Extraterrestrials in fiction
Extraterrestrials in fiction are lifeforms that did not originate on Earth. The idea of aliens has been around since ancient stories, but the way writers pictured them changed a lot over time.
Early ideas often made aliens look and act like humans. After Charles Darwin introduced evolution, authors began imagining truly alien beings that could be very different from people. Some of the first to push these ideas were Camille Flammarion, who described strange sentient life, and H. G. Wells, who gave us nonhuman invaders in The War of the Worlds and the sun-powered Selenites in The First Men in the Moon. In Stanley G. Weinbaum’s A Martian Odyssey, aliens had a real, strange ecosystem of their own.
Pulp magazines in the early 20th century popularized space adventures with clear good guys and clear monsters. Aliens from the Solar System—Martians, Venusians, Jovians—often appeared, sometimes humanoid and sometimes not. In these stories, invasions were a common theme and the aliens could be anywhere from terrifying to helpful.
A notable non-American influence is The Eternaut, a 1960s Argentine comic that shows an alien invasion of Buenos Aires and uses the story to critique imperialism and dictatorship. It introduces several kinds of aliens and shows how different groups might respond to an outside threat.
In the 1950s and 60s, the abduction idea entered popular culture, with the Barney and Betty Hill case helping to popularize the image of the gray alien—big head, large eyes, pale skin. This image influenced many later films and TV shows. Steven Spielberg’s Close Encounters of the Third Kind and E.T. the Extra-Terrestrial helped make aliens memorable characters rather than just scary invaders.
With TV and movies, actors in costumes became common, so many aliens looked human with a few unusual features. Star Trek and Star Wars became huge franchises, shaping how stories about aliens were told. Later, computer-generated imagery (CGI) in the 1990s and beyond allowed filmmakers to create truly bizarre and wonderful lifeforms without needing actors in costumes.
Today, extraterrestrials in fiction can be more or less intelligent than humans, and their biology can be humanoid, animal-like, or completely alien. They can be hostile invaders, friendly teachers or allies, victims of humans, or just observers of humanity. Some aliens come from other worlds, but others come from Earth in places we don’t usually see—under the sea, in the sky, underground, or even in other dimensions or alternate histories. Many stories mix science with imagination to explore what life might be like beyond Earth.
This page was last edited on 2 February 2026, at 08:12 (CET).