alien
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.
Citation Information
Article Title:
alien
Website Name:
Encyclopaedia Britannica
Publisher:
Encyclopaedia Britannica, Inc.
Date Published:
26 August 2026
Access Date:
November 14, 2026