Planet Spaceship

"...Brave as fools and bold as gods, they built an armada of swift little ships and raced out to meet me, and to my utter amazement, I discovered that I was enormous — bigger than worlds, massive and enduring, and in their spellbound eyes, beautiful."

— Great Ship

There's big spaceships, there's gigantic spaceships, and then there's these: a spacefaring ship or structure that is so massive it may evoke "That's No Moon" when it first appears. At the low end it may be large enough to house a crew of several million, and in some cases could be considered a self-contained city with their own districts, marketplaces, parks and school zones. In space, you have no external gravity to contend with, so it's possible to build some truly humongous structures like this. Alternatively, you may just want to strap some engines onto an actual planet or moon and set off, although this may require Sufficiently Advanced Technology. If the ship's big enough, it may even have its natural gravity be big enough to keep things rooted to its surface, though usually not enough to make an earth-like atmosphere (like, say, our moon).

Often used for Rule of Cool, in which case it will overlap with Cool Starship, the Planet Spaceship is a great demonstration of industrial might that will be intimidating to anyone on a lower level. It can also be used to pack your entire population off when your home world is in trouble.

Technically, actual planets and moons are spacecraft in the sense that they are in orbit around something. Buckminster Fuller made this analogy when he referred to "Spaceship Earth." But to qualify for this trope, the super-colossal spacecraft must have some means of propulsion, or at the very least orbital correction.

Sub-Trope of Mile-Long Ship and Planetary Relocation. May be used as a Big Dumb Object, The Battlestar, or a Generation Ship. Commonly, though not exclusively, found in Space Opera. Compare Dyson Sphere and Ring World Planet. See also: Unnecessarily Large Vessel, Unnecessarily Large Interior and Awesome, but Impractical.

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Examples:

Anime & Manga

• Doraemon Film Series:
  • The Milky Way Drifting Fleet from Doraemon: Nobita's Drifts in the Universe is a giant, planet-sized spaceship constructed by the humans of Planet Laguna 300 years ago to escape their doomed planet. Over the centuries the Fleet gets bigger as bigger when aliens from different worlds begin taking refuge aboard, and when Doraemon and friends arrive they realize it to be the home of millions upon millions of aliens, humans and robots from all across the galaxy.
  • Doraemon: Nobita's Treasure Island have the titular island which is actually a floating city housing hundreds and hundreds of people, with the captain, Silver, intending to convert into a space colony by draining energy from the earth's core and then launch it into the galaxy. Unfortunately this could result in an Earth-Shattering Kaboom, necessitating the heroes to stop him in the climax.
• Lord Slugg's planet-ship in Dragon Ball Z. It's actually a regular ship attached to whatever planet it conquered and terra-froze.
• Gundam:
  • Gundam 00: A Wakening of the Trailblazer shows the massive main ship of the ELS, a massive ship with the diameter of approximately 3000km made up of sentient living metal.
  • The manga Enhanced human tale: MAD WANG 1160 mentions planet-sized ships but also claims their large size tend to make them a big target thus are relatively rare.
• There's a ship in the Raalgon fleet, in Irresponsible Captain Tylor, that causes Tylor himself to comment that it's "more like a planet than a ship".
  • And it is outclassed by an even bigger ship in the final OVA.
• In the five-part series finale of Kirby: Right Back at Ya!, Nightmare Enterprises is revealed to be housed by a massive space station that's about the size of a small planet.
• The Macross series has more than a few:
  • The Zentradi Fulbtzs Berrentzs-class Main Base in the original series is hundreds of kilometers across. Of course, the Zentradi themselves are giants.
    • Right before the battle against the Zentraedi's full force, Exedore, a Zentraedi defector, had established that fleet as the 118th Main Fleet, hinting there's others. Later in the Post-Script Season it's established there are, with an estimate of their number being between one and two thousands... And that's after their numbers were reduced by millennia of warfare and the fall of Protoculture (the Zentraedi's original creators) preventing the construction of more.
    • The Zentraedi also have factory satellites almost as big as a Main Base to replenish their fleet numbers and clone new personnel. Each Main Fleet has between 20 and 50... And the UN Spacy is stealing every single one they can find, and looking for the one that can build Main Bases.
  • Macross: Do You Remember Love?, has two main bases. Thankfully, their respective fleets are on opposing sides.
  • In the Macross Frontier movies it turns out the Main Base of the 118th Fleet had not been completely destroyed, but rather half of it, due the damage suffered in the battle, has folded away... And it's now being used by the Vajira as a nest.
  • The alternate universe of Macross II has the Marduk flagship, as befitting of someone who managed to brainwash into obedience a large number of Zentraedi ships.
    • Expanded Universe about this timeline states that, between DYRL and this series, five Main Fleets have shown up, each with their own Main Base.
• In Outlanders, Earth's Moon is revealed to be a millennia-old ship, the superweapon called "Dola".
• Tenchi Muyo!:
  • The Kuramitsu family have a planet-sized spaceship called that can destroy planets and seems to be a nod to the Death Star from Star Wars.
  • Some Space Stations are larger than planets, like the Galaxy Academy being the size of a solar system.
• In Tengen Toppa Gurren Lagann, the final battle has the two sides fighting with mechas that are on the same scale as galaxies!
  • You don't even need to go that far to find planetoid-sized vessels in TTGL. The Super Galaxy Gurren Lagann/Cathedral Terra was large enough to be disguised as the Moon.

Comic Books

• 2000 AD:
  • The Ten-Seconders: Sort of. The "Fathers" of the superhero-esque Gods live in a spaceship big enough to easily engulf Planet Earth.
  • Shakara:
    • The Succubi hive species travel around in cosmos crafts that are about the size of a small planet.
    • Shakara himself uses a World Engine to transform an entire planet into a giant rocket, using it to blast through an alien fleet.
• DC Comics:
  • There are several associated with Green Lantern:
    • Mogo, the Sentient Planet, is a Green Lantern, and effectively becomes this as he can travel through hyperspace.
    • Mogo also has a rival in the Yellow Lantern Ranx the Sentient City, who was once prophesied to destroy Mogo and was rather eager to fulfill this prophecy.
    • In DC`s New 52 Green Lantern: New Guardians series there was a whole artificial solar system, with inhabitable interiors for various species, it was built to replace the star system Larfleeze the orange lantern inhabits.
  • Legends of the Dead Earth: In Justice League America Annual #10, Lord Havok created a giant spaceship called War World which contained an artificial environment emulating a planet. He used the ship to travel the cosmos and find human colonies, which he conquered.
  • Superman:
    • War World: The eponymous mechanical world is a mobile, star-sized weapon-planet. It has frequently fallen into the hands of Mongul and other galactic conquerors.
      Superman: "It's Warworld! I've spotted it — only a couple of light-years away! It's about to pass in front of that white dwarf star and... and... Great Rao — It's not possible! Nothing artificial could be that huge! Warworld didn't pass in front of the star — It passed behind it! And the dwarf star's overwhelming gravitational pull had absolutely no effect on it!"
    • In The Planet Eater Trilogy, Brainiac devises a mechanical world-ship capable of travelling around the galaxy and swallowing whole planets.
  • Wonder Woman:
    • Wonder Woman (1942): The Green Geni have converted their planet into a ship which somehow runs on the nuclear crystals they're so fond of.
    • Wonder Woman (1987): The Sangtee Empire has space-faring cities that double as mobile spaceports that look a bit like a city in a snowglobe with a small dome on top and many shuttered ports in the base.
  • Tyr from the Legion of Super Villains gutted his home planet, Tyrraz then converted it I to a spaceship and went around attacking other planets.
• Disney Ducks Comic Universe stories from Italy have more than a few:
  • The first to appear is Pacificus, Reginella's homeworld. It doesn't have full control over its course, but can change speed and maneuver on a number of pre-decided routes.
  • The second is Vampirione. It has better maneuvering abilities than Pacificus but is slower, as shown when its inhabitants chase Pacificus to try and steal all its resources.
  • The Evronians from Paperinik New Adventures love this trope:
    • At some point in the past they took a moon of their homeworld and turned it into a spaceship. Never appeared on page and is only mentioned in the inserts, but may have been destroyed off-screen by Xadhoom (the flashback showing her destroying one such place shows one that doesn't exactly look like the one we saw her destroy on-page).
    • Zotnam's mothership is relatively small, only 500 km long and tall. Fate of this one unknown.
    • The "Xadhoom's Trilogy" provides a third, described the size of a small planet. It's ultimately wrecked by Xadhoom and a Coolflame revolt and explodes.
    • The first relaunch story, "Might and Power", shows that the Evronians in the Bad Future did it again: they transformed another planet in a spaceship, in this case Earth. It took them two hundred years.
    • A fifth shows up in "Chronicle of a Return", surprising Paperinik because he thought they only had one. Much to his horror, the Evronians there explain him that they do it regularly: whenever the population of one grows too much they build one or turn a planet into one, divide their population in two, and then the two spaceship go their separate ways, ready to repeat the process when the population grows too much again. Also effectively confirming that Xadhoom had destroyed two Evronian planet spaceships... But maybe not the original.
• Taa II, the Worldship belonging to the Marvel Comics character Galactus, and named after his ravaged homeland Taa, is the size of a solar system.
• The Empyreon in Khaal: The Chronicles of a Galactic Emperor is an ancient prison ship so massive its capable of supporting its own (dwindling) ecosystem and homes three separate civilizations that are fighting among themselves for its scarce resources.
• Star Trek: Mission's End takes place on Archenar-IV. Originally it was merely a giant spaceship, but its original crew disappeared. In the thousands of years since it insect population has evolved sentience and treat the place like their home planet.
• The Transformers (Marvel): Megatron wanted to turn its artificial homeworld Cybertron into this, but never managed it.
• Issue 12 of Invader Zim (Oni) shows that in the Bad Future, Emperor Zim is planning to convert Earth into a spaceship and fly it to the Tallest. So they can cut it in half and turn it into a giant snack bowl.

Fan Works

• A Crown of Stars: In an early chapter Asuka visits the HMS Asuka Langley Sohryu, a moon-sized space-ship named after her. The Avalon Empire has a lot of planet-sized ships.
• The Daria Expanded Universe has the Corps of Ringbearers, who police the various realities for supernatural threats. Their greatest weapons are the seven Sky Vaults, each of which is roughly one-third the size of Earth's moon. They are fearsomely armed with five solar cannons, a wealth of other armaments - but are considered to be weapons of last resort or of final escape in order to save as many species as possible from an omniversal threat to Reality itself. The Corps took the latter option during The Judith Saga, and haven't been seen since.
• Earth's Alien History has Concourse, a dead planet that the Harvesters hollow out and convert to a ship in order to act as a mobile and neutral headquarters for the Shield Alliance.
• In the RealityCheck's Nyxverse story Alicornundrum, it's revealed that the entire world was converted by their ancestors into a planetary ship to escape their doomed star system, and all natural phenomena must now be made and administered by its inhabitants, including the artificial sun and moon.
• Deconstructed in the Star Wars Copypasta SDSD Freudian Nightmare, about an Imperial Grand Admiral testing out a Super Star Destroyer. The ship takes nearly a week to tour. On top of which, it's own gravitational pull causes the wastewater to spill into the ventilation system, causing a plague. Due to this, the various personell descend into tribalism, with the Corps of Engineers declaring themselves "The Sovereign Nation of Ree'Ak'tor," and the stormtroopers becoming a Cult called "The Bringers of the Apocalypse." It takes two hours to turn the damn thing, and it flyswattered an entire fleet of allied ships by accident.
• The Ship Moves is a fanfic based on Warhammer 40,000 where the God-Emperor awakens and orders the construction of a starship 1 AU in length, with otherwise unusual assistance of species outside of humanity to handle the impossible requirements to make this work, so that they may abandon the Milky Way and head toward a destination only the God-Captain knows.

Film — Animated

• In Home (2015), the nomadic Boov travel across the cosmos in an absolutely titanic starship in their search for a new home.
• In The LEGO Movie 2: The Second Part, Queen Watevra Wan'abi bribes Captain Metalbeard with a planet that's also a pirate ship.
• Titan, for which Titan A.E. is named, is a very large, spherical spaceship. When activated, it converts energy into mass and creates an actual planet.
• There were two in earlier concepts for The Transformers: The Movie:
  • The early "The Secret of Cybertron" concept, the Transformers' home planet Cybertron was going to turn out to be a giant Transforming Mecha.
  • A later draft had Junkeon turn out to be one with the Autobots flying it to Cybertron rather than finding a ship. This made it into Marvel's Early Draft Tie-In Comic-Book Adaptation.
• Time Masters ends on a planet-sized Space Station divided into two hemispheres.

Film — Live Action

• The titular artificial Ring World Planet in Elysium is a space habitat for wealthier classes after an apocalyptic overpopulation crisis on Earth. It is built in a ring like shape that rotates to maintain gravity and has a breathable Earth like surface. Elysium is built close to Earth to work as a Conveniently Close Planet so trips between the two worlds, both for poor people buying their way up and agents of Elysium handling security problems on Earth, are as fast as possible.
• The alien mothership in Independence Day was estimated to be several hundred kilometers in diameter. Independence Day: Resurgence tops it with a larger mothership that dwarfs the Atlantic Ocean and has its own ecosystem.
• In Little Shop of Horrors, Audrey II beams down to Earth during an unprecedented eclipse, implying that he came here in a spaceship large enough to block out the sun.
• Star Trek: The Motion Picture: The entity V'ger possessed a cloud concealing its core form, the theatrical version said that cloud was 82 astronomical units, making it the size of the solar system. The Director's Cut changes it to 2 AU which is still twice the distance from Earth to the sun. The physical ship discovered at the center was said to be 48 miles long according to Deleted Scenes and the novelization.
• Star Trek III: The Search for Spock introduces Starfleet's Earth Spacedock, an enormous structure in Earth's orbit at least several miles tall and at least several dozen starships can dock inside the upper dome section.
• Star Trek Beyond has Starbase Yorktown, a moon-sized space station that contains interlocking rings for habitation, the equivalent of several planetbound cities holding millions of people.
• Star Wars:
  • The Death Stars in A New Hope and Return of the Jedi are moon-sized superweapons, the first of which being the original source of the That's No Moon trope. For specificity's sake, the first Death Star was established as 120 kilometers in diameter, and the second would've been either 160 kilometers or 900 kilometers (there are contradictory sources) if it hadn't been blown up first.
  • The Force Awakens: Starkiller Base is a souped-up Death Star. It's an alpine planet that's been converted into a superweapon, making it many times larger than the Death Star. While it is never shown moving, since it eats stars to fuel its super-cannon, it was presumably intended to relocate once the system it was in ran out of stars to eat.
• In Transformers: The Last Knight, Quintessa has converted the remains of Cybertron into one that's slightly larger than the moon and flown it to Earth. Earth itself is revealed to be the gigantic transformer, Unicron.
• In Ultraman Cosmos: The First Contact, the ruins of Planet Baltan, in the aftermath of a nuclear war, has been converted into a spaceship housing millions upon millions of Baltanian children, with their leader Basical Baltan as the navigator and caretaker actively looking for a new planet for his kin. Basical's decision to claim planet Earth as a new home is what kickstarts the plot of the film.
• In Ultraman Zero: The Revenge of Belial: Belial's Empire mothership designed after his hand, the Malebrandes is a planet-sized base of operations that Belial uses to fabricate his armies in and literally take over worlds under his rule.
• The planet Mongo is mobile and controlled by Emperor Ming in the Flash Gordon (serial). Its near collision with Earth was no accident.
• Alpha from Valerian and the City of a Thousand Planets. It started as our world's ISS, then other nations of the world expanded it with their own vessels, then alien vessels from all over the universe expanded it further. It size and mass started causing a serious problem to Earth and thus Alpha was freed from its orbit.
• The Chinese film The Wandering Earth is focused around a human effort to move the Earth from our Solar System to Alpha Centauri to avoid the Sun going red giant within the span of centuries instead of billions of years. As the process of moving away from the Sun freezes most of the planet's surface, humans mostly live in underground cities close to the giant engines pushing the planet.

Gamebooks

• Space Assassin: The entire adventure is set on board a massive spaceship called the Vandervacken, the base of the Mad Scientist and Evilutionary Biologist Cyrus, which contains near-endless corridors and rooms along with a vast section of alien countryside.

Literature

• 2312: In a small-scale example, many of the orbiting habitats in the Colonized Solar System are "terraria"; a planetoid or large asteroid hollowed out, set spinning to provide centrifugal gravity, and populated with an ecosystem of plants and animals. Water, atmosphere, and soil are derived from the asteroid's original material or brought in from other bodies, and an artificial "sunline" along the axis of rotation provides light for the plants. Main character Swan mentions a period of her career that was spent designing biospheres for various habitats.
• In The City and the Stars, it is revealed at the end that most of humanity left the Galaxy to explore the universe... in a star cluster made into a fleet.
• The Polish young adult sci-fi novel Ci z dziesiątego tysiąca (Ones from the Tenth Thousand) by Jerzy Broszkiewicz mostly takes place on a "mechanoplanet": a large, intelligent spherical spaceship with artificial environment.
• Cradle Series: A necessity for the Vroshir. The void between universes is nothing but corrosive, horrific Chaos. The only thing that keeps it at bay is a healthy world with millions of living human souls. The Abidan control and watch over normal worlds, but the Vroshir are those who are criminals under Abidan law, so they can't find safety there. The solution is to kidnap people by the millions and force them to live on nomadic planets, giving the individual Vroshir a mobile base of operations.
• The larger models of Culture General Systems Vehicle from The Culture fall here. The things can be anywhere from 25 to 200 kilometres in size, carry billions of passengers, and can match entire multi-planet empires for manufacturing capacity and raw power generation. One scene shows kilometre-long oceangoing ships being packed away for storage inside a GSV. Perhaps even more impressive, the Culture incorporates hundreds of thousands of GSVs by the later Culture novels.
• Empire from the Ashes has Dahak and all the other Imperial Planetoids. Dahak has spent the last 50,000 years pretending to be Earth's Moon... and it's the smallest of them. They come equipped with hundred-kilometer-thick armor and carry 80,000-ton battleships as parasite craft.
• In the short story "The Funhouse Effect" by John Varley, a large comet in a close solar orbit is partially hollowed out, has engines mounted on it and is being used for exclusive pleasure cruises 'round the Sun.
• Gaea Trilogy: Gaea and her brood are living space habitats large enough to be mistaken for additional moons of Saturn.
• Cordwainer Smith gives us The Golden Ship, a sphere 90 million miles in length (just 2 million miles short of an AU). That's approximately 100 times larger than Earth's sun! Extremely fast, it could move in seconds. However, the Golden Ship is really a decoy, being mostly hollow and consisting of foam and wires. It has no weapons of its own and must rely on its speed to survive.
• Gor:
  • The planet Gor itself can be considered an example, since the Priest-Kings moved it to its current location 5 million years ago.
  • The Kurii live in "Steel Worlds" in the asteroid belt; from there they plot their plans to destroy the Priest-Kings and take over Gor & Earth for themselves. The Steel Worlds have artificial weather & daytime/nighttime and rotate to simulate gravity, with beings living on the inside circumference of the ships. They used to have a planet of their own but they destroyed it making war with each other.
• In Great Ship, the Great Ship itself is an ancient abandoned artifact which was claimed and settled by mankind's descendants. It is larger than Jupiter. The interior of the ship has hundreds of thousands of enormous caverns which are inhabited by the passengers. The ship has fourteen gimbaled engines on one end, which are fed from dozens of hydrogen fuel tanks whose individual volume exceeds that of all the Earth's oceans combined by several orders of magnitude. In The Well of Stars, a planet weapon is shown - the Sword of Creation - a planet-wide hyperfiber ring which has microscopic black holes tethered to its rim, which is then spun up and repeatedly launched at planets to expose a path to its core for mining.
• At the end of Halo: The Cole Protocol, the Rubble's inhabitants, who are survivors of the previous Covenant invasion of their system, convert a large asteroid into an evacuation ship to get everyone safely to UNSC space.
• In the Ted Reynolds short story "Ker-Plop", we get a reminder of the difference between size and volume, when humans return from the Magellanic Clouds in a ship that is ten thousand kilometers across (for comparison, Earth is a little over 12,000km across). The agent sent to investigate realizes that because the entire volume is inhabited, rather than just the surface, this one ship contains more people than his entire galactic federation. The decks are arranged concentrically, like an onion, and the first kilometer alone has nearly 400 decks, each with nearly the same surface area as the entire ship!
• In Known Space, the Pierson's Puppeteers are a race of cowards, and the only Puppeteers humans have met are insane — because no sane Puppeteer would trust his life to something so fragile as a spaceship. So when they discover a massive wave of radiation approaching their home system, they leave it behind... but take their planets with them. They put them in orbit around each other (see Klemperer Rosette on The Other Wiki) and accelerated them to just under lightspeed, heading out of the galaxy. Because humans have faster than light starships (which Puppeteers are too afraid to use), they expect humans to greet them at their destination, the Clouds of Magellan. They also in the process solved the problem of heat pollution, using it to keep them warm enough to be liveable while in the depths of space.
• In Lensman, armed planets with inertialess drives are slow (by Lensman standards — they can still travel much faster than light) but can mount much heavier weapons and shields than any built ship.
• In Los Altísimos by the Chilean writer Hugo Correa, Cronn is a planet of 33,000 kilometers in diameter inhabited by the Cronnios, which in reality are several planets hollow one inside the other, with oceans on both sides and floating continents. It is really a construction made by aliens that reach the level of Eldritch Abomination, so that the Cronnios inhabit it and can explore the galaxy and inform their discoveries to Los Altísimos.
• Lilith's Brood: The Oankali use their innate gift of genetic engineering to grow titanic, intelligent living "great ships" that transport entire planetary populations from world to world. Since they host entire ecosystems within their mass, including Arboreal Abodes for the Oankali, visitors often need to be convinced that they're not still on a planet. Growing a new one consumes enough mass to strip a planet to its core.
• In Macroscope by Piers Anthony, Sufficiently Advanced Technology allows four humans to turn the entire planet Neptune into a machine that can carry them to different locations in space instantly, tesseract-style.
• In Manifold: Origin, the Red Moon was built by the Downstreamers and programmed to teleport itself from universe to universe, abducting and dropping off various hominids from alternate Earths in order to advance human evolution.
• The My Teacher Is an Alien series has a ship called the New Jersey, so called because it's the size of New Jersey. (It's actually an alien spaceship, but christened by a fan of Earth.) Its inhabitants use Teleportation to get around rather than walk hundreds of miles from one place to another. It's mentioned off-hand that it's considered extremely small for a mothership due to the mechanics of spaceflight, and only possible because of cutting-edge new technologies.
• When the aliens of Orthogonal develop their Perpetual Motion Machine engines that are powered by light and consume (almost) no fuel, some characters discuss building massive engines on the Doomed Home Planet and "flying" the planet to safety like a straightforward Planet Spaceship. At/after the end of the trilogy, though, they instead put out the sun and build engines on its surface, so that they can move it and let its gravity take care of pulling the planet along, which will cause fewer seismic disturbances on the planet. This is at least partially justified in that, In-Universe, the sun actually is just a big ball of flammable rock that is on fire, not a ball of gas undergoing a continuous fusion reaction.
• In the Paradox Trilogy, the xith'cal have no colony worlds. They live on tribe ships, moon-sized spaceships which hold millions or even tens of millions of xith'cal.
• The largest vessels in the Perry Rhodan series fall under this trope. For instance the cosmocratic spore ships, spheres with a size of 1126 kilometers. Possibly the most extreme examples: Klongheim and Parsfon, the fully FTL-capable homes of rival robot civilizations traveling the universe in search of their rightful masters, with dimensions measured in light-months. It's strongly suggested that these got their start as remnants of some cosmic disaster or other that weren't so much built as colonized.
• In Primordial Threat, a black hole is about the pass through the solar system, destroying Earth in the process. A scientist identified the threat well before anyone else and managed to develop a technology that allows the Earth and Moon to cross interstellar space to settle in orbit of a new star.
• In Remnants, eighty humans blast off in a slapped-together rocket with experimental stasis technology in hopes of surviving when an asteroid hits Earth. Those who wake up initially think that they've landed on a bizarre alien world. They soon discover that it's actually a massive spaceship with artificial environments; its sentient (and unfortunately crazy) AI, Mother, brought them aboard as a curiosity. The dimensions of the ship are later given as about 100 x 150 miles.
• Skylark Series: Drs. Seaton and Crane build a 1000km diameter spaceship called the Skylark of Valeron. Its size was needed to house the sensors required to travel at its full velocity. Later, their rival Dr. DuQuesne builds an even bigger ship.
• Skyward: In Evershore, it's revealed that the planet of Detritus (where most of the series has been set) is capable of interstellar travel, being fitted with mechanisms to allow it to be teleported by a cytonic and with special gravity dampeners to minimize the stress on planets it teleports too close to.
• In the Star Carrier novels, the Turusch build their larger warships by hollowing out large asteroids and adding engines. An extreme example of this is the Regrets of Parting, made from a dwarf planet at least 900 kilometers in diameter and massing about 900 quadrillion tonnes.
• Star Wars Legends:
  • Zonama Sekot is a case of attaching absolutely enormous hyperdrive engines to a (sapient) Earthlike planet.
  • The Yuuzhan Vong have massive Worldships which hold most of the race's population. They were used by the Vong to travel from their galaxy to the galaxy of the protagonists. They're also used as warships, and are thrice the size of a Super Star Destroyer.
  • The Crystal Star has Worldships, artificial planetoids with hyperdrive engines. They're large enough that people on the surface can mistake them for planets and even have their own synthetic "suns", but are small enough to rely on artificial gravity.
• In Terre en fuite, Earth (with the Moon in natural gravitational tow) and Venus are turned into giant spaceships in order to allow humanity to escape the Sun going nova. Initially, the plan is to wait out the explosion behind Jupiter and come back. However, scientist then determine that the Sun will not return to its former state, so they have to move the planets to another system... and then again when the first one turns out to have a Lost Colony of humans.
• Edmond Hamilton gives us "Thundering Worlds", in which every planet in the solar system is outfitted with nuclear rockets and flown to another solar system to escape our dying sun. Of course, then they pass by some hostile aliens and give them the same idea...
• In the final book of the Tunnels series, Planet Earth itself is revealed to be one of these.
• In The Witches of Karres, the so-called witches use their "Sheewash drive" to move the entire planet of Karres around when they need to.
• The short story "With Friends Like These" by Alan Dean Foster has a literal Spaceship Earth, at the end. Aliens come to recruit humanity, who have been trapped on Earth after being kicked out of Galactic society for fighting. After they agree, the entire planet follows them, bringing the Moon along with it.
• In the Xeelee Sequence, humanity uses celestial objects in their misguided war against the lords of the baryonic universe, the Xeelee and their Great Attractor. In Flux, humanity converted a neutron star into a starship, sinking a Reactionless Drive beneath the crust, uploading minds into computronium in the core, and building nigh-microscopic human analogues to tend machinery on the crust. In the finale to the Vacuum Diagrams short story collection, the Qax lead an assault on the photino birds around the Attractor, using a red giant star as a flagship.

Live-Action TV

• In Andromeda, the Magog come from worlds (yes, that's plural — twenty of them) locked together in some kind of structure. The whole thing is mobile, FTL capable, and even contains an artificial sun. Oh, and it can survive a hit from a Nova Bomb, the largest weapon in the Commonwealth arsenal, normally capable of nuking entire solar systems.
• One of the First Ones featured on Babylon 5 operated a planet whose power source was the core of a planet, retrofitted for space travel. It even appeared to have a ring of moons.
• Doctor Who has had one or two in its 50-year history.
  • The Daleks attempted it in "The Dalek Invasion of Earth", intending to install an engine at the Earth's core, but failed.
  • Mondas in "The Tenth Planet" is implied to have some method of propulsion.
  • Zanak from "The Pirate Planet", a hollowed-out planet with massive transmat engines... it could materialize around another planet and capture everything from it, leaving behind a tiny husk, which its captain could collect as a trophy.
  • The Time Lords are shown to have the ability to move entire planets lightyears through space. Technically they can turn any planet into a spaceship, including their own.
  • The TARDIS itself definitely qualifies, just not on the outside. Its exact inner size is variable, but we know that it's large enough to contain an Eye of Harmony, a Time Lord power source built from a nearly-dead star in a perpetual state of gravitational collapse. The Doctor once claimed that if the TARDIS ever tried to land without its shell, the ship's true weight would crack the surface of the Earth. And even before that, he'd previously said that the TARDIS is, for all intents and purposes, infinite.
    • In an expanded universe novel the Doctor expands the TARDIS interior to encompass the whole Earth. It works, but the power drain nearly rips the TARDIS apart.
  • The Sycorax from "The Christmas Invasion" travel in asteroids and meteors that they converted into spaceships.
• In the Star Trek: The Original Series episode "For the World is Hollow and I Have Touched the Sky" a group of aliens have been sequestered inside a large interstellar asteroid for so long that they have forgotten that they are actually inside one.

Music

• "Deth Starr" by Tenacious D is about building a Death Star from Star Wars to explore the galaxy, humanity then goes on to build a million of them.

Podcasts

• Mission to Zyxx goes above and beyond with massive the Planet Crusher, a ship big enough to crush an entire planet.

Radio

• In The BBC's 1980s series Earthsearch the descendants of a starship's original crew, sent to find a habitable planet after the sun threatened to turn nova, arrive back at Earth's solar system 150 years after the ship set out, only to find it gone. Thanks to Time Dilation a million years have passed, and it turns out as their expedition never returned with another planet, humanity developed the technology to move the Earth (surrounded by orbiting artificial suns) to another solar system.

Tabletop Games

• In Pathfinder, Apostae, the tenth planet from Golarion's sun, called "The Messenger", is one of these. It's a Generation Ship, with it's crew/cargo trapped inside, horribly mutated and deformed, having long since lost control of the ship and memory of their mission, if they ever had it to begin with.
  • Starfinder, In addition to Apostae still being around, there is the Brethedan moon of Hibb, a Sleeper Ship that drifted into Bretheda's orbit during the Gap.
• In Warhammer 40,000:
  • Eldar craftworlds are described as "planetoid-sized".
  • The Necron World Engine, unsurprisingly, is a Necron ship the size of a planet (because they slapped an engine on a planet). An entire Space Marine chapter sacrificed itself to give an enormous Imperial fleet a fighting chance.
  • Also, the Phalanx is the moon-sized fortress-monastery-spaceship of the Imperial Fists.
  • The Attack Moons were hollow planetoid ships used by Orks during the War of the Beast. They were created by directly converting the matter of actual planets into the ships, with the same process allowing Attack Moons to repair by stripping planetoids. According to the Eldar, millions of years ago when the Orks were known as Krorks, the achievements of the greenskins put the Beast's later achievements to shame.
  • On a smaller scale, Ork Roks are asteroids and other large celestial bodies that have been hollowed out, filled with Orks, sealed against vacuum, and fitted with ginormous engines to be sent through the Warp. Once close to a planet, they then serve as one-time drop pods.
  • Space Hulks can also fit this definition, though they don't get to the size of planets. Space ships in 40K can be many kilometers long, tall, AND wide. A hulk can be made of hundreds of such ships smashed together. Destroying one with conventional (nuclear bomb-sized) weapons is... difficult to say the least. This is why oftentimes they just drift from place to place, but sometimes the engines on the various wrecks still work well enough to allow limited control.
• World of Synnibarr takes place in a spaceship made from a hollowed out Mars.

Toys

• In BIONICLE, Mata Nui was designed to observe other universes while having beings inside him functioning as Nano Machines in a sense. His Humongous Mecha body is roughly forty million feet (7,575 mi or 12,192 km) tall and had a camouflage system that created an island on his face. Mata Nui was able to control specific things like gravity and light within his body.
• One of these serves as a toy-original form for Primus of the Transformers which can charitably be called a "Battle Station" and more accurately described as just leaving him half-transformed creatively.◊ Seeing as Primus's normal altmode is in fact, an actual Planet, being the inconsistently-sized homeworld of the Transformers, Cybertron, this is a rather literalist example of the trope.

Video Games

• The final stage of Armorines: Project S.W.A.R.M. is set in the main insect Queen's headquarters, a floating spaceship whose interior is a cavernous world infested with monsters. And right in it's core, the final Queen.
• The Jennerit from Battleborn have a massive moon-sized starship called the Exodus which houses the Sustainment Engine and massive power facilities capable of storing energy from other planets like Tempest the Jennerit throneworld for use in Sustainment. Despite its massive size, Exodus is capable of faster-than-light travel and often moves from planet-to-planet to collect vast amounts of energy to power Sustainment procedures. Many of the Sustained and those worthy of being Sustained live aboard Exodus, though some still reside on Tempest.
• The final stage in Descent II takes place in Tycho Brahe, a planetoid geared for spaceflight. The series protagonist notes this while fleeing its death throes:
  "The readings I'm getting on this base aren't consistent with any of the others I've destroyed. It's actually moving, maintaining speed and heading just like a starship."
• Destiny fulfills this trope with Oryx's Dreadnaught: essentially a small pocket universe everted into real space, filling the interior of a spaceship that some rough math places at around 3,500 kilometers long. The Hive put all that extra space◊ to good use◊. The lore also makes reference to Hive "war-moons": whole moons hollowed out and turned into warships, and implies they're busy doing this to our moon.
• Diluvian Ultra takes place in one called Sacrista, where you awake after being entombed for several millenia. Initially you explore the ship's corridors and basements, but later you find out it contains its own forest as well as the ruins of a huge, neo-gothic style city.
• Final Fantasy XIV: Endwalker reveals at the halfway point of its story campaign that Hydaelyn's moon is not only a prison for cotaining Zodiark, but an enormous spacecraft designed for ferrying the inhabitants of the planet to a new home in the event of the Final Days, with a race of benevolent Moon Rabbits operating it and constructing habitats to house an entire planet's worth of refugees. Thankfully, by the end of the story, the need to use the moon to escape a dying world passes, and efforts are resources are instead diverted to turning the moon into a tourist spot for the planet's denizens.
• In the videogame adaptation of Futurama, Mom's plot involves transforming the Earth into a giant spaceship.
• The Xianzhou Alliance in Honkai: Star Rail is a loose confederation of six ancient planet-sized ships whose main goal is to eradicate the undead followers of the Abundance. One of the central story arcs takes place on the Luofu, and is shown to be a bustling and busy world-ship and large enough to contain an entire ocean that seals away the ancient Ambrosial Arbor.
• Kirby:
  • The Access Ark in Kirby: Planet Robobot looks to be nearly as big as Popstar itself in the opening cinematic and on the world map. It's the mothership of the Haltmann Works Company and is used to mechanize and invade planets before stripping them of their resources, though its true nature, a reactivated Galactic Nova, ends up being quite a surprise.
  • In Kirby Star Allies, the third major area in the game is the Jambastion, a colossal fortress that digs itself into Planet Popstar similarly to the Access Ark. It takes up a sizable chunk of the planet on the world map... but it's completely dwarfed by Jambandra Base, which has several Jambastions orbiting around it like moons.
• In Marathon, the eponymous ship was originally Mars' moon Deimos. This is less impressive than it sounds, given that Deimos is about six kilometers long... fairly big by human standards, but nowhere near the size of a planet.
• In Meteos, the inhabitants of Darthvega destroyed their homeworld through war and now live in what looks like an octahedral Death Star.
• The first two games in the Might and Magic series has an implicit case: the worlds they take place on are indicated to be just two out of several carried by an Ancient automated vessel. Both CRON and VARN (the worlds in question) are decently-sized themselves, giving some inkling of the minimal size of the vessel. The third game does not actually take place on this ship, but the islands on planet it does take place on were once smaller such worlds on the ship that were placed on the planet by the Ancients as colonies. On a more minimal scale, the villain of World of Xeen (the combined IV/V) planned to use XEEN as this (the problem is that while it would indeed be entirely possible to do this, it'd kill the natives, at least with the villain's implementation).
• Phantasy Star III has two moons, Azura and Dahlia, which are both artificial satellites to the Alisa-III, one of a fleet of Generation Ships that took off from the planet Palma. Why a spaceship tasked with finding a new homeworld for its inhabitants would require its own satellites is never explained.
• Sonic the Hedgehog:
  • The Death Egg, a parody of the Death Star. The intro of Sonic 3 & Knuckles illustrates just how big it is—the Eggman face fills the top of a volcano (Lava Reef, to be exact).
  • Sonic Adventure 2 features the Space Colony ARK. It looks like a small moon before half of it breaks off to reveal the Eclipse Cannon, and it has enough of a gravitational pull to draw various small asteroids in its orbit. During this and subsequent games, it can occasionally be seen in the sky looking like a second moon.
• Downplayed in Space Tyrant. The Hoplites (a Proud Warrior Race of humanoid rabbits) utilize asteroids to build their ships out of, by hollowing them out and adding computers, comms, engines, and guns. Small ships use small spacerocks, big ships use bigger (or even multiple, as is the case with Cruisers and Battleships) spacerocks. Except for their Destroyers, which mostly use purpose-built hulls (constructed from yellow jade, of all things).
• StarCraft II: Legacy of the Void: The Spear of Adun is 74 kilometers long, but Ulnar, home of the Xel'naga, postively dwarfs it. One of the loading screens features them side by side and while the Spear of Adun looks tiny, most of Ulnar still doesn't fit on the screen.
• In Star Ruler, the players can make ships anywhere from the size of a coke can to ships larger than the galaxy. At around ship scale 1000, ships start to become larger than the planets that build them. Additionally, it's possible to turn entire planets into ships by researching the Planetary Thruster. Building a bunch of planetary thrusters, some shield generators, and planetary laser cannons essentially turns the planet into a ridiculously durable, but relatively poorly armed ship with the capacity to store thousands of smaller ships, or build more ships on the way to its destination by importing goods from the galactic bank.
• The Voth fortress-ship in the Star Trek Online PVE raid "The Breach". Starfleet's Odyssey-class has been scaled as roughly a kilometer in length, and this thing probably dwarfs a hundred Oddys nose-to-stern. Oh, and it carries multiple Citadel-class dreadnoughts within it like fighters, each of them roughly 10 km long. Indeed, the official chart released by the devs when "The Breach" was launch lists it as 134.5 kilometers long. Meaning it can cover the entire San Francisco Bay Area.◊
• The Gigastructural Engineering mod for Stellaris allows one to convert moons into starships... for starters. Later, you can convert barren planets as well, build megastructures that churn out higher quality moon-sized ships (for which you need to reprocess entire planets into materials), and finally, combine half a dozen moons and about as many planets into a huge ship. Then you need to select the planet that would contribute the billions of people required to crew it.
• The Starship Mario serves as the Hub Level in Super Mario Galaxy 2 and flies Mario between galaxies. Though it's a Baby Planet like most of the others in the game. In the previous game, the Hub Level is a massive spaceship that turns into a comet.
• The Grineer Queens' Kuva Fortress in Warframe is a massive asteroid with spaceship engines built into it, allowing the Grineer high command to evade detection and attack from their enemies by constantly relocating their base of operations.
• The X-Universe series' backstory provides an extreme example. Billions of years ago the Ancients fought a several-million-year-long war against a Kardashev Type V+ race called the Outsiders who are believed to have invaded from another universe. They entered ours in the form of several ships that were each the size of a solar system. (Yeah, Sufficiently Advanced Alien doesn't even begin to cover this.)
• XCOM: Enemy Unknown has the alien Temple Ship, which is roughly the size of Greenland. Bonus points for its gravitational pull causing earthquakes when it arrives.
• The Red Moon from Final Fantasy IV, and the True Moon from Final Fantasy IV: The After Years, are both artificial constructs that can move under their own power.
• Xenosaga has several examples:
  • The Dammerung is described in the accompanying Perfect Works manual as an artificial planet the size of Lebanon. It's the headquarters for Fiction 500 company Vector, and contains at least one megalopolis in an area large enough to have a real weather system.
  • The Kukai Foundation's home is another artificial planet.
  • Abel's Ark is an Eldritch Starship the size of an entire solar system. After the Durandal is rammed into it in Episode III, you can actually see what's left of it as a backdrop when you go inside the Ark.

Visual Novels

• Galaxy Angel: The Black and White Moons. In the first game, the Black Moon is shown explicitly to move through space, while the White Moon was assumed dormant and floated above planet Transbaal, until Eternal Lovers where it actually warps towards the borders of the Empire to assist in the war against the Valfasq.
• Marco & the Galaxy Dragon has Astaroth's Planet Crusher, a starship so enormous that it can literally crush a planet in its grip.

Webcomics

• The climax of A Miracle of Science features Mars' moon Deimos being used in this fashion, in this case to provide a credible threat to back up the main characters and get the Big Bad to stand down. It's also a clever use of Exact Words, as Mars is under treaty to never extend military force beyond the orbit of Deimos. If Deimos can move...
• Quentyn Quinn, Space Ranger:
  • One arc takes place on the Sapphire Star, a worldship of the Empire of the Seven Systems with a diameter in the tens of kilometers. It's used as a mid-range luxury cruise liner.
  • The 40K bash arc has the "Hyooman Empiyah" come into the galaxy in a fleet of shipworlds.
• Schlock Mercenary
  • A race of short-sighted robots packed their colonists onto a Colony Ship made from a gas giant. It crashed.
  • A number of Precursor races created World Ship — star-powered vessels so big that they had to be constructed as spheres to keep them from being crushed by their own gravity.
  • The Pa'anuri war ships are the size of planets; one is explicitly described as the size of Jupiter. They exert enough gravity to affect the orbits of natural planets. They make them by murdering World Ships.

Web Original

• Orion's Arm:
  • Fusion candles, essentially gigantic fusion rockets used for moving around planets or even stars. Since they greatly disturb the environment, they're generally used on uninhabited planets.
  • There are several technologies for moving stars, which moves any planets orbiting them as well.
  • The Leviathan, a galaxy spaceship. That is to say, it's the approximate mass of an entire galaxy moving under its own power, with an approximate size of 10 light-years. It is believed to consist of a huge number of Dyson Spheres connected in a giant net-like configuration. It's travelling through dark space from another galaxy cluster and is currently passing through the Triangulum Galaxy. How in the hell someone managed to build something like this, or more importantly, why someone built something like this, is entirely unknown. Fortunately, since FTL travel is not possible in this 'verse, it'll be around 4 million years before anyone in the Milky Way has to worry about this thing...
• The Ship Moves (Or Warhammer 50,000: Age of Exodus), a variation setting based off of Warhammer 40,000 crafted on the /tg/ board of 4chan.
  • It begins with the God-Emperor waking up and giving a set of orders before going back to bed. Said orders result in the creation of The Ship. With a keel of approximately One Astronomical Unit in length (1 AU = 149597871 kilometres, by definition the distance from the earth to the sun), the remains of the Imperium stripped to build it, Holy Terra itself hollowed out and fitted with cogitators and command system and the Imperial Palace itself becoming the bridge and God-Captain of Humanity guiding it.
    The Ship is the Imperium.
    The Imperium is the Ship.
    The Ship is the Emperor.
    The Emperor is the Ship.
    All is the Ship.
    The Ship is All.
    The Ship Moves.

Western Animation

• Mission Control in Captain Star is described as "the largest object in Creation" and resembles a planet when briefly shown.
• In Invader Zim, the original inhabitants of Mars drove themselves to extinction converting their planet into a giant spaceship... "Because it's cool". A similar thing happened to Mercury, which leads to an awesome dogfight.
• Shadow Raiders feature a handful of planets with engines designed by an unknown precursor race. In fact, the toyline it's loosely based on was called "War Planets".
• She-Ra and the Princesses of Power: During her research into the First Ones tech, Entrapta finds out that Etheria is not a natural planet but in fact a planet-sized space ship.
• Unicron, the planet-sized, planet-shaped planet-eating Big Bad from the Transformers Movie and later incarnations is capable of moving around at a significant clip in either Planet or Robot mode, qualifying him for this trope.
• The Vedala of Star Trek: The Animated Series, who are the oldest space-faring race in existence, travel the cosmos on planetoids terra-formed and refitted to be mobile.

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