According to ancient astronaut theories, intelligent extraterrestrial beings (called ancient astronauts or ancient aliens) have visited Earth and this contact is connected with the origins or development of human cultures, technologies, and/or religions.
Some of these theories propose that deities from most – if not all – religions are actually extraterrestrials, and their technologies were taken as evidence of their divine status.
These theories have been popularized, particularly in the latter half of the 20th century, by writers Erich von Däniken, Zecharia Sitchin, Robert K. G. Temple, and David Icke.
Ancient astronaut theories have been widely used in science fiction. Such theories have not received support within the scientific community, and have received little or no attention in peer reviewed studies from scientific journals.
Ancient astronaut adherents often claim that humans are either descendants or creations of beings who landed on Earth thousands of years ago. An associated theory is that much of human knowledge, religion, and culture came from extraterrestrial visitors in ancient times, in that ancient astronauts acted as a “mother culture”. These ideas are generally discounted by the scientific community.
Ancient astronaut theories also may include the idea that civilization may have evolved on Earth twice, and that the visitation of ancient astronauts may reflect the return of descendants of ancient humans whose population was separated from earthbound humans.
Proponents of ancient astronaut theories point to what they perceive as gaps in historical and archaeological records, and to what they see as absent or incomplete explanations of historical or archaeological data. They cite evidence that they argue supports their assertions, notably, archaeological artifacts that they argue are anachronistic or beyond the presumed technical capabilities of the historical cultures with which they are associated (sometimes referred to as "Out-of-place artifacts"); and artwork and legends which are interpreted as depicting extraterrestrial contact or technologies.
Scientists maintain that gaps in contemporary knowledge of the past do not demonstrate that such speculative ancient astronaut ideas are a necessary, or even plausible, conclusion to draw.The scientific community remains generally skeptical, and the dominant view is that there is no evidence to support ancient astronaut and paleocontact theories.
In their 1966 book Intelligent Life in the Universe astrophysicists I.S. Shklovski and Carl Sagan devote a chapter to arguments that scientists and historians should seriously consider the possibility that extraterrestrial contact occurred during recorded history. However, Shklovski and Sagan stressed that these ideas were speculative and unproven.
Shklovski and Sagan argued that sub-lightspeed interstellar travel by extraterrestrial life was a certainty when considering technologies that were established or feasible in the late '60s; that repeated instances of extraterrestrial visitation to Earth were plausible; and that pre-scientific narratives can offer a potentially reliable means of describing contact with outsiders. Additionally, Shklovski and Sagan cited tales of Oannes, a fishlike being attributed with teaching agriculture, mathematics, and the arts to early Sumerians, as deserving closer scrutiny as a possible instance of paleocontact due to its consistency and detail.
In his 1979 book Broca's Brain, Sagan suggested that he and Shklovski might have inspired the wave of '70s ancient astronaut books, expressing disapproval of "von Däniken and other uncritical writers" who seemingly built on these ideas not as guarded speculations but as "valid evidence of extraterrestrial contact." Sagan argued that while many legends, artifacts and purported out-of-place artifacts were cited in support of ancient astronaut theories, "very few require more than passing mention" and could be easily explained with more conventional theories. Sagan also reiterated his earlier conclusion that extraterrestrial visits to Earth were possible but unproven, and perhaps improbable.
Ancient astronaut theories can be found in the work of the following authors (listed by year of initial publication):
- 1897 – Garrett P. Serviss (book, Edison's Conquest of Mars)
* 1919 – Charles Fort
* 1928 – H.P. Lovecraft
* 1954 – Harold T. Wilkins
* 1955 – Morris K. Jessup
* 1957 – Peter Kolosimo (book, Il pianeta sconosciuto (The Unknown Planet))
* 1957 – George Hunt Williamson
* 1958 – Henri Lhote,
* 1959 – Matest M. Agrest
* 1959 – Jacques Bergier and Louis Pauwels (authors of The Morning of the Magicians)
* 1960 – Brinsley Le Poer Trench
* 1963 – Robert Charroux (book, One Hundred Thousand Years of Man's Unknown History)
* 1964 – W. Raymond Drake (book, Gods or Spacemen?)
* 1967 – Brad Steiger (book, The Flying Saucer Menace)
* 1968 – Erich von Däniken (book, Chariots of the Gods?)
* 1972 – Thomas Charles Lethbridge (book, The Legend of the Sons of God: A Fantasy?)
* 1974 – Charles Berlitz (book, The Bermuda Triangle)
* 1974 – Josef F. Blumrich (book, The Spaceships of Ezekiel)
* 1974 – Claude Vorilhon aka Rael (book, Le Livre Qui Dit La Vérité (The Book Which Tells the Truth))
* 1976 – Robert K. G. Temple
* 1978 – Zecharia Sitchin
* 1988 – Riley Martin
* 1993 – David Icke
* 1996 – Alan F. Alford
* 1996 – Richard C. Hoagland (book, The Monuments of Mars: A City on the Edge of Forever)
* 1998 – Lloyd Pye
* 1999 – Laurence Gardner (book, Genesis of the Grail Kings: The Explosive Story of Genetic Cloning)
* 2003 – Burak Eldem
- * 2018 - Aerik Vondenburg (book, The Secret Universe)
Other than the proponents' own interpretations of ancient writings and artifacts, there has yet to be found any hard evidence to support the ancient astronaut hypothesis.
Alan F. Alford, author of Gods of the New Millennium (1996), was an adherent of the ancient astronaut theory. Much of his work draws on Sitchin’s theories. However, he now finds fault with Sitchin’s theory after deeper analysis, stating that: “I am now firmly of the opinion that these gods personified the falling sky; in other words, the descent of the gods was a poetic rendition of the cataclysm myth which stood at the heart of ancient Near Eastern religions.”
A 2004 article in Skeptic Magazine states that von Däniken plagiarized many of the book's concepts from Le Matin des Magiciens, that this book in turn was heavily influenced by the Cthulhu Mythos, and that the core of the ancient astronaut theory originates in H. P. Lovecraft's short stories "The Call of Cthulhu" and "At the Mountains of Madness".