Executive producer of the series was
Kevin Burns from 2009 until 2021.
Giorgio Tsoukalos serves as consulting producer, and is a featured guest, appearing in every episode.
UFO researcher
C. Scott Littleton served as a producing consultant during the series development until his death in 2010.
Ancient Aliens originally aired a two-hour documentary
special for the
History Channel on March 8, 2009. The special was re-run several times, and is now packaged with the series as its pilot episode.
Ancient Aliens: The Series aired on History from 2010 to 2011, then moved to
H2 where it was promoted as one of the network's flagship series until 2014. Frequent re-airings of episodes continued on the History channel, with highlights and repackaged episodes airing on
A&E and
Lifetime. A selection of thirteen episodes which focused on the
2012 phenomenon was made available for syndication in the United States and Canada during the 2011–12 television season. In some foreign markets, the series still carries the
Ancient Aliens: The Series title card. In 2015, the series returned to History after H2 was relaunched as
Viceland. In response to complaints from disgruntled fans, Viceland created
Action Bronson Watches Ancient Aliens. History renewed
Ancient Aliens for a fifteenth season which premiered on January 24, 2020. Writer
David Childress, who appears in every episode, frequently concludes his comments with the exclamation, "—probably extraterrestrials!" Both Childress and Giorgio Tsoukalos repeatedly assert pre-historic peoples lacked the vocabulary to describe "technological" or "high-tech" devices (such as rockets or missiles, advanced weapons, aircraft, powered land vehicles, and medical instruments) that they allegedly witnessed, and thus referred to extraterrestrial visitors using such technology as gods. Terms such as "ancient astronauts", "ancient aliens", "alien visitors", "extra-terrestrial beings", "ancient gods", and "otherworldly beings", are used interchangeably by guests and the narration. Guests frequently conflate the meaning of "
theory" and "
hypothesis", or they frequently obscure or ignore the difference between
mythology and
legendary history, and verifiable
archaeology,
anthropology, or documented history.
Frequent guests In the first season, credentialed scientists and professionals, such as
Sara Seager and
Michael Denning, respond to claims made by other guests, but their rebuttals were not rigorous. In subsequent episodes, scientists and professionals offer explanations of scientific phenomena or historical events without endorsing claims made by other guests, or they offer personal commentary. Psychologist
Jonathan Young appears in 123 episodes, providing explanations of myths and legends, and legendary history. Boston University associate professor
Robert Schoch presents his
Sphinx water erosion hypothesis, as well as his hypothesis concerning the age and purpose of
Göbekli Tepe, in several episodes.
Erich von Däniken is the featured guest in the pilot episode, in addition to being the focus of two biographical episodes: "The Von Däniken Legacy", in Season 5, and "The Alien Phenomena", in Season 13. Radio talk show host
George Noory appears in more than 80 episodes, including the pilot episode. Reverend
Barry Downing, known for describing angels in the Bible as ancient astronauts, appears in the pilot episode, and his comments are repeated in later episodes. Writers
Robert Bauval and
Graham Hancock appear in many episodes. They both express skepticism of ancient astronauts, instead discussing their own theories of ancient civilizations. Hancock repeats the statement from his work that "There is a forgotten episode in human history."
Nick Pope and
Travis S. Taylor are also frequent guests. Segments and highlights from all first-season episodes, including the pilot, were edited into later episodes as late as Season 12, so that guests who appeared in Season 1 ostensibly appear in later seasons, although footage of their original interviews was re-used.
Evidence In many episodes, little empirical evidence is offered to support the presented claims. Episodes or episode segments focus on
out-of-place artifacts, such as: the
London Hammer,
Antikythera mechanism, or the Aiud object; or segments focus on alleged inconsistencies in the accepted
historical record. Guests discuss evidence which supports their claims in general or abstract terms. Some guests have alleged professionals and government officials have suppressed evidence of ancient mysteries, such as the in episode "The Prototypes" during which guests alleged that the
Smithsonian Institution suppressed findings of "giant humanoids" found alongside American Indian remains in the
Kanawha Valley. From Season 12 onward, some episodes have included segments in which evidence that potentially supports the ancient astronauts hypothesis is subjected to on-camera tests conducted by credentialed scientists and medical professionals. In the episode "The Science Wars", an
elongated skull was subject to an MRI examination, and DNA was extracted and tested. In the episode "The Star Gods of Sirius" blue, porous, nitrogen-rich stones, allegedly retrieved from the site of an alien visitation were examined by geologists. However, none of the results—from the skull, the stones, or other objects examined in later episodes—proved conclusive.
Other claims Other claims linked to the ancient astronauts hypothesis featured on the series include:
UFOs,
alien abductions, the
Roswell incident and
Rendlesham Forest incident,
panspermia, and
human space exploration. Guests have presented other pseudohistorical and pseudoscientific hypotheses related to, or dependent upon an understanding of:
Atlantis and other lost civilizations as described in works by
Brinsley Trench and
Edgar Cayce; or
ley lines as originally described by
Alfred Watkins, or more recent interpretations;
cataclysmic pole shifts as promoted by
Charles Hapgood; various forms of Christian and Hindu
creationism, or
pseudohistory and legendary history promoted followers of various
new religious movements; mythical and gnostic elements of the
Kabbalah,
Zohar, and
Book of Enoch. Other concepts explored include:
faith healing,
remote viewing, and various
psychic phenomena. Guests frequently discuss various forms of
catastrophism, and refer to other featured guests or historical figures as catastrophists. In several episodes, guests have claimed prominent historical figures were either influenced by or were possibly "extra-terrestrial" or "otherworldly beings." Guests have also discussed unrelated
pseudoscientific claims, such as:
dinosaurs coexisting with
humans until a recent
extinction event,
crystal healing and
crystal skulls, as well as
Freemasonry,
Rosicrucianism, and the
New World Order.
Linda Moulton Howe appears in several episodes which explore alien abduction, animal mutilation, and conspiracies involving alleged military installations on Antarctica. The 2013
Citizen Hearing on Disclosure features prominently in numerous episodes, such as Season 14's "The Nuclear Agenda". Prior to December 2012, several episodes explored aspects of the
2012 Mayan doomsday prophecy. The episodes "The Maya Conspiracy" and "The Doomsday Prophecies", which aired in February 2012, explored the
Maya calendar and its relation to the construction of
Palenque, the god
Kukulkan, in addition to links between the
Maya civilization and the ancient astronaut hypothesis. However, many featured artifacts, structures, and remains were actually
Aztec,
Zapotec, or
Olmec, and not Maya. Episodes focusing on
Mesoamerica broadcast after 2012 make no mention of the 2012 phenomenon. In the episode "The God Particle", guests linked the
Mayan long count to the discovery of the
Higgs boson. == Episodes ==