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. Etymology 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. 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), extraterrestrial anthropology, areoarchaeology and selenoarchaeology. Justification 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. 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. The study of alien cultures might offer us glimpses into our own species' past or future development. 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". 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