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 October 2024
URL: https://www.britannica.comhttps://www.britannica.com/science/alien-extraterrestrial-life
Access Date: November 21, 2024