few centuries millennia later). Despite all the aliens who seem inexplicably drawn to our blue planet, all the credit (and the blame) of our history goes to us.
 * The Ellimist plays it straight... just not with humans. He assisted the Hell out of the galaxy, and it's heavily implied the Andalites were included (though how much he helped them while his organic proxy was living with them is unclear).
 * Used, with time travelers rather than aliens, in Poul Anderson's Time Patrol story The Sorrows of Odin the Goth. The time-traveling historian Carl knows that his travels among the Goths are liable to make the natives think he's a god, so he dresses in such a way that stories of his exploits would be folded into the preexisting mythology of Wodan (aka Odin). It doesn't work out quite how Carl intended it...
 * The trope-savvy Game Masters of Dream Park used this as a premise for their live-action adventure tournament in The California Voodoo Game.
 * Possible but unconfirmed in David Brin's Uplift series. Every alien race after the Precursors was uplifted by another species and most refuse to believe that humanity evolved sapience naturally. Rather they claim that humans must have been abandoned by an irresponsible patron race before their uplifting was complete (this has apparently happened before in galactic history, such "wolfling" races tend to destroy themselves before reaching space).
 * On Earth there's "Danikenites" and "Darwinists," the former wear togas to protests while the latter dress like cavemen.
 * Averted in the insulting humans sense in an Asimov short story. Spaceships are forbidden to trade with cultures that don't have anything to offer. A quick scan of the planet convinces most of the crew that humans are just a simple hunter gatherer society, but the trader's instinct says that they do have something to offer. Played Straight in that the traders do help them, giving them the wheel and tools, but the traders gain something by learning to use caricature and sketches from the human's ancient art. Sketches have an advantage of highlighting characteristics that are important, and getting rid of information that is unimportant. The space-faring culture had forgot (or never had) times without photo-realistic holograms.
 * Edgar Allan Poe's "Some Words with a Mummy" pokes fun at the then-common theory that Egyptians couldn't have built the pyramids without outside help: a revived mummy reveals to a group of scientists (all proponents of said theory) that his people not only built the pyramids on their own, but developed all kinds of crazy advanced technology which has since been lost -- all without any interference at all, be it supernatural, alien, or European.
 * In The Science Of Discworld, a band of early hominids is saved from a leopard, then introduced to the concept of "fire," by a wise and civilized visitor from another universe. In this case, it's the Librarian, who (ironically) had been pushed onto an evolutionary course away from humanity when he was turned into an orangutan.
 * In Catherine Asaro's "Saga of the Skolian Empire" books, someone took a group of humans from Earth around 4000 BC and transplanted them to a faraway planet (much like Stargate SG 1). These humans rediscovered spaceflight (twice -- once thousands of years ago, and again around the 1600s AD) and so were already spacefaring when Earthlings finally left home. Unlike many examples of Ancient Astronauts, though, whatever ancient race did it disappeared, and had no further dealings with Earth or the transplanted humans.
 * The reason Artemis Fowl can translate the fairy language so easily is that it is similar to Ancient Egyptian, and Artemis comments this is because the Egyptians borrowed it from the fairies.
 * Out of the Silent Planet inverts this. CS Lewis' Author Avatar translates a manuscript by the 12th century Platonist Bernardus Silvestris, describing a voyage through the heavens and mentioning Oyarses, a tutelary spirit assigned to a planet. Said author avatar seeks translation help from Dr. Ransom--who had himself recently voyaged to Mars and spoken with Oyarsa, and thus recognizes Silvetris' account as a true one. As for Oyarsa, he's an Energy Being and an angel.
 * Fred Saberhagen's The White Bull invokes this trope to explain the minotaur legend. He's also used it with a not-so-ancient classic: in The Frankenstein Papers, the creature turns out to be an alien scholar who'd been snooping around the mad doctor's lab, curious about his electrical equipment, and been rendered unconscious and amnesiac by an accidental discharge.
 * In Septimus Heap, the fifth book mentions that people in the past travelled to the Moon.
 * Inverted in Dragons Egg, where mankind inadvertently jumpstarts a civilization: the barbaric Cheela, seeing a new, wandering star in the sky (an orbiting human vessel), mistake it for a god and develop astronomy and writing in order to follow it. This starts their technological development and they eventually make First Contact. As a bonus, since the Cheela's Bizarre Alien Biology puts them on a different temporal plane, they manage to do it in days.
 * In The Wild Boy, it's indicated the Iani, the creatures who created the Lindauzi, also visited Earth and possibly spawned humanity-the two races are definitely related somehow.

Live-Action TV

 * Stargate SG-1 takes this to its logical extreme. Virtually every culture's gods or mythic figures (right up to King Arthur) have, in the course of the show, been revealed to be inspired or coopted by aliens of one form or another. Mostly, they were the Goa'uld, which began as the Egyptian gods and spread from there, though the benevolent Asgard were the Norse gods, and Merlin was a Sufficiently Advanced Alien. The Christian God has been notably absent, though one Goa'uld was posing as Satan.
 * To be fair, however, the Goa'uld were evicted from Earth before the beginning of Christianity. The Goa'uld posing as Satan, had started out posing as the Egyptian Seker, and just slowly morphed into a version of the devil from there, and he would naturally assumed to be so by Christians offworld.
 * While Stargate has pointedly avoided addressing the Judeo-Christian God directly, presumably to avoid offending "certain people," it can be easily argued that the Ori are representative of the darker side of Christian history, particularly the Crusades and Inquisition.
 * Such events have occurred in the histories of many religions that were "spread by the sword."
 * This was alluded to when Daniel explained how there is a point in human history where humans suddenly stopped worshiping fire (a representation of the Ori) and started worshiping pure white light (a representation of the Ancients, which are pretty angelic like)
 * SG-1 have also shown some Goa'uld posing as Greek Titans and Oriental gods, as well as Mayan crystal skulls as alien communication devices, and Aztec having their own alien descendants and ancestors. For example, the Mesoamerican deity Quetzalcoatl is actually a giant alien made out of smoke.
 * One episode had the characters find themselves in what appeared to be a standard medieval Christian society. They immediately and flatly drop the possibility that a Goa'uld is posing as God - Teal'c says no Goa'uld would be capable of the acts of compassion from the Bible.
 * Which is odd given at least one Goa'uld Mother proved 'perverse' by the standards of the rest and produced a line of symbiotes that were true companions to their human hosts rather than enslaving them. With the example of at least one turning benign the statement that none could become so compassionate seems off.
 * The lost city of Atlantis wasn't sunk or lost: it launched into space and traveled to another Galaxy, eventually settling on a new planet. And then it was sunk, in order to hide it from the Wraith. The remaining Ancients traveled from Atlantis back to earth and presumably told the story of Atlantis to the ancient Greeks. Only leaving out that it was on another planet, in another galaxy.
 * Star Trek the Original Series has had a few of these, most notably Apollo (and by reference the other Olympians) and Quetzalcoatl.
 * "Who Mourns for Adonais" is the episode featuring the alien claiming to be Apollo. "Plato's Stepchildren" is an episode featuring aliens who so admired classical Greek culture that they adopted it as their own. So the aliens from "Plato's Stepchildren" have only two degrees of separation from the aliens from "Who Mourns for Adonais"!
 * Kirk himself becomes a type of Ancient Astronaut in "The Paradise Syndrome", giving the transplanted Native American tribes knowledge of medicine, irrigation, and agriculture.
 * Humans also are Ancient Astronauts in the TOS episode "A Piece Of The Action": a text on Chicago gangs of the 1920's was accidentally left on Sigma Iotia II a century earlier. It subsequently became regarded as a holy book, and the inhabitants built their entire civilization around its depiction of gangland culture.
 * Star Trek Voyager
 * In the episode "Tattoo", Native Americans were barely intelligent cavemen until they were genetically uplifted by ancient aliens.
 * In the episode "Blink of an Eye", the crew of Voyager become Ancient Astronauts to a civilization on a planet that exists in enormously accelerated time; from the viewpoint of the planet, Voyager is in their sky for basically the sum total of civilization, and eventually they advance their technology to the point where they can go out into space to meet them.
 * The aliens don't know about the time dilation though, and by the time the explorers make contact it's more than a generation later on the planet and they start trying to shoot down the alien ship that so callously destroyed their peaceful explorers. The ship is only saved when one of the explorers goes back to explain things, then returns to Voyager with ships specifically built to move Voyager out and break the time acceleration.
 * Another Voyager episode involves a race of aliens who used a naturally occurring network of dimensional tunnels to carve out an empire. When their oppressed subjects eventually overthrew them, some retreated into cryostasis to wait for a more opportune time. By the time of the series, most cultures in the Gamma Quadrant only remember them as cruel trickster demons in a few very old legends.
 * Star Trek the Next Generation
 * The episode "The Chase" winds up establishing that
 * Subverted by an episode where a con artist reads the myths of an alien world and realizes that modern technology is capable of providing all the signs and wonders she'd need to impersonate one of their deities.
 * The 1970s Battlestar Galactica, having been produced at the height of the craze, strongly implied that this was the case in its universe, as the Galactica encounters sufficiently advanced aliens with more than a passing similarity to angels as perceived in the Mormon religion. The 2000s series goes a step further, explicitly identifying the "Lords of Kobol" with the Twelve Olympians of classical Greek mythology, though how the Colonial religion and Greek religion are linked has yet to be explained.
 * The Colonials themselves, if their costuming is any indication, are also meant to be Ancient Astronauts or at least some sort of Precursors. Their starfighter pilots wear "Pharonic" helmets evidently meant to have inspired Tutankhamen's burial mask, and bridge officers wear a very distinctive octagonal cloak, like the classical Greek chalmys.
 * The missing 13th colony, which they're looking for, is Earth.
 * Doctor Who featured this in several stories;
 * "The Daemons" reveals the existence of a race of aliens that resemble demons from classical art, and suggests that they were objects of worship for ancient and medieval pagans.
 * Death to the Daleks. The Doctor suggests the Exxilons might have traveled to Earth and taught the Peruvian Incas how to build their pyramids, as they were too 'primitive' to do it themselves.
 * "Pyramids of Mars" identifies the Egyptian gods Sutekh and Horus as alien warlords, the mythological account of the war between them being a recollection of their actual conflict.
 * In "The Satan Pit," it hung a lampshade; The Beast claims to be an Ancient Astronauts version of the Devil, but the Doctor is highly skeptical, pointing out all the various examples of the trope in different cultures on different planets. Russell T Davies describes this episode as a "sequel" to "The Daemons."
 * It's also left ambiguous as to whether the Beast actually is the Devil (as in, the real deal) or is a Sufficiently Advanced Alien who has just served as the inspiration for that mythological archetype throughout the ages and galaxies.
 * Battlefield implies that a future regeneration of the Doctor
 * The X-Files did this a fair bit in its Myth Arc episodes.
 * In a bit of a twist, the ancient astronauts were the first intelligent creatures of earth. They just left for some reason, and came back to find hairless monkeys had taken over their spot.
 * The Vorlons in Babylon 5 appear to have inserted themselves into the mythologies of dozens, if not hundreds, of planets. When Kosh exits his encounter suit to save Capt. Sheridan's life in the season 2 finale, everyone watching sees him in the form of an angel as depicted in the respective religions of their people. The sole exception is Londo, who sees nothing -- due to the Centauri being historically patronized by the Shadows instead
 * Londo's favorite expression of dismay is "Great Maker." Take from that what you will.
 * Londo was also shown explaining and celebrating his peoples faith. There is no evidence that he was magically an athiest because some people want him to be.
 * Presumably, worlds where the Vorlons never put in an appearance simply wouldn't have angels as part of their mythology.
 * On Smallville, tales of a Kryptonian visitor were the foundation of a Native American religion.
 * The 1958 BBC TV serial Quatermass and The Pit (and the 1967 movie based on it) has the premise that beliefs in witchcraft and demons stemmed from the arrival of Martians early in Earth's history.
 * The 1979 sequel serial Quatermass reveals another race of aliens is responsible for the existence of Stonhenge and other ancient stone rings.
 * The crew of Space Island One encounter a Babylonian space probe.
 * Kolob in Children Of The Dog Star is one of three alien space probes from Sirius that imparted advanced knowledge to ancient people, including the Dogon.
 * This notorious gentleman from the History Channel. "I'm not saying it was aliens, but... IT WAS ALIENS"
 * Features rather prominently by the end of Tracker. Cirronians visited Earth, hid the Vardian Doomsday Device to keep it safe, and interbred with humanity to create a guardian line. Cole also mentions things like Stonehenge and the Pyramids when he explains things to Mel. Most Migar folk belive it's a myth by the time of the series, but Mel and Cole find it's all true.
 * Features rather prominently by the end of Tracker. Cirronians visited Earth, hid the Vardian Doomsday Device to keep it safe, and interbred with humanity to create a guardian line. Cole also mentions things like Stonehenge and the Pyramids when he explains things to Mel. Most Migar folk belive it's a myth by the time of the series, but Mel and Cole find it's all true.

Music

 * Paul St. John's Flying Saucers Have Landed is a musical tribute to this trope.

Newspaper Comics
"1) Alien arrives and is worshiped as a god by primitive humans
 * Parodied in a Brewster Rockit sequence showing ancient drawings depicting events such as:

2) Alien explains to primitive humans that he is not a god but a being like themselves

3) Primitive humans pelt alien with stones for not believing in their god."

Tabletop Games

 * The Warhammer 40000 gives this trope an interesting twist by combining it with a God Guise and then wrenches it a bit further: the ancient astronauts in question are in fact the original human settlers of the various human planets, of whom knowledge was lost during any one of the several galactic dark ages, and most primitive humans thus regard the humans and technology of old as worthy of worship. The Imperium of Man and Adeptus Mechanicus think they have the right idea and enforce it galaxy-wide...
 * Another interesting twist from the setting are that humans are the Ancient Astronauts to other species. The Tau are one of the few species this happened to and who still exist; the ancient technology that the Tau found? A human ship that was supposed to wipe them out but was caught in a warpstorm.
 * Part of the Backstory of the Lizardmen in Warhammer Fantasy.
 * Used fairly often in D 20 Modern, especially the Dark* Matter setting.
 * In the Old World of Darkness, with absolutely no exaggeration, all of humanity's accomplishments were actually created by a vast Ancient Conspiracy of witches, vampires, werewolves, and other things that go bump in the night (except for WWII and 9/11, because the writers didn't want to offend the survivors). Humans never accomplished anything on their own, and are at best, sidekicks, and at worst, dogs.
 * Well, that was 1st Edition. In second edition this was dialed back a lot. Most of human history was done and dreamed up by humans, but then heavily influenced by the various supernaturals. It would have happened anyway, just differently. There were still exceptions though, two warring Vampire clans caused the Punic Wars, Werewolves probably wiped out the Ranoke colony and (probably the biggest one) Lucifer created Christianity. To help fight his former comrades. It's complicated.

Video Games

 * The Masari from Universe At War: Earth Assault is a homage to this trope -- an ancient alien species that inspired most of the ancient civilizations, and also the ancient Atlanteans. They went into stasis sleep eons ago before being awakened by the Earth being attacked by the Hierarchy.
 * Mass Effect has a few variants. There is a sidequest planet that tells you that that the ancient Protheans studied early humans, though there is no evidence that humanity actually worshiped them, and the only advancements in tech that humanity got from them were the high-tech ruins found on Mars. However, the hanar, a different alien race, do worship the Protheans, due to the fact that, according to their mythology, the Protheans taught them speech, and possibly made them sentient.
 * The Reapers do something similar
 * Mass Effect 3 reveals that the protheans took a very hands-on approach to
 * Also, Halo. While the Forerunners did interfere with humanity, that time came and went long before humanity kept records (about 100,000 years ago). The Covenant, on the other hand, embrace this trope to the point of Scary Dogmatic Aliens.
 * It was seemingly implied that Forerunners were actually humans, what with 343 Guilty Spark's belief in the first game that he had somehow already talked to the Master Chief in the prehistoric past and the fact that much of Forerunner technology could only be activated by humans, among many other things, but Halo Cryptum revealed that Forerunners were actually a separate species who were simply somewhat biologically related to humans. In fact, "prehistoric" humans(and their Prophet allies) had independently developed their own advanced interstellar empire, but ended up losing a war with the Forerunners. In the aftermath, humanity was stripped of its technology and forcibly devolved.
 * Guilty Spark's seemingly faulty memory might be due to the Forerunner geas (heritable genetic commands) placed on various human lineages, one of which apparently shares some relation with the Master Chief.
 * The Morrigi from the Sword of the Stars expansion, A Murder of Crows are several meter long "feathered serpents," the males of which have a "glamor" effect that makes them look like winged males of whatever species is seeing them. When viewed from space, the lights of their cities form giant glyphs, resembling the Nazca Lines and Crop Circles.
 * It should be noted that the Nazca lines translate to something like "For a good time, call..."
 * The Omega Stone Lampshades its own premise by including a cheesy "Aliens built Stonehenge!" paperback among the clues for the game's Glastonbury segment.
 * Technically, the D'ni people from the Myst games ought to qualify, although they wrote their way to Earth instead of landing here. Subverted in that the D'ni strictly avoided contact with natives of this planet for millennia, and only heretical renegades like Gehn had the gall to claim they were "gods" to inhabitants of other Ages.
 * In the Resistance series of PS 3/PSP games, it is revealed that
 * The alien entity Lavos, in Chrono Trigger and Chrono Cross is revealed to had caused the final evolution step of neanderthal-ish hominids into humans and be the chief influence in the raise of the most magically and technologically advanced civilizations of the world.
 * Although not set on Earth, the Might and Magic games.
 * Exactly how aware the inhabitants are of that varies from world to world. Enroth takes it to a point where it almost falls out of this trope.
 * Assassin's Creed II reveals
 * Inverted in Super Robot Wars Original Generation. Not only was all the super advanced Lost Technology on Earth created by Humans, but said Humans also spread to other planets in the distant past, handily explaining their liberal use of the Human Aliens trope.
 * Star Control has the Arilou Lalee'lay. They've been visiting earth since the dawn of man and have inspired the myths of gods, fairies, and apparently had something to do with the pyramids. Their main goal was crafting humans to be invisible to the Eldritch Abomination that ate the Androsynth. They act more like proud parents than anything else.
 * The Tales Series elves are aliens from a comet, of all things, called Derris-Kharlan, that is apparently a source of mana. And somehow these aliens are cross-fertile with humans.
 * The Cuotl in Rise of Legends are a Mayincatec civilization which has been subjugated by aliens posing themselves as gods, who have given the humans impressive technology (that cannot be told apart from magic).
 * In one of the earliest video gaming examples, the bird-like Chozo in the Metroid series have been roaming our galaxy for millennia, leaving behind ancient ruins and bits of their highly advanced technology everywhere. It just so happens that these bits of technology are quite useful to a certain armored, cave-exploring bounty hunter.[It helps that the armor of said armored action girl is also of Chozo creation]
 * Similar to the X-Files example above, in Iji,
 * The Kushan themselves were Ancient Astronauts in Homeworld, but they had forgotten their origins. They realize that they are not native to their planet when they rediscover the science of genetics and find that they are completely unrelated to any other form of life on the planet, while all other life is intimately related to each other.
 * In Doom 3,
 * Inverted in Asuras Wrath. Despite looking like they would be an ancient civilization, the Shinkoku Trastrium Race the game centers on is actually a culture of Future made to look like Ancient Hindu Mythology and Buddhism.

Web Comics

 * Reversed in Earthsong, where it's the people who make up the myths that have been traveling elsewhere, but have only faint memories of their alien companions once they snap back to their own place and time.
 * Inverted in The Inexplicable Adventures of Bob, in that the dragons of legend started out as a pre-human civilization here on Earth, then left for another planet, effectively becoming an alien race.
 * Played with in Minus. After reading about the theory, minus goes back in time to meet the aliens. She doesn't, but the effects of her visit leave a lot of seriously worried archaeologists.
 * Amazing Super Powers calls: reconcile your Hollywood Histories! Comes with a wink to Zechariah Sitchin (see below) teological... hmmm... exercises in Alt Text and a thematical hidden comic.
 * Bug translates the message of this trope as bluntly as they get.
 * Wayward Sons: The protagonists are the astronauts, crashed on our planet and empowered with a Healing Factor and Personality Powers. They become the Greek gods, while the antagonists become the Egyptian gods.
 * The seradin from Prophecy of the Circle are strongly hinted to be this, allegedly coming "from the stars" and leaving behind some high tech items, as well as a religion worshiping one of them.

Web Original

 * Land Games

Western Animation
"Fry: Yes! Insane theories: 1. Regular theories: a billion!"
 * Not always gods: In Transformers Cybertron, the monsters of earth's myths were actually Decepticons who came to Earth long ago, and were since sealed away by Crosswise... until Starscream freed them again.
 * This is also the Backstory of the Pretenders in Transformers Super God Masterforce. Things like the pyramids and Nazca lines were originally made to seal away the Decepticon Pretenders.
 * The characters of Transformers: Beast Wars
 * In the Gargoyles episode The Sentinel, it was revealed that the heads on Easter Island were actually busts of an alien lifeform whose military post was located there where he served as a sentry during a long ago war. The other mythical gods and monsters were based on terrestrial Gargoyles or The Fair Folk, not aliens.
 * Or on real monsters, apparently an offshoot of the Faerie now living in isolation.
 * The Real Adventures of Jonny Quest also has this explanation for the Easter Island heads, although it was more of an accident: An alien researcher was trapped on the island after its volcano erupted and lava engulfed its ship; the heads were used as a protective forcefield, if I recall correctly.
 * Futurama reversed this in "A Pharaoh to Remember," which introduces a planet bearing a remarkable resemblance to pharaonic Egypt, then explains that they copied everything--including culture and space travel--from the Ancient Egyptians.
 * As well as how to mummify their dead "so as to scare off Abbott and Costello."
 * Futurama reversed this in "A Pharaoh to Remember," which introduces a planet bearing a remarkable resemblance to pharaonic Egypt, then explains that they copied everything--including culture and space travel--from the Ancient Egyptians.
 * As well as how to mummify their dead "so as to scare off Abbott and Costello."


 * So is that an inversion, or is it a new trope? Astronaut Ancients, perhaps?
 * In another episode they played this trope straight, with the pyramids being built by Alien cats.
 * They did so to rob Earth of its rotational energy, which seems to be a play on a Real Life theory that pyramids are giant hydrogen engines used to power a microwave power station, which in turn powered star ships in orbit.
 * In Justice League Unlimited, two stranded Thanagarians become the architect for an ancient pre-Egyptian (per Word of God) culture.
 * Which is ironic considering the Thanagarians themselves had this relationship with a monster who taught them how to be civilized in exchange for human (well, Human Alien) sacrifice.
 * The cartoon Roswell Conspiracies: Aliens, Myths and Legends was all about how different kinds of alien had been living among humans from ancient times and were the origin of many of the human myths, folklore and legends (as the name implies...).
 * In the short stop-motion animation Prometheus and Bob, part of Nickelodeon's Ka Blam!, an alien called Prometheus descends to Earth in the early earthly pre-history and attempts to teach Bob, a neanderthal-esque caveman, basic technologies and civilized behavior, but failing every time with painful and hilarious consequences, either due the meddling of a cunning monkey or Bob's own slow wit. In the first episode, he's revealed to be the cause of the first humans losing their full-bodied ape-ish fur coat after an accident with a laser.
 * Star Trek the Animated Series episode "How Sharper Than A Serpent's Tooth". The alien being Kukulcan visited Earth in the distant past and was the basis for the Mayan god of the same name, the Toltec god Quetzalcoatl, and the Chinese dragons.

Other

 * Evoked hilariously in this clip of Conan O Brien and Tom Hanks when presented with a birthday present in this clip.
 * The idea was heavily popularized by Chariots Of The Gods, as mentioned above. The book was published in 1968 by Erich von Däniken, and quickly became a bestseller. It was copied lots of times, was made into at least two movies, and led to the Ancient Astronauts plot showing up in several of the examples here, such as Battlestar Galactica.
 * This trope parodied by this shirt from "Teach the Controversy."
 * One extremely popular variant of this trope is the claim that the ancient civilization of Atlantis consisted of expatriate aliens.
 * The absolute masterpiece of the early paranormal movement, the 1970s The Bermuda Triangle by Charles Berlitz, explores this angle. No sarcasm here: if you want to read about Alien Astronauts in the context of abandoned Atlantean technology causing planes to fall out of the sky, this is where you want to go.
 * There is a book by a certain Wolfgang Volkrodt suggesting that Daeniken is wrong - gods of old weren't aliens, only a secretive elite of technology users, awing the lesser people with "LOOK AT ME BALLOON I'M A GOD." The guy, being an engineer, even provides plans for their steam engines.
 * A similar theory states that the "highly technological ancient civilisation" wasn't aliens, only Atlanteans and possibly Lemurians, who blew themselves to smithereens long ago.
 * "Real life" example: David Icke's book The Biggest Secret is a conspiracy theory claiming that not only did reptilian aliens found the great ancient civilizations of Earth, they also continue to rule the Earth from the shadows.
 * ...and apparently don't mind the masses knowing that they rule secretly, since they allowed the publication of that book.
 * Or that their conspiracy received publicity due to a bizarre incident in the 2008 Minnesota US Senate race recount controversy.
 * Why should they? Everybody thinks that the people telling the thing are deluded retards, which just strengthens their conspiracy! It's not like anyone can now come forth with evidence without being laughed out of the room.
 * It's not like they'd be monitoring all Earth media, waiting to snatch authors away in the mid.
 * There's also a theory that the reptilian data is misinformation fed to Icke, in order to discredit him as he got too close to the real Illuminati.
 * You can find a carving of an astronaut on the New Cathedral of Salamanca, built in the 16th century.
 * Three thousand years later...
 * In a similar vein, the National Cathedral in Washington DC has, and I kid you not, a Darth Vader Grotesque. Stone By Day, Dark Lord of the Sith by Night...
 * The theory of panspermia/exogenesis posits that Earth's life has an extra-terrestrial origin.
 * Though, a good portion of those theories are less "extraterrestrials intentionally planted the seeds for life on Earth" and more "meteorites with the chemicals needed to develop life happened to smash into Earth from somewhere else in the universe."
 * Another "Real Life" example: Bible scholar Zechariah Sitchin firmly believes this to be fact. And his supposed source? The Bible itself. His works, The Earth Chronicles series, detail his studies and interpretations.
 * Also, for...some reason, Ke$ha in this clip
 * Scientology, anyone?
 * The Tale of the Bamboo Cutter from Japanese folklore is considered by many literary scholars to be the original Science Fiction story, with Princess Kaguya (who came from the moon) being an Ancient Astronaut.
 * The theory has been somewhat debunked regarding Stonehenge. A man working by himself is building a replica in his backyard using nothing but simple machines (mostly levers). At least he has proven that aliens didn't need to be involved.