Fictional trans-Neptunian planets

The hypothetical trans-Neptunian planets are hypothetical or fictional planets on the edge of the Solar System, beyond the orbit of Neptune, which sometimes serve as settings or references in science fiction. A hypothetical trans-Neptunian planet was sometimes referred to as "Planet X", where "X" signifies an unknown quantity as this was coined before the discovery of Pluto in 1930. Following its general reception as the ninth planet of the Solar System, a hypothetical additional planet was sometimes called a "tenth planet". An informal SF tradition assigned the Solar System's tenth planet the name "Persephone".

Tenth planet

Fictional references to a "tenth planet" include:

Literature

*In H. P. Lovecraft's Cthulhu mythos, Yuggoth (or Iukkoth) is identified with Pluto by Lovecraft himself; however, other writers claim that it is actually an enormous, trans-Neptunian world that orbits perpendicularly to the ecliptic of the solar system, accompanied by three moons: Nithon, Thog and Thok. Yuggoth first appears in "The Whisperer in Darkness", written in 1930, more or less simultaneously with Pluto's discovery.
* In Robert A. Heinlein's novel "The Puppet Masters" (1951), a character names the planets in the solar system; after Pluto comes Kalki.
* In Robert Anton Wilson's "Schrödinger's Cat trilogy" (1980), the tenth is named Mickey (and the eleventh Goofy).
* The first part of "The Forever War" (1974) by Joe Haldeman is set on a transplutonian planet called Charon. This is not Pluto's moon, as the story was written before Charon's discovery (1978).
* In the trilogy "The Tenth Planet" by Dean Wesley Smith and Kristine Kathryn Rusch, a tenth planet circles the Sun and its alien inhabitants periodically harvest Earth's resources.
* The radio play "The Tenth Planet" by Milton Geiger (not credited) was broadcast Sept. 7, 1952 on Hollywood Star Playhouse. It starred Joseph Cotten, Hans Conreid, and Joan Banks Lovejoy. Cotten is kidnapped by aliens inhabiting a planet beyond Pluto.

Animation

* In the anime series "Space Battleship Yamato" (1974) (known in North America as "Star Blazers") there are eleven planets in the solar system. The tenth is only ever referred to as "Planet 10", but the eleventh is given the name of "Brumus".
* In the popular Japanese anime "Sailor Moon" (1992), in both the manga and the anime, there exists a 10th Planet called Nemesis which is controlled by Death Phantom from the Black Moon Clan. The planet was said to be radiating negative energy and can disappear from sight, only trackable via X-rays. This may possibly be a reference to the star, Nemesis, the postulated stellar companion to our Sun.
* In the animated television series "Exosquad" (1993), the Solar System contains an invisible tenth planet composed of dark matter. It was discovered by the Pirate Clans who named it Chaos and later offered it as safe haven to the Exofleet.
* In the "Mutant Chronicles" universe (1993), the 10th Planet, Nero, is the home of portals used by The Dark Legion to gain access into our galaxy through which they plan to enslave or destroy mankind. The planet is named after the Imperial Cardinal who had prophetic visions of the black planet, visions which also warned him of death.

Film

* The 1984 cult film "The Adventures of Buckaroo Banzai Across the 8th Dimension" has aliens from Planet 10 crossing the eighth dimension and invading the Earth, although the novelization clarifies that this is intended to be the tenth planet of a distant star, not our own solar system.
* In the motion picture "K-Pax" (2001), the character played by Kevin Spacey, an alien, tells the character played by Jeff Bridges that there are ten planets in Bridges's solar system.

Comics

*In "Camelot 3000", scientists discover a tenth planet in 3000 AD. It is later revealed to be the homeworld whence the aliens (led by Morgana LeFay) attack Earth. Eventually King Arthur and his Knights of the Round Table are teleported there with the help of the Lady of the Lake.
* The "Judge Dredd" comic strip in "2000 AD" has a tenth planet called Hestia, which actually orbits the Sun at nearly the same distance as the Earth but at such an angle to the plane of the other planet's orbits that it was not discovered until 2009. It is inhabited by a small colony of humans. However it also has an intelligent indigenous population, who keep their distance from the colonists. The planet is also home of the lethal Dune Sharks (flying shark-like predators which can burrow beneath the ground), some of which were transported to Earth by persons unknown, and which now inhabit the Cursed Earth desert.
* In "2001 Nights" by Yukinobu Hoshino, Night 7, "Lucifer Rising", describes the discovery of a tenth planet dubbed Lucifer and its three moons Cassius, Brutus, and Judas. The expedition to Lucifer becomes a perilous and tragic one when it is discovered that Lucifer is composed of antimatter.

Games

In the computer game "" there is a tenth planet called the "Dark Planet" that was not discovered for some time because it was obscured by the Kuiper belt.

"Persephone"

Persephone is a name frequently put forward for a future tenth planet as she was Pluto's wife:

* In Larry Niven's "Known Space" universe (1964 onward), Persephone is a small gas giant with a single moon, Kobold.
* Although not considered canonical, a 1970s publication by Bantam Books entitled "Star Trek Maps" suggests that, in the "Star Trek" universe, the solar system has a tenth planet called Persephone that orbits at a great distance from the Sun. No canonical film or TV episode has yet supported this, however, and a later, similar work, "Star Trek Star Charts" by Pocket Books makes no mention of this world.
* Arthur C. Clarke made several references to a tenth planet called Persephone in his fictional works, including the novel "Rendezvous with Rama" (1972).
* In Douglas Adams's novel "Mostly Harmless" (1992), the tenth planet is officially called Persephone, but nicknamed Rupert (after "some astronomer's parrot"), and is inhabited by the crew of a spaceship who have forgotten almost everything about their mission, except that they are supposed to be "monitoring" something.

"Planet X"

Fictional references to "Planet X" include the following; see also Planet X (disambiguation).

Literature

* Donald W. Horner, in "Their Destiny" (1912), described spaceflight to Alpha Centauri by astronauts who, as they leave the solar system, pass a planet beyond Neptune. This work was written before Pluto's discovery in 1930.
* In the Cthulhu Mythos, Planet X may be either Ghroth or Yuggoth, though the latter is normally believed to be Pluto.
* One of the Tom Swift, Jr. novels, "Tom Swift and the Visitor from Planet X" uses "Planet X" to designate an apparently inhabited distant world from which the young inventor may be receiving messages.

Film

* The low-budget, black-and-white sci-fi classic "The Man from Planet X" (1951) [imdb title|0043778|The Man from Planet X (1951)] is said by some to be the first authentic space-alien movie — although some would give that distinction to "The Thing from Another World" (1951).
* In the sixth "Godzilla" film, Monster Zero, aliens, known in Japan as X-seijin and in America as Xians, hail from Planet X (located between Jupiter and Saturn). Because water is scarce on the planet, the aliens try to conquer the Earth to take its water supply.
* [http://www.planetxvideo.com Documentary series about Planet X Nibiru]

Animation

* In some "Looney Tunes" cartoons set in space, such as "Duck Dodgers in the 24½ Century", there is a "Planet X". The name is noted by a bland sign sticking out saying "PLANET X", a giant letter X on the planet's surface, or the planet having an X shape. In "Duck Dodgers", Planet X is located by following a trail of planets respectively labeled A, B, C, and so forth.
* The animated television series "Exosquad" depicts Planet X as an invisible world composed of dark matter. It was discovered by the Pirate Clans who named it Chaos and later offered it as safe haven to the Exofleet.
* In "", Planet X is a mysterious X-ringed purple mechanical planet that is the home of Sideways and Soundwave.
* In the Japanese animated series, "Sailor Moon", Planet X is called "Nemesis" and it is the home and base of the enemy from the Dark Moon clan.
**In the Sailor Moon Musicals, another Planet X called Vulcan is a key part of three musicals. It is said to be on the other side of the sun
* In the claymation series "Huxley Pig", the titular character imagines himself flying to a fast-food outlet on Planet X.

Games

In the videogame "", Planet X is said to initially exist between Neptune and Pluto and causes the two planets to switch positions in the solar system while Planet X itself becomes the literal tenth planet in the system and is shown to be artificial, though mountains and jungles exist on it. In the videogame "Timesplitters 2" thre's a level called Planet X, where the character fights against two kinds of extraterrestrials.

Other

In "Zombies from The Beyond", an off-Broadway musical which parodies 1950s B-Movies, the play's antagonist, Queen Zombina, comes from Planet X to abduct Earth men in order to repopulate the planet, after all the males were killed in a nuclear war initiated by the oppressed female denizens.

Notes