![]() Martian controlled Tripod, from H. G. Wells's 1898 novel The War of the Worlds | |
Grouping | Science fiction |
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Similar entities | Cryptids |
Other name(s) | Aliens, space aliens |
An extraterrestrial or alien is a lifeform that did not originate on Earth. The word extraterrestrial means 'outside Earth'. Extraterrestrials are a common theme in modern science-fiction, and also appeared in much earlier works such as the second-century parody True History[1] by Lucian of Samosata.[2]