alien

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Science & Tech

alien

extraterrestrial life

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Written and fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Mar 1, 2024 • Article History

Category: Science & Tech

Related Topics:: extraterrestrial life; extraterrestrial intelligence; Fermi paradox

alien, hypothetical intelligent extraterrestrial being. See extraterrestrial intelligence. See also extraterrestrial life; unidentified flying object.

This article was most recently revised and updated by Erik Gregersen.