Extrasolar planets in fiction

{{Short description|none}} {{Redirect|Planets in science fiction|an overview of the Solar System's planets in fiction|Solar System in fiction}} {{Good article}} alt=Refer to caption|thumb|Artist's impression of a planet in a far-off system

Planets outside of the Solar System have appeared in fiction since at least the 1850s, long before the first real ones were discovered in the 1990s. Most of these fictional planets do not differ significantly from the Earth and serve only as settings for the narrative. The majority host native lifeforms, sometimes with humans integrated into the ecosystems. Fictional planets that are not Earth-like vary in many different ways. They may have significantly stronger or weaker gravity on their surfaces, or have a particularly hot or cold climate. Both desert planets and ocean planets appear, as do planets with unusual chemical conditions. Various peculiar planetary shapes have been depicted, including flattened, cubic, and toroidal. Some fictional planets exist in multiple-star systems where the orbital mechanics can lead to exotic day–night or seasonal cycles, while others do not orbit any star at all. More fancifully, planets are occasionally portrayed as having sentience, though this is less common than stars receiving the same treatment or a planet's lifeforms having a collective consciousness.

== General characteristics == {{Quote box | quote = [S]ince information about extrasolar planets remains limited and incomplete, science fiction writers can freely imagine various sorts of alien worlds where their heroes might experience different sorts of adventures and encounter exotic aliens. Indeed, one activity associated with hard science fiction is "world building", meticulously crafting bizarre planets that nonetheless accord with all scientific laws. | author = Gary Westfahl | source = ''Science Fiction Literature Through History: An Encyclopedia'' (2021), "Alien Worlds" entry<ref name="WestfahlAlienWorlds" /> | width = 475px }}

Most extrasolar planets in fiction are similar to Earth—referred to in the ''Star Trek'' franchise as Class M planets—and serve only as settings for the narrative.<ref name="WestfahlAlienWorlds" /><ref name="MillerImaginaryExoplanets" /> One reason for this, writes {{Interlanguage link|Stephen L. Gillett|qid=Q66665842}} in ''The Greenwood Encyclopedia of Science Fiction and Fantasy'', is to enable satire.<ref name="GreenwoodAlienWorlds" /> Nevertheless, there are also many fictional planets that differ significantly from Earth.<ref name="WestfahlAlienWorlds" /><ref name="MillerImaginaryExoplanets" /><ref name="GreenwoodAlienWorlds" /> Earth-like planets have become less common in fiction following the first detection of an exoplanet around a Sun-like star in 1995,{{Efn|Planets had already been found orbiting pulsars in 1992, but this is considered less significant and "1995 is widely accepted in the scientific community as the year exoplanets were discovered".<ref name="Puranen2024" />}} reflecting the scarcity of such worlds among the thousands discovered since.<ref name="Cooper2024">{{Cite web |last=Cooper |first=Keith |author-link= |date=2024-03-13 |title=As scientists find real exoplanets, sci-fi writers change their vision of alien worlds |url=https://www.space.com/science-fiction-exoplanets-reflect-real-discoveries |url-status=live |archive-url=https://web.archive.org/web/20240328194857/https://www.space.com/science-fiction-exoplanets-reflect-real-discoveries |archive-date=2024-03-28 |access-date=2024-04-23 |website=Space.com |language=en}}</ref><ref>{{Cite journal |last=Cartier |first=Kimberly M. S. |author-link= |date=2024-04-05 |title=Tatooine, Trisolaris, Thessia: Sci-Fi Exoplanets Reflect Real-Life Discoveries |url=http://eos.org/articles/tatooine-trisolaris-thessia-sci-fi-exoplanets-reflect-real-life-discoveries |url-status=live |archive-url=https://web.archive.org/web/20240411220517/http://eos.org/articles/tatooine-trisolaris-thessia-sci-fi-exoplanets-reflect-real-life-discoveries |archive-date=2024-04-11 |access-date=2024-04-23 |journal=Eos |volume=105 |language=en-US |doi=10.1029/2024eo240158|doi-access=free }}</ref> The majority of extrasolar planets in fiction are inhabited by native species,<ref name="Puranen2024" /> and humans are variously depicted as being integrated into or remaining apart from such alien ecosystems.<ref name="SFELifeOnOtherWorlds" /> Some fictional planets are described as orbiting real stars;<ref name="MillerImaginaryExoplanets">{{Cite web |last=Miller |first=Ron |author-link=Ron Miller (artist and author) |date=2011-11-18 |title=Imaginary Exoplanets |url=https://reactormag.com/imaginary-exoplanets/ |url-status=live |archive-url=https://web.archive.org/web/20240423114957/https://reactormag.com/imaginary-exoplanets/ |archive-date=2024-04-23 |access-date=2024-04-23 |website=Reactor |language=en-US}}</ref><ref name="WestfahlStars">{{Cite book |last=Westfahl |first=Gary |author-link=Gary Westfahl |title=Science Fiction Literature through History: An Encyclopedia |date=2021 |publisher=ABC-CLIO |isbn=978-1-4408-6617-3 |pages=602–604 |language=en |chapter=Stars |chapter-url=https://books.google.com/books?id=WETPEAAAQBAJ&pg=PA603}}</ref> a 2024 article in the ''Journal of Science Communication'' analysed a sample of 142 fictional exoplanets, of which nearly a third fulfilled this criterion, and found "an absence of influence of whether or not the planet setting is in a real star system on other worldbuilding characteristics".<ref name="Puranen2024">{{Cite journal |last1=Puranen |first1=Emma Johanna |last2=Finer |first2=Emily |last3=Helling |first3=Christiane |last4=Smith |first4=V. Anne |date=2024-03-04 |title=Science fiction media representations of exoplanets: portrayals of changing astronomical discoveries |url=https://jcom.sissa.it/article/pubid/JCOM_2301_2024_A04/ |journal=Journal of Science Communication |volume=23 |issue=1 |pages=A04 |doi=10.22323/2.23010204 |doi-access=free |issn=1824-2049|arxiv=2405.00684 }}</ref>

== Exotic shapes == Various exotic planetary shapes appear in fiction.<ref name="StanwayPeculiarPlanets" /> In Hal Clement's 1953 novel ''Mission of Gravity'', the planet Mesklin's rapid rotation causes it to be shaped roughly like a flat disk and gravity is consequently about 200 times weaker at the equator than it is at the poles,<ref name="WestfahlAlienWorlds" /><ref name="StanwayPeculiarPlanets" /><ref>{{Cite encyclopedia |year=2023 |title=Clement, Hal |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/clement_hal |access-date=2024-04-14 |author1-link=John Clute |editor1-last=Clute |editor1-first=John |edition=4th |author2-last=Langford |author2-first=David |author1-last=Clute |author1-first=John |author2-link=David Langford |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref> while the moon Jinx in Larry Niven's 1975 short story "The Borderland of Sol" is instead stretched by tidal forces from the planet it orbits rather than flattened, resulting in a prolate spheroid shape where the equator is covered by an atmosphere but the poles rise up above it.<ref name="May2023TidalForces">{{Cite book |last=May |first=Andrew |author-link= |title=How Space Physics Really Works: Lessons from Well-Constructed Science Fiction |publisher=Springer |year=2023 |isbn=978-3-031-33950-9 |series=Science and Fiction |pages=48–52 |language=en |chapter=Tidal Forces |doi=10.1007/978-3-031-33950-9_2 |chapter-url=https://books.google.com/books?id=zKXIEAAAQBAJ&pg=PA52}}</ref><ref name="VisualEncyclopediaExplorationAndColoniesTowardsTheStars" /> Another disk-shaped planet is the Discworld of Terry Pratchett's 1983–2015 fantasy book series of that name, a flat world which is carried on the backs of elephants that are in turn carried on the back of a turtle, with the arrangement orbited by the world's sun.<ref name="WestfahlAlienWorlds" /><ref>{{Cite encyclopedia |year=2015 |title=Discworld [series] |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/discworld_series |access-date=2021-11-29 |author1-link=David Langford |editor1-last=Clute |editor1-first=John |edition=4th |author1-last=Langford |author1-first=David |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref> Bizarro World in the ''Superman'' franchise is a cubic planet, rendered that shape by the actions of Superman.<ref name="WestfahlAlienWorlds" /><ref name="StanwayPeculiarPlanets">{{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2024-03-11 |title=Peculiar Planets |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/peculiar_planets |url-status=live |archive-url=https://web.archive.org/web/20240325001942/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/peculiar_planets |archive-date=2024-03-25 |access-date=2024-04-16 |website=Warwick University |series=Cosmic Stories Blog}}</ref> Earth itself gets turned into a cube in Henry H. Gross's 1987 short story "Cubeworld", and an altogether artificial planet-sized cube is the setting of G. David Nordley's 2009 novel ''To Climb a Flat Mountain''.<ref name="StanwayPeculiarPlanets" /> Double planets close enough together to share an atmosphere through their Roche lobes appear in Homer Eon Flint's 1921 short story "The Devolutionist", Robert L. Forward's 1982 novel ''Rocheworld'' ({{Aka}} ''The Flight of the Dragonfly''), Bob Shaw's 1986 novel ''The Ragged Astronauts''—which depicts an interplanetary hot air balloon expedition—and Charles Sheffield's 1990 novel ''Summertide''.<ref name="GreenwoodAlienWorlds">{{Cite book |last=Gillett |first=Stephen L. |title=The Greenwood Encyclopedia of Science Fiction and Fantasy: Themes, Works, and Wonders |date=2005 |publisher=Greenwood Publishing Group |isbn=978-0-313-32951-7 |editor-last=Westfahl |editor-first=Gary |editor-link=Gary Westfahl |pages=12–14 |language=en |chapter=Alien Worlds |chapter-url=https://archive.org/details/greenwoodencyclo0000unse_k2b9/page/12/mode/2up}}</ref><ref name="StanwayPeculiarPlanets" /><ref name="StablefordPlanet">{{Cite book |last=Stableford |first=Brian |author-link=Brian Stableford |title=Science Fact and Science Fiction: An Encyclopedia |date=2006 |publisher=Taylor & Francis |isbn=978-0-415-97460-8 |pages=374–376 |language=en |chapter=Planet |chapter-url=https://books.google.com/books?id=uefwmdROKTAC&pg=PA374}}</ref><ref name="TheZoneTheCircleCitadels" /> A planet in the shape of a torus is the setting of Flint's 1921 short story "The Emancipatrix", being the result of the protoplanetary disk condensing so quickly that it did not coalesce into a spherical shape first; an artificial planet-sized torus also appears in {{ill|John P. Boyd|qid=Q102276475}}'s 1981 short story "Moonbow", while Niven wrote of a much larger toroidal megastructure in space in the 1970 novel ''Ringworld'' and a much smaller one in the 1973 novel ''Protector''.<ref name="StanwayPeculiarPlanets" /> Arthur C. Clarke's 1949 short story "The Wall of Darkness" is set on a planet bounded by a wall in the shape of an Alice handle, a kind of three-dimensional equivalent of a Möbius strip.<ref name="WestfahlAlienWorlds" /><ref>{{Cite book |last=Westfahl |first=Gary |author-link=Gary Westfahl |url=https://books.google.com/books?id=5LlpswEACAAJ |title=Arthur C. Clarke |date=2018 |publisher=University of Illinois Press |isbn=978-0-252-04193-8 |series=Modern Masters of Science Fiction |location=Urbana |pages=95 |language=en |chapter=Alien Encounters}}</ref>

== In multiple star systems == [[File:Planets in binary star systems - P- and S-type.svg|alt=Refer to caption|thumb|Schematic diagram of the orbits in a binary star system. One planet is in a P-type, or circumbinary, orbit around both stars. Another planet is in an S-type, or circumstellar, orbit around only one of the two stars. Circumbinary planets are sometimes nicknamed "Tatooine worlds" after the ''Star Wars'' planet.<ref>{{multiref2|{{Cite web |last=Kaufman |first=Mark |date=2020-01-15 |title=Tatooine Worlds |url=https://astrobiology.nasa.gov/news/tatooine-worlds/ |url-status=live |archive-url=https://web.archive.org/web/20230811125933/https://astrobiology.nasa.gov/news/tatooine-worlds/ |archive-date=2023-08-11 |access-date=2021-12-03 |website=Astrobiology at NASA: Life in the Universe}}|{{Cite web |last=Sutter |first=Paul |author-link=Paul M. Sutter |date=2020-03-16 |title=How common are Tatooine worlds? |url=https://www.space.com/how-common-are-tatooine-alien-planets.html |url-status=live |archive-url=https://web.archive.org/web/20231208111858/https://www.space.com/how-common-are-tatooine-alien-planets.html |archive-date=2023-12-08 |access-date=2024-04-22 |website=Space.com |language=en}}|{{Cite web |last=Baker |first=Harry |author-link= |date=2023-06-13 |title=Astronomers discover 2nd-ever 'Tatooine' star system with multiple planets orbiting multiple suns |url=https://www.livescience.com/space/planets/astronomers-discover-2nd-ever-tatooine-star-system-with-multiple-planets-orbiting-multiple-suns |url-status=live |archive-url=https://web.archive.org/web/20231207171325/https://www.livescience.com/space/planets/astronomers-discover-2nd-ever-tatooine-star-system-with-multiple-planets-orbiting-multiple-suns |archive-date=2023-12-07 |access-date=2024-04-22 |website=Live Science |language=en}}}}</ref>]]

Planets in multiple star systems have attracted attention from science fiction writers, especially in terms of what kind of life would exist on planets with more than one sun and how history might be cyclical as a result of the "long year" that occurs if the orbital period around one of the stars is very lengthy.<ref name="StablefordPlanet" /><ref name="StanwayAllTheSunsInTheSky">{{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2021-09-19 |title=All the Suns in the Sky |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/all_the_suns |url-status=live |archive-url=https://web.archive.org/web/20230531040855/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/all_the_suns |archive-date=2023-05-31 |access-date=2024-04-20 |website=Warwick University |series=Cosmic Stories Blog}}</ref><ref name="SFEGreatYear" /> A particularly early example of this is C. I. Defontenay's 1854 novel ''Star ou Psi de Cassiopée'' (English title: ''Star: Psi Cassiopeia''),<ref name="StablefordPlanet" /> described by science fiction editor David Pringle as "the first detailed evocation of an alien solar system",<ref name="PringleSFInThe18thCentury">{{Cite book |title=The Ultimate Encyclopedia of Science Fiction: The Definitive Illustrated Guide |date=1996 |publisher=Carlton |isbn=1-85868-188-X |editor-last=Pringle |editor-first=David |editor-link=David Pringle |pages=16 |language=en |chapter=SF in the 18th Century |oclc=38373691 |chapter-url=https://archive.org/details/ultimateencyclop0000unse_a8c7/page/16/mode/2up}}</ref> which depicts various alien species inhabiting the planets orbiting the stars.<ref name="StablefordPlanet" /><ref name="MarcovitzAliensInPopCulture">{{Cite book |last=Marcovitz |first=Hal |title=Aliens in Pop Culture |date=2011 |publisher=Capstone |isbn=978-1-60152-365-5 |series=Extraterrestrial Life |pages=11–12 |language=en |chapter=Chapter One: The Aliens Arrive |chapter-url=https://books.google.com/books?id=4-fOCbkNSBwC&pg=PA12}}</ref><ref name="SFECIDefontenay">{{Cite encyclopedia |year=2022 |title=Defontenay, C I |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/defontenay_c_i |access-date=2024-04-15 |edition=4th |author1-last=Clute |author1-first=John |author1-link=John Clute |author2-last=Nicholls |author2-first=Peter |author2-link=Peter Nicholls (writer) |editor1-last=Clute |editor1-first=John |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref><ref name="AnatomyOfWonderStarPsiCassiopeia">{{Cite book |last=Stableford |first=Brian |author-link=Brian Stableford |title=Anatomy of Wonder: A Critical Guide to Science Fiction |date=2004 |publisher=Libraries unlimited |isbn=978-1-59158-171-0 |editor-last=Barron |editor-first=Neil |editor-link=Neil Barron |edition=5th |location=Westport, Connecticut |pages=179 |language=en |chapter=Star (Psi Cassiopeia) |quote=A pioneering account of life in the vicinity of Star, a world in a solar system that has three principal suns and a miniature sun that orbits Star along with four satellite planets. The multicolored light from these various sources has kaleidoscopic effects on the surface of Star, which is inhabited by variously sized humanoids whose history—involving forced migrations to its inhabited neighbors—is elaborately described. |orig-date=1976}}</ref> Isaac Asimov's 1941 short story "Nightfall" portrays a planet which is in constant daylight from at least one of its six suns for millennia at a time before a single night of true darkness, which is a much-anticipated event;<ref name="StanwayAllTheSunsInTheSky" /><ref name="GreenwoodStars">{{Cite book |last=McKinney |first=Richard L. |title=The Greenwood Encyclopedia of Science Fiction and Fantasy: Themes, Works, and Wonders |date=2005 |publisher=Greenwood Publishing Group |isbn=978-0-313-32952-4 |editor-last=Westfahl |editor-first=Gary |editor-link=Gary Westfahl |pages=751–753 |language=en |chapter=Stars |chapter-url=https://archive.org/details/greenwoodencyclo0002unse_f3t4/page/751/mode/2up}}</ref><ref>{{Cite encyclopedia |year=2024 |title=Asimov, Isaac |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/asimov_isaac |access-date=2024-04-14 |edition=4th |author1-last=Clute |author1-first=John |author1-link=John Clute |author2-last=Edwards |author2-first=Malcolm |author2-link=Malcolm Edwards |editor1-last=Clute |editor1-first=John |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref> the 1963 ''The Twilight Zone'' episode "On Thursday We Leave for Home" depicts a planet that is challenging for humans to inhabit due to the unending heat and light from a pair of suns;<ref name="BloomWeirdPlanets" /> and Mark Hodder's 2012 novel ''A Red Sun Also Rises'' is set on a planet where a dim red sun rises at the same time as the planet's twin white suns set.<ref name="StanwayAllTheSunsInTheSky" /> Hal Clement's 1957 novel ''Cycle of Fire'' depicts a planet in a binary star system where the seasons last for decades and different species dominate the hot and cold parts of the year,<ref name="WestfahlAlienWorlds" /><ref name="StablefordPlanet" /><ref name="SFEGreatYear" /> Poul Anderson's 1974 novel ''Fire Time'' portrays a planet where the majority of the surface becomes uninhabitable approximately once a millennium when it makes a close approach to one of its stars and mass migration of the native lifeforms ensues,<ref name="StanwayAllTheSunsInTheSky" /> and Brian Aldiss's 1982–1985 ''Helliconia'' trilogy is set on a planet where the orbital mechanics lead to century-long seasons and there are two distinct ecosystems—one adapted to the short period around the closer star and another adapted to the long year around the more distant one.<ref name="WestfahlAlienWorlds">{{Cite book |last=Westfahl |first=Gary |author-link=Gary Westfahl |title=Science Fiction Literature through History: An Encyclopedia |date=2021 |publisher=ABC-CLIO |isbn=978-1-4408-6617-3 |pages=107–110 |language=en |chapter=Alien Worlds |chapter-url=https://books.google.com/books?id=WETPEAAAQBAJ&pg=PA107}}</ref><ref name="GreenwoodAlienWorlds" /><ref name="StanwayAllTheSunsInTheSky" /><ref name="SFEGreatYear">{{Cite encyclopedia |year=2023 |title=Great Year |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/great_year |access-date=2024-04-14 |edition=4th |author1-last=Langford |author1-first=David |author1-link=David Langford |editor1-last=Clute |editor1-first=John |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref><ref>{{Cite encyclopedia |year=2024 |title=Aldiss, Brian W |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/aldiss_brian_w |access-date=2024-04-15 |edition=4th |author1-last=Clute |author1-first=John |author1-link=John Clute |author2-last=Pringle |author2-first=David |author2-link=David Pringle |editor1-last=Clute |editor1-first=John |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref> A similar effect appears in Aldiss's 1977 short story "Creatures of Apogee", albeit here as a result of a highly eccentric orbit around a single star where the distance to the star thus varies greatly between the nearest and farthest points in the orbit.<ref name="TheZoneTheCircleCitadels">{{Cite magazine |last=Bailey |first=K. V. |date=Winter 1997–1998 |editor-last=Lee |editor-first=Tony |editor-link= |title=The Circle Citadels: Other Solar Systems in Science Fiction |magazine=The Zone |pages=32–34 |issue=6 |issn=1351-5217}}</ref> The 1985 anthology ''Medea: Harlan's World'' is a collaborative effort between Harlan Ellison and several other science fiction writers consisting of several stories set on the same planet in a multiple star system.<ref name="WestfahlAlienWorlds" /><ref name="StablefordPlanet" /> The 2002 television series ''Firefly'' is set in a system of five stars each orbited by its own planetary system, all close enough to each other to permit easy travel between the worlds.<ref name="StanwayAllTheSunsInTheSky" />

== Rogue planets == {{See also|Fictional planets of the Solar System#Rogue planets}}

Planets that do not orbit any star, known as rogue planets, appear in several works.<ref name="StablefordPlanet" /><ref name="StanwayRoguePlanets">{{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2022-03-20 |title=Rogue Planets |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/rogue_planets |url-status=live |archive-url=https://web.archive.org/web/20230330111420/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/rogue_planets/ |archive-date=2023-03-30 |access-date=2024-04-23 |website=Warwick University |series=Cosmic Stories Blog}}</ref> In the 1977 novel ''Dying of the Light'' by George R. R. Martin, such a planet becomes a temporary tourist destination as it passes by a star before leaving the star's vicinity and becoming uninhabitable again.<ref name="StablefordPlanet" /><ref name="NicollFarFromAnyStar">{{Cite web |last=Nicoll |first=James Davis |author-link=James Nicoll |date=2020-04-30 |title=Far From Any Star: Five Stories About Rogue Worlds |url=https://reactormag.com/far-from-any-star-five-stories-about-rogue-worlds/ |url-status=live |archive-url=https://web.archive.org/web/20240416212524/https://reactormag.com/far-from-any-star-five-stories-about-rogue-worlds/ |archive-date=2024-04-16 |access-date=2024-04-23 |website=Reactor |language=en-US}}</ref> Hal Clement's 1974 short story "The Logical Life" explores what kind of life could exist on a planet without a star,<ref name="NicollFarFromAnyStar" /> while the 2002 ''Star Trek: Enterprise'' episode "Rogue Planet" depicts how the lifeforms on a world of perpetual night might be exploited by outsiders.<ref name="StanwayRoguePlanets" />

Earth is threatened by impact with a rogue planet in the 1933 novel ''When Worlds Collide'' by Edwin Balmer and Philip Wylie and its 1951 film adaptation,<ref name="StanwayRoguePlanets" /> and it becomes a rogue planet itself in Fritz Leiber's 1951 short story "A Pail of Air".<ref name="StanwayRoguePlanets" /><ref name="NicollFarFromAnyStar" /> A rogue planet on a collision course with a star-orbiting planet also appears in Neil R. Jones's 1934 short story "The Sunless World", though here the rogue planet is the inhabited one.<ref name="StablefordPlanet" /><ref>{{Cite book |last1=Bleiler |first1=Everett Franklin |author-link1=E. F. Bleiler |title=Science-fiction: The Gernsback Years : a Complete Coverage of the Genre Magazines ... from 1926 Through 1936 |last2=Bleiler |first2=Richard |author-link2=Richard Bleiler |date=1998 |publisher=Kent State University Press |isbn=978-0-87338-604-3 |pages=197 |language=en |chapter=Jones, Neil R[onald] (1908–1999) |chapter-url=https://books.google.com/books?id=PbMdeizaCNcC&pg=PA197}}</ref>

== Physical environment == [[File:Chlorineplanet.jpg|alt=Refer to caption|thumb|Artist's impression of a chlorine planet]]

Portraying planets with conditions that differ significantly from Earth's in terms of physical environment has been a recurring practice since the middle of the 1900s.<ref name="GreenwoodAlienWorlds" /> Many of these stories imagine how indigenous lifeforms might be adapted to those conditions, with Hal Clement and Poul Anderson being particularly prolific exponents of this craft.<ref name="SFELifeOnOtherWorlds">{{Cite encyclopedia |year=2023 |title=Life on Other Worlds |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/life_on_other_worlds |access-date=2024-04-15 |edition=4th |author1-last=Stableford |author1-first=Brian |author1-link=Brian Stableford |editor1-last=Clute |editor1-first=John |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref><ref name="VisualEncyclopediaExplorationAndColoniesTowardsTheStars">{{Cite book |title=The Visual Encyclopedia of Science Fiction |date=1977 |publisher=Harmony Books |isbn=0-517-53174-7 |editor-last=Ash |editor-first=Brian |editor-link=Brian Ash (bibliographer) |pages=87–88 |chapter=Exploration and Colonies: Towards the Stars |oclc=2984418 |chapter-url=https://archive.org/details/visualencycloped00ashb/page/87/mode/2up}}</ref><ref name="TheScienceInScienceFictionAlienAppearances">{{Cite book |last=Stableford |first=Brian |author-link=Brian Stableford |title=The Science in Science Fiction |date=1983 |publisher=Knopf |isbn=0-394-53010-1 |editor-last=Nicholls |editor-first=Peter |editor-link=Peter Nicholls (writer) |location=New York |pages=56–57 |chapter=Alien appearances |oclc=8689657 |chapter-url=https://archive.org/details/scienceinscience00nich/page/56/mode/2up}}</ref> The high gravity of Mesklin in Clement's ''Mission of Gravity'' thus results in its inhabitants having a centipede-like body structure,<ref name="WestfahlAlienWorlds" /><ref name="StanwayPeculiarPlanets" /><ref name="TheScienceInScienceFictionAlienAppearances" /><ref name="MammothPlanets">{{Cite book |last=Mann |first=George |author-link=George Mann (writer) |title=The Mammoth Encyclopedia of Science Fiction |date=2001 |publisher=Carroll & Graf Publishers |isbn=978-0-7867-0887-1 |pages=499 |language=en |chapter=Planets |chapter-url=https://archive.org/details/mammothencyclope00mann/page/499/mode/2up}}</ref> while the low gravity yet dense atmosphere in Anderson's 1958 novel ''War of the Wing-Men'' ({{Aka}} ''The Man Who Counts'') makes it possible for humanoid creatures to fly using their own wings.<ref name="WestfahlAlienWorlds" /><ref name="GreenwoodAlienWorlds" /><ref name="TheScienceInScienceFictionAlienAppearances" /> {{Anchor|Desert planets}}Desert planets are common; astrophysicist {{Interlanguage link|Elizabeth Stanway|qid=Q127710708}} posits that this is because the setting strikes the right balance between novelty and familiarity to most audiences, in addition to the relative inhospitality providing a survival aspect to the narrative.<ref name="StanwayDesertWorlds">{{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2023-01-01 |title=Desert Worlds |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/desert_worlds/ |url-status=live |archive-url=https://web.archive.org/web/20240325194809/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/desert_worlds/ |archive-date=2024-03-25 |access-date=2024-04-22 |website=Warwick University |series=Cosmic Stories Blog}}</ref> One of the most prominent examples thereof is Arrakis in Frank Herbert's 1965 novel ''Dune'', where the extreme scarcity of water influences all aspects of the planet's ecology and society.<ref name="WestfahlAlienWorlds" /><ref name="GreenwoodAlienWorlds" /><ref name="MammothPlanets" /><ref name="StanwayDesertWorlds" /><ref name="JohnstonExtremeWorlds">{{Cite web |last=Johnston |first=Michael |date=2017-07-24 |title=Five Books About Extreme Worlds |url=https://reactormag.com/five-books-about-extreme-worlds/ |url-status=live |archive-url=https://web.archive.org/web/20240416213806/https://reactormag.com/five-books-about-extreme-worlds/ |archive-date=2024-04-16 |access-date=2024-04-22 |website=Reactor |language=en-US}}</ref> Less extreme desert conditions are found on the ''Star Wars'' planet Tatooine, with more plentiful and varied lifeforms as a result.<ref name="StanwayDesertWorlds" /> At the other end of the spectrum are planets covered entirely by water, an early example of which appears in Neil R. Jones's 1933 short story "Into the Hydrosphere".<ref name="StablefordPlanet" /><ref name="TheScienceInScienceFictionAlienAppearances" /> Joan Slonczewski's 1986 novel ''A Door into Ocean'' is a piece of feminist science fiction set on an ocean world with an all-female population,<ref name="WestfahlAlienWorlds" /><ref name="GreenwoodAlienWorlds" /> while Ursula K. Le Guin's 1969 novel ''The Left Hand of Darkness'' is set on a frigid world of perpetual winter where the inhabitants do not have a fixed sex.<ref name="JohnstonExtremeWorlds" /><ref name="JensenParadiseNot">{{Cite web |last=Jensen |first=Kelly |date=2018-08-14 |title=Paradise Not: Five Inhospitable Planets |url=https://reactormag.com/paradise-not-five-inhospitable-planets/ |url-status=live |archive-url=https://web.archive.org/web/20240416213720/https://reactormag.com/paradise-not-five-inhospitable-planets/ |archive-date=2024-04-16 |access-date=2024-04-22 |website=Reactor |language=en-US}}</ref><ref name="CooperAmazingWorldsOfScienceFictionAndScienceFact">{{Cite web |last=Cooper |first=Keith |author-link= |date=2020-04-09 |title=Amazing Worlds of Science Fiction and Science Fact |url=https://reactormag.com/amazing-worlds-of-science-fiction-and-science-fact/ |url-status=live |archive-url=https://web.archive.org/web/20240423114906/https://reactormag.com/amazing-worlds-of-science-fiction-and-science-fact/ |archive-date=2024-04-23 |access-date=2024-04-23 |website=Reactor |language=en-US}}</ref> One of the planets in the 2014 film ''Interstellar'' is covered by a shallow ocean and orbits so closely around a black hole that there are both tidal waves the height of mountains and extreme time dilation.<ref name="JensenParadiseNot" /> Other fictional planets differ in their chemical rather than physical environment. Chlorine planets appear in Isaac Asimov's 1951 short story "C-Chute" and the 1976 ''Space: 1999'' episode "The AB Chrysalis",<ref name="BloomWeirdPlanets">{{Cite book |last=Bloom |first=Steven D. |title=The Physics and Astronomy of Science Fiction: Understanding Interstellar Travel, Teleportation, Time Travel, Alien Life and Other Genre Fixtures |date=2016 |publisher=McFarland |isbn=978-0-7864-7053-2 |pages=55–57 |language=en |chapter=Weird Planets |chapter-url=https://books.google.com/books?id=8NbIDAAAQBAJ&pg=PA55}}</ref> while C. J. Cherryh's 1988 novel ''Cyteen'' depicts a planet dominated by silicon-based life whose biochemistry creates byproducts extremely hazardous to human health.<ref name="NicollTrulyInhospitableFictionalPlanets">{{Cite web |last=Nicoll |first=James Davis |author-link=James Nicoll |date=2020-05-08 |title=Five Truly Inhospitable Fictional Planets |url=https://reactormag.com/five-truly-inhospitable-fictional-planets/ |url-status=live |archive-url=https://web.archive.org/web/20240423123819/https://reactormag.com/five-truly-inhospitable-fictional-planets/ |archive-date=2024-04-23 |access-date=2024-07-18 |website=Reactor |language=en-US}}</ref>

== Living == {{See also|Stars in fiction#Sentient|Sun in fiction#Sentient|Black holes in fiction#Sentient}}

{{Anchor|Sentient}} Planets themselves being portrayed as alive, while relatively rare (especially compared to stars receiving the same treatment), is a recurring theme.<ref name="WestfahlAlienWorlds" /><ref name="SFELivingWorlds" /> Sentient planets appear in Ray Bradbury's 1951 short story "Here There Be Tygers", Stanisław Lem's 1961 novel ''Solaris'', and Terry Pratchett's 1976 novel ''The Dark Side of the Sun''.<ref name="WestfahlAlienWorlds" /><ref name="SFELivingWorlds">{{Cite encyclopedia |year=2022 |title=Living Worlds |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/living_worlds |access-date=2024-04-14 |edition=4th |author1-last=Stableford |author1-first=Brian |author1-link=Brian Stableford |author2-last=Langford |author2-first=David |author2-link=David Langford |editor1-last=Clute |editor1-first=John |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref> Ego the Living Planet is a recurring character in Marvel Comics.<ref name="SFELivingWorlds" /> The related concept known as the Gaia hypothesis—an entire planetary ecosphere functioning as a single organism, often but not always imbued with a planet-wide consciousness—is more common; examples include Murray Leinster's 1949 short story "The Lonely Planet", Isaac Asimov's 1982 novel ''Foundation's Edge'', and the 2009 film ''Avatar''.<ref name="SFELivingWorlds" /><ref>{{Cite encyclopedia |year=2018 |title=Gaia |encyclopedia=The Encyclopedia of Science Fiction |url=https://sf-encyclopedia.com/entry/gaia |access-date=2021-12-04 |edition=4th |author1-last=Langford |author1-first=David |author1-link=David Langford |editor1-last=Clute |editor1-first=John |editor1-link=John Clute |editor2-last=Langford |editor2-first=David |editor2-link=David Langford |editor3-last=Sleight |editor3-first=Graham |editor3-link=Graham Sleight}}</ref><ref name="BloomIntelligentPlanets">{{Cite book |last=Bloom |first=Steven D. |title=The Physics and Astronomy of Science Fiction: Understanding Interstellar Travel, Teleportation, Time Travel, Alien Life and Other Genre Fixtures |date=2016 |publisher=McFarland |isbn=978-0-7864-7053-2 |pages=198–199 |language=en |chapter=Intelligent Planets |chapter-url=https://books.google.com/books?id=8NbIDAAAQBAJ&pg=PA198}}</ref>

== List == The following are fictional extrasolar planets with stand-alone Wikipedia articles.

{| class="wikitable sortable" !Planet !Source |- |Abeir-Toril |''Dungeons & Dragons'' |- |Alderaan |''Star Wars'' |- |Apokolips |''DC Comics'' |- |Arrakis |''Dune'' |- |Bizarro World |''DC Comics'' |- |Coruscant |''Star Wars'' |- |Dagobah |''Star Wars'' |- |Discworld |''Discworld'' |- |Ego the Living Planet |''Marvel Comics'' |- |Hoth |''Star Wars'' |- |The Known World |''A Song of Ice and Fire'' |- |Krypton |''Superman'' |- |Mesklin |''Mission of Gravity'' |- |Mogo |''DC Comics'' |- |Mongo |''Flash Gordon'' |- |Mystara |''Dungeons & Dragons'' |- |Riverworld |''To Your Scattered Bodies Go'' |- |Tatooine |''Star Wars'' |}

==See also== <imagemap> File:Solar system.jpg|alt=A photomontage of the eight planets and the Moon|thumb|Clicking on a planet leads to the article about its depiction in fiction. circle 1250 4700 650 Neptune in fiction circle 2150 4505 525 Uranus in fiction circle 2890 3960 610 Saturn in fiction circle 3450 2880 790 Jupiter in fiction circle 3015 1770 460 Mars in fiction circle 2370 1150 520 Earth in science fiction circle 3165 590 280 Moon in science fiction circle 1570 785 475 Venus in fiction circle 990 530 320 Mercury in fiction </imagemap> * Fictional planets of the Solar System * List of ''Star Wars'' planets and moons * Solar System in fiction * Stars in fiction * {{Annotated link|Tralfamadore}} {{Clear}}

==Notes== {{Notelist}}

==References== {{Reflist|30em}}

== Further reading == * {{Cite web |last=Fraknoi |first=Andrew |author-link=Andrew Fraknoi |date=January 2024 |title=Science Fiction Stories with Good Astronomy & Physics: A Topical Index |url=https://astrosociety.org/file_download/inline/7b5edc23-7a89-46c1-a6b3-33a30ed4c876 |url-status=live |archive-url=https://web.archive.org/web/20240210011957/https://astrosociety.org/file_download/inline/7b5edc23-7a89-46c1-a6b3-33a30ed4c876 |archive-date=2024-02-10 |archive-format=PDF |access-date=2024-04-15 |publisher=Astronomical Society of the Pacific |pages=6 |format=PDF |edition=7.3}} * {{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2025-05-18 |title=Scarlet Skies |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/scarlet_skies |url-status=live |archive-url=https://web.archive.org/web/20250518130229/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/scarlet_skies |archive-date=2025-05-18 |access-date=2025-05-18 |website=Warwick University |series=Cosmic Stories Blog}} * {{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2025-10-19 |title=Habitable Exomoons |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/habitable_exomoons |url-status=live |archive-url=https://web.archive.org/web/20251019153740/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/habitable_exomoons |archive-date=2025-10-19 |access-date=2025-10-19 |website=Warwick University |series=Cosmic Stories Blog}} * {{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2025-12-14 |title=Out of this World Holidays |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/out_of_this/ |url-status=live |archive-url=https://web.archive.org/web/20251214135956/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/out_of_this/ |archive-date=2025-12-14 |access-date=2025-12-14 |website=Warwick University |series=Cosmic Stories Blog}} * {{Cite web |last=Stanway |first=Elizabeth |author-link= |date=2026-01-25 |title=Strange New Worlds |url=https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/strange_new_worlds/ |url-status=live |archive-url=https://web.archive.org/web/20260125232451/https://warwick.ac.uk/fac/sci/physics/research/astro/people/stanway/sciencefiction/cosmicstories/strange_new_worlds/ |archive-date=2026-01-25 |access-date=2026-01-25 |website=Warwick University |series=Cosmic Stories Blog}}

Category:Fiction about planets