Xenoarchaeology, a branch of xenology dealing with extraterrestrial cultures, is a hypothetical form of archaeology that exists mainly in works of science fiction. The field is concerned with the study of the material remains to reconstruct and interpret past life-ways of alien civilizations. Xenoarchaeology is not currently practiced by mainstream archaeologists due to the current lack of any material for the discipline to study.


The name derives from Greek xenos (ξένος) which means 'stranger, alien', and archaeology 'study of ancients'.

Xenoarchaeology is sometimes called astroarchaeology or exoarchaeology, although some would argue that the prefix exo- would be more correctly applied to the study of human activities in a space environment.[1]

Other names for xenoarchaeology, or specialised fields of interest, include Probe SETI (Search for Extra-Terrestrial Intelligence), extraterrestrial archaeology, space archaeology, SETA (Search for Extra-Terrestrial Artifacts), Dysonian SETI, Planetary SETI, SETT (Search for Extra-Terrestrial Technology), SETV (Search for Extra-Terrestrial Visitation),[2] extraterrestrial anthropology, areoarchaeology and selenoarchaeology.[3]


It is arguably the case that, due to the immense distances between stars, any evidence we discover of extraterrestrial intelligence, whether it be an artifact or an electromagnetic signal, may come from a long-vanished civilization. Thus the entire SETI project can be seen as a form of archaeology.[4][5][6] Additionally, due to the extreme age of the universe, there may be a reasonable expectation for astrobiology research to produce evidence of extinct alien life prior to the discovery of alien life itself.[7]

The study of alien cultures might offer us glimpses into our own species' past or future development.[8][9]

Vicky Walsh argued for the existence of "exo-artifacts" using the principle of mediocrity and the Drake equation. She proposed that a theoretical and speculative field of archaeology be established in order to test outlandish claims and to prepare for a time when undeniably extraterrestrial artifacts needed to be analysed. "If it is possible to construct an abstract archaeology that can be tested and refined on earth and then applied to areas beyond our planet, then the claims for ETI remains on the moon and Mars may really be evaluated in light of established archaeological theory and analysis".[10]

Ben McGee similarly proposed the creation of a set of interdisciplinary, proactive xenoarchaeological guidelines, arguing that identifying suspected artifacts of astrobiology is all that is required to justify establishing a methodology for xenoarchaeology. He emphasized the necessity of proactive xenoarchaeological work in order to avoid future bias, mischaracterization, and information mismanagement, and he cites three scenarios under which such a methodology or set of guidelines would be useful, those being "remote sensing" of a potential xenoarchaeological artifact, encountering an artifact during "human exploration," and "terrestrial interception" of an artifact.[7]

Greg Fewer has argued that archaeological techniques should be used to evaluate alleged UFO landing or crash sites, such as Roswell.[11]


The origins of the field have been traced[12] to theories about a hypothetical Martian civilization based on observations of what were perceived as canals on Mars. These theories, of which Percival Lowell was the most famous exponent, were apparently inspired by a mistranslation of a quote by Giovanni Schiaparelli.

The 1997 Theoretical Archaeology Group conference featured a session on "archaeology and science fiction".[13]

The 2004 annual meeting of the American Anthropological Association featured a session Anthropology, Archaeology and Interstellar Communication.[14]

Planetary SETI

Planetary SETI is concerned with the search for extraterrestrial structures on the surface of bodies in the Solar System. Claims for evidence of extraterrestrial artifacts can be divided into three groups, the Moon, Mars, and the other planets and their satellites.[3]

Examples of sites of interest include the "bridge" sighted in the Mare Crisium in 1953, and the "Blair Cuspids", "an unusual arrangement of seven spirelike objects of varying heights" at the western edge of the Mare Tranquillitatis, photographed by the Lunar Orbiter 2 on 20 November 1966.[15] In 2006, Ian Crawford proposed that a search for alien artifacts be conducted on the Moon.[16]

Percival Lowell's mistaken identification of Martian canals[17] was an early attempt to detect and study an alien culture from its supposed physical remains.[citation needed] More recently, there was interest in the supposed Face on Mars, an example of the psychological phenomenon of pareidolia.[18]

The Society for Planetary SETI Research is a loose organization of researchers interested in this field. The organization does not endorse any particular conclusions drawn by its members on particular sites.[19]

Probe SETI, or SETA

Further information: Bracewell probe

A great deal of research and writing has been done, and some searches conducted for extraterrestrial probes in the Solar System.[20] This followed the work of Ronald N. Bracewell.

Robert Freitas,[21][22][23] Christopher Rose and Gregory Wright have argued that interstellar probes can be a more energy-efficient means of communication than electromagnetic broadcasts.[24]

If so, a solar centric Search for Extraterrestrial Artifacts (SETA)[25] would seem to be favored over the more traditional radio or optical searches. Robert A. Freitas coined the term SETA in the 1980s.[26]

On the basis that the Earth-Moon or Sun-Earth libration orbits might constitute convenient parking places for automated extraterrestrial probes, unsuccessful searches were conducted by Freitas and Valdes.[27][28]

Dysonian SETI

In a 1960 paper, Freeman Dyson proposed the idea of a Dyson sphere, a type of extraterrestrial artifact able to be searched for and studied at interstellar distances. Following that paper, several searches have been conducted.[29]

In a 2005 paper, Luc Arnold proposed a means of detecting smaller, though still mega-scale, artifacts from their distinctive transit light curve signature.[30] (see Astroengineering).

Fringe theories

A subculture of enthusiasts studies purported structures on the Moon or Mars. These controversial "structures" (such as the Face on Mars) are not accepted as more than natural features by most scientists, examples of the pareidolia phenomenon.

Palaeocontact or ancient astronaut theories, espoused by Erich von Däniken and others, are further examples of fringe theories. These claim that the Earth was visited in prehistoric times by extraterrestrial beings.

Science fiction

This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2020) (Learn how and when to remove this template message)

Xenoarchaeological themes are common in science fiction. Works about the exploration of enigmatic extraterrestrial artifacts have been satirically categorized as Big Dumb Object stories.

Some of the more prominent examples of xenoarchaeological fiction include Arthur C. Clarke's novel Rendezvous with Rama, H. Beam Piper's short story Omnilingual, and Charles Sheffield's Heritage Universe series.


Short stories

Video games



See also


  1. ^ Freitas, Robert. "Naming Extraterrestrial Life"., retrieved 7 October 2006.
  2. ^ Darling, David. "SETA (Search for Extraterrestrial Artifacts)"., retrieved 7 October 2006.
  3. ^ a b Matthews, Keith, 2002, Archaeology and the Extraterrestrial, in Miles Russell (ed), Digging Holes in Popular Culture, Bournemouth University School of Conservation Sciences Occasional Paper 7, Oxbow Books, Oxford, pp. 129–60
  4. ^ "They're Dead, Jim!". SETI League. Retrieved 7 October 2006.
  5. ^ "Future Archaeology". Astrobiology Magazine. 5 October 2006. Archived from the original on 29 September 2007.((cite web)): CS1 maint: unfit URL (link)
  6. ^ Tarter, Jill (9 July 2004). "Communication with Extraterrestrial Intelligence – A Necessarily Long-Term Strategy". Archived from the original on 13 August 2006. Retrieved 7 October 2006.
  7. ^ a b McGee, Ben (November 2010). "A Call for Proactive Xenoarchaeological Guidelines: Scientific, International Policy, and Socio-Political Considerations". Space Policy. 26 (4): 209. doi:10.1016/j.spacepol.2010.08.003.
  8. ^ Thomas, Charles (February 1996). "Diggers at the final frontier". British Archaeology (11). Archived from the original on 16 July 2012. Retrieved 7 October 2006.
  9. ^ Kershaw, Carolyne (June 1996). "Letters – Star Trek digging". British Archaeology (15). Archived from the original on 19 July 2012. Retrieved 7 October 2006.
  10. ^ Walsh, Vicky, 2002, The case for exo-archaeology, in Miles Russell (ed), Digging Holes in Popular Culture, Bournemouth University School of Conservation Sciences Occasional Paper 7, Oxbow Books, Oxford, pp. 121–8.
  11. ^ Fewer, Greg. "Searching for extraterrestrial intelligence: an archaeological approach to verifying evidence for extraterrestrial exploration on Earth" (PDF). Archived from the original (PDF) on 27 September 2007. Retrieved 7 October 2006.
  12. ^ Sutton, Mark Q. & Yohe, Robert M., II 2003, Archaeology: The Science of the Human Past, Allyn & Bacon, Boston, p. 73
  13. ^ "'When Worlds Collide': Archeology and Science Fiction". Theoretical Archeology Group Annual Conference 1997: Programme (PDF). 1997. p. 8. Retrieved 5 March 2020.
  14. ^ http://www.seti.org/site/pp.asp?c=ktJ2J9MMIsE&b=617353,[dead link] retrieved 7 October 2006.
  15. ^ Louis Proud, The Secret Influence of the Moon: Alien Origins and Occult Powers (Inner Traditions / Bear & Co, 2013)
  16. ^ Groshong, Kimm (16 May 2006). "Looking for aliens on the Moon". New Scientist. Retrieved 7 October 2006.
  17. ^ Dunlap, David W. (1 October 2015). "Life on Mars? You Read It Here First". The New York Times. Retrieved 1 October 2015.
  18. ^ Britt, Robert Roy (18 March 2004). "Scientist attacks alien claims on Mars". CNN. SPACE.com. Retrieved 12 October 2007.
  19. ^ "Society for Planetary SETI Research". Archived from the original on 14 January 2009. Retrieved 5 October 2006.
  20. ^ Stride, Scot (February 2001). "Probing for ETI's Probes in the Solar System". The SETI League. Retrieved 7 October 2006.
  21. ^ Freitas Jr., Robert A. (1980). "Interstellar Probes: a New Approach to SETI". Journal of the British Interplanetary Society. 33: 95–100. Retrieved 7 October 2006.
  22. ^ Freitas Jr., Robert A. (July–August 1983). "Debunking the Myths of Interstellar Probes". AstroSearch. pp. 8–9. Retrieved 7 October 2006.
  23. ^ Freitas Jr., Robert A. (November 1983). "The Case for Interstellar Probes". Journal of the British Interplanetary Society. 36: 490–495. Retrieved 7 October 2006.
  24. ^ Rose, Christopher; Wright, Gregory (2 September 2004). "Inscribed Matter as an Energy-Efficient Means of Communication with an Extraterrestrial Civilization" (PDF). Letters to Nature. Nature. 431 (7004): 47–49. doi:10.1038/nature02884. Retrieved 7 October 2006.
  25. ^ Freitas Jr., Robert A. (1983). "The Search for Extraterrestrial Artifacts (SETA)". Journal of the British Interplanetary Society. 36: 501–506. Retrieved 7 October 2006.
  26. ^ Csaba Kecskes: Observation of Asteroids for Searching Extraterrestrial Artifacts. in: Viorel Badescu: Asteroids - prospective energy and material resources. Springer, Berlin 2013, page 635. ISBN 978-3-642-39243-6.
  27. ^ Freitas Jr., Robert A.; Valdes, Francisco (1980). "A Search for Natural or Artificial Objects Located at the Earth-Moon Libration Points". Icarus. 42: 442–447. Retrieved 7 October 2006.
  28. ^ Valdes, Francisco; Freitas Jr., Robert A. (1983). "A Search for Objects near the Earth-Moon Lagrangian Points". Icarus. 53: 453–457. Retrieved 7 October 2006.
  29. ^ Carrigan, D., Other Dyson Sphere searches Archived 16 July 2012 at the Wayback Machine, retrieved 7 October 2006.
  30. ^ Arnold, Luc (March 2005). "Transit Lightcurve Signatures of Artificial Objects". The Astrophysical Journal. 627 (1): 534–539. arXiv:astro-ph/0503580. Bibcode:2005ApJ...627..534A. doi:10.1086/430437. S2CID 15396488.