Phobos and Deimos
Entry updated 7 September 2026. Tagged: Theme.
The two moons of Mars, whose Greek mythological names respectively mean fear or panic and terror or dread. Their existence was famously predicted in Jonathan Swift's Gulliver's Travels (1726; rev 1735), and they were mentioned in Voltaire's "Micromegas" (contained in Le Micromégas de Mr. de Voltaire, avec une Histoire des Croisades & un nouveau plan de l'Histoire de l'esprit humain [coll 1752; trans Tobias Smollett as Micromegas, a Comic Romance 1753]). Also in the eighteenth century, Eberhard Christian Kindermann's Die Geschwinde Reise auf dem Lufft-Schiff nach der Obern Welt, welche jüngsthin fünff Personen angestellet ["The Speedy Journey by Airship to the Upper World, Recently Taken by Five People"] (1744; trans Dwight R Decker as The Speedy Journey 2014) described the discovery of a fictitious Martian moon. However, the actual moons were not discovered until 1877 because they are, in comparison with Earth's Moon, very tiny. each less than 10 miles in diameter. They appear in sf with surprising frequency, though not always as the centre of attention. Stories consider the moons either as objects or as settings: as objects, they are destroyed, transformed, moved, or revealed to be alien constructs; as settings, they are sometimes improbably portrayed as habitable with Alien life, or are more realistically described as barren and airless.
Perhaps the first story about the destruction of a Martian moon is George C Wallis's "The Great Sacrifice: A Scientific Romance" (June 1903 The London Magazine), describing a devastating Meteor storm that destroys Phobos. Aliens cause the moons to crash into each other and fall to Mars's surface in A L Burkholder's "The Mad World" (February 1935 Wonder Stories). In J Lewis Burtt's "The Martian Mail" (April 1935 Amazing Stories), a malfunctioning device causes Earth and Mars to leave their orbits, resulting in Deimos crashing into the Moon. Deimos is deliberately destroyed because of its dangerous inhabitants in D L James's "The Crystal of Madness" (October 1936 Thrilling Wonder Stories). In the Comic strip Spacehawk, a disgruntled politician makes Phobos collide with Mars, and in Kim Stanley Robinson's Red Mars (1992) Phobos as well as Mars is colonized, but conflicts lead to it being smashed into Mars.
One notable story about a dramatically transformed moon is Arthur C Clarke's Sands of Mars (1952), in which Phobos is somehow transformed into a second sun to warm the planet. In a similar story in Tit-Bits Science Fiction Comics, the discovery of uranium on Deimos allows Scientists to turn the moon into a sun. In the Videogame Marathon (1994 BS, Mac; 2011 iOS) (see Marathon Trilogy), Deimos is converted into a gigantic Spaceship.
The moons are also moved in Weldon J Cobb's At War With Mars, or The Boys Who Won (27 September-27 November 1897 Golden Hours; 1907), where the Martians move Phobos out of its orbit to use it as a Space Station; in the videogame Doom (1993), an experiment in Matter Transmission on Phobos transports Deimos into another Dimension; in Greg Bear's Moving Mars (1993), Phobos is teleported into Earth orbit; and in Steve Alten's Phobos: Mayan Fear (2011), Phobos is moved in order to destroy a miniature Black Hole. In the Wargame Warhammer 40,000 (1987), Phobos has been shifted into an orbit around the Saturnian moon Titan.
Because of their small size, it has been posited that the moons are actually spaceships, as in Hudor Genone's Bellona's Husband: A Romance (1887) and Donald A Wollheim's Secret of the Martian Moons (1955). Phobos is an ancient satellite constructed by Martians in the videogame Armored Core 2 (2000). In Arkady and Boris Strugatski's Noon Universe, Deimos and Phobos were constructed by aliens. More strangely, in D F Jones's Colossus and the Crab (1977), the moons are intelligent beings, while in the videogame Afterlight (2007), the moons are the pieces of an enormous alien creature.
Some stories set on a Martian moon are fanciful: in Edgar Rice Burroughs's Swords of Mars (November 1934-April 1935 Blue Book; 1936), one book in his Barsoom series, John Carter travels to Phobos (here called Thuria), shrinks to tiny size (see Miniaturization), and is captured by hostile creatures who use psychic powers to make themselves Invisible. Harl Vincent's "The Lost City of Mars" (February 1934 Astounding) describes Phobos as an artificial world with a race of Martians in its interior. In James's "The Crystal of Madness," Deimos is said to be inhabited by spider-like creatures. Somewhat more realistic is Ralph Robin's "The Pygmies of Phobos" (April 1936 Amazing), wherein an intelligent Martian race of tiny protozoa migrates to live on Phobos. In the videogame Leather Goddesses of Phobos (1986), the eponymous Aliens undertake to conquer the Earth. In Paul Capon's Phobos, the Robot Planet (1955; vt Lost: A Moon 1956), Deimos is inhabited by Robots; Festus Pragnell's "Devil-Birds of Deimos" (April 1942 Amazing) describes the eponymous creatures; and Dinosaurs are discovered on Phobos in Charles L Fontenay's Kipton on Phobos (1999). Astronauts who crash-land on Phobos encounter a strange alien in Cherry Wilder's "The Phobos Transcripts" (in New Writings in SF 26, anth 1975, ed Kenneth Bulmer). In the Doctor Who audio drama Phobos (2007), the Doctor visits Phobos and finds an unfinished hotel and hostile aliens; in another audio drama, Deimos (2010), he also encounters aliens on Deimos.
Sometimes, a Martian moon serves only as a place for spaceships to stop before landing on Mars, as in Laurence Manning's "The Voyage of the Asteroid" (Summer 1932 Wonder Stories Quarterly) and Robert A Heinlein's The Rolling Stones (1952). And in the Men into Space (1959-1960) episode "Flight to the Red Planet" (1960), Colonel McCauley and crewmates land on Phobos to prepare for a later landing on Mars. Space travellers land on Phobos before proceeding to Mars in the film Mechte Navstrechu (1963), radically remade as Queen of Blood (1966). In an episode omitted from the novel and film 2001: A Space Odyssey (1968) and recounted in Clarke's The Lost Worlds of 2001 (1972), David Bowman has travelled to Phobos and is planning to take a shuttle to Mars when he is summoned to become part of the crew of Discovery. Going the other way, the protagonist of Robert A Heinlein's Podkayne of Mars (1963) leaves Mars and stops at Deimos on her way to Earth. In a lost episode of Space Patrol (1950-1955), the crew takes a "Trip to Deimos" (1953).
Stories about people landing on an uninhabited Martian moon include Francis Trego Montgomery's On a Lark to the Planets: A Sequel to the "Wonderful Electric Elephant" (1904), which describes space travellers who visit the moons of planets in the Solar System, and J Harvey Haggard's "Castaways on Deimos" (August 1933 Wonder Stories), wherein a spaceship damaged by meteors is forced to land on Deimos, which is desolate and lacks an atmosphere. In Frank K Kelly's "The Radium World" (February 1932 Wonder Stories), humans find radium on Deimos, leading to a dispute between Earth and Mars over who will be able to mine this valuable metal. In Clarke's "Hide-and-Seek" (August 1949 Astounding) a man who landed on Phobos manages to avoid his enemies by running across the surface; the story was revised and expanded by Paul Preuss as Hide and Seek (1989). In Festus Pragnell's "Conspirators of Phobos" (June 1943 Amazing), heroic Don Hargreaves battles pirates. After a rogue Computer destroys a Space Station in Space Men (1960), one crew member manages to land on Phobos. In Ty Drago's Phobos (2003), a mystery unfolds at a scientific base on Phobos. The caves of a mostly hollow Phobos are explored in Mary Robinette Kowal's "The Phobos Experience" (August 2018 F&SF); another story about a hollow Phobos is Tom Purdom's "Romance with Phobic Variations" (February 2001 Asimov's). Part of Caitlín R Kiernan's tale about Androids, "Zero Summer" (2007 Subterranean) takes place on Phobos. In an episode of Captain Scarlet and the Mysterons (1967-1968), "Shadow of Fear" (1968), Captain Scarlet uses Phobos to survey Mars in search of the Martian Mysterons.
The Martian moons are occasionally used as bases, usually by evildoers, though in Garrett P Serviss's Edison's Conquest of Mars (first appeared 12 January-10 February 1898 New York Evening Journal as "The Conquest of Mars"; 1947; cut vt Forrest J. Ackerman Presents Invasion of Mars 1969), inventor Thomas Alva Edison makes Deimos his headquarters as he prepares to conquer Mars. Jack Williamson's The Legion of Space (April-September 1934 Astounding; rev 1947) describes how Phobos has been Terraformed to serve as the private estate of a powerful family. A criminal has his base on Deimos in the second issue of the comic Space Patrol (1952). Phobos is an alien monitoring base in James Blish's Mission to the Heart Stars (1965), while in the videogame Zone of the Enders: The 2nd Runner (2003), Phobos is the site of an enemy battle station; and in the videogames Warframe (2013), Destiny (2014). Unreal Tournament (1999) and Unreal Championship (2002), fierce one-on-one battles occur on Phobos. (Deimos is also featured in Unreal Tournament 3 [2007].) In Alastair Reynolds's story about conflicts on Mars, "Great Wall of Mars" (February 2000 Spectrum SF), one faction places its destructive machines on Phobos, while in the same author's Century Rain (2004) it is the site of an alien device that transports the protagonist to an Alternate World. In "The V.C.'s" (1979-1980), a series published in the comic 2000 AD, Phobos, now called Phobos Harbour, is a base for human starships. Evil aliens have established a base on Phobos in the videogame RTS RedRock (2003). In Dan Simmons's Olympos (2005), the half-organic, half-machine "moravecs" also have a base on Phobos.
Martian moons are used as Prisons in Neil R Jones "Escape from Phobos" (February 1933 Wonder Stories), the Role Playing Game Mutant Chronicles (1993), the Halo games, and the videogame Descent 3 (1999). Robots are mining Deimos in the Astro Boy (2003-2004) episode "Destination Deimos" (2004). In Isaac Asimov's "The Martian Way" (November 1952 Galaxy), "Scavengers" from Mars search space for discarded Earth-to-space booster rockets and take them to Phobos to be reused for new purposes.
Other stories involving the Martian moons are James B Alexander's The Lunarian Professor and His Remarkable Revelations Concerning the Earth, the Moon and Mars; Together with an Account of the Cruise of the Sally Ann (1909), explaining how the residents of the Moon negotiate with Martians to obtain control of the two moons; R Norman Grisewood's Zarlah the Martian (1909), about a Martian airplane that crashes into one moon; Henrik Dahl Juve's "The Martian Revenge" (August 1930 Wonder Stories), wherein a spaceship affected by Phobos's gravity crash-lands on Mars; and Philip Reeve's Larklight (2006), which mentions factories on Phobos and Deimos. A man has his consciousness trapped inside a computer on Deimos in Alastair Reynolds's "Things to Do on Deimos When You're Dead" (September/October 2022 Asimov's).
Overall, Phobos and Deimos are undoubtedly the smallest worlds in the solar system to appear in numerous sf stories, but this can be explained by their proximity to Mars, the most frequently visited planet. It is a tribute to the imagination of sf writers that they have been able to create a variety of interesting stories about what are probably two very ordinary large rocks. [GW]
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