Exolinguistics (also called xenolinguistics and astrolinguistics) is the hypothetical (and fictional) study of the language of alien species. The nature and form of such languages remains purely speculative because so far no search for extra-terrestrial intelligence projects have detected signs of intelligent life beyond Earth. The possibility of future contact with intelligent extra-terrestrial life has made the question of the structure and form of potential alien language a topic of scientific and philosophical discussion.