Celestial body

Version

This article is considered accurate for the current version (2.3) of the game.

Celestial body

Classification

Colonization

Terraforming

Planetary features

Modifiers

A celestial body is a star, planet, moon or asteroid present in a star system. Celestial bodies may have resources which can be harvested by orbital stations. Each start system can have between 2 and 15 celestial bodies.

When any owned ship enters a system or passes within its sensor range, any habitable planets in the system will be revealed along with their world type. To see further details about the celestial bodies in a system, it is necessary to survey them with a science ship. This will reveal all of the orbital resources associated with each planet or asteroid. For habitable worlds this will also reveal more detailed world information including: size, available districts, blockers (if any), special features, and the habitability percentage for each species in the player's empire. Additionally, surveying worlds has a chance to reveal anomalies.

Classification

Habitable worlds

For the various specialized colony types, see Planetary management § Designation.

A habitable world is any celestial body that can harbor advanced organic life. These are the only worlds that can be colonized and terraformed, besides some notable exceptions. Their suitability ranges in accordance to a given species' homeworld, which affects the rate of population growth.

A planet's habitability (and subsequent future terraforming costs) is determined by its climate system. The nine habitable worlds are divided equally into three climate categories: dry, frozen and wet.

	Type	Climate	Description
	Arid	Dry	Dry, rocky world with a nitrogen-oxygen atmosphere. The dust-covered terrain consists largely of mesas and canyons. Forests can be found in the more temperate polar regions, but vegetation is otherwise scarce.
	Desert	Dry	Dry, rocky world with a nitrogen-oxygen atmosphere. Precipitation and major bodies of surface water are relatively rare. Significant temperature variations between day and night cycles. Vegetation is scarce, but even moderate precipitation can make the desert bloom.
	Savanna	Dry	Rocky world dominated by dry, arid plains covered by a nitrogen-oxygen atmosphere. The small hydrosphere allows for brief wet seasons, but aside from a few ubiquitous grasses vegetation is largely concentrated around shallow oases.
	Alpine	Frozen	Mountainous world with a nitrogen-oxygen atmosphere. Snow covers the mountaintops and frozen-over lakes dot the valleys. While the planet experiences the minimal seasonal variations, the still-liquid water beneath the frozen surface of the lakes is enough to sustain some hardy vegetation.
	Arctic	Frozen	Frigid, rocky world with a nitrogen-oxygen atmosphere. The poles are big, and significant water deposits can be found permanently frozen as glacial ice. However, the planet experiences seasonal variations and the equatorial band is covered by vegetation.
	Tundra	Frozen	Cold and rocky world with a nitrogen-oxygen atmosphere. Permafrost covers most of the surface except for the more temperate equatorial regions. A stable biosphere exists but vegetation is mostly limited to mosses and lichens.
	Continental	Wet	Rocky world with a nitrogen-oxygen atmosphere. Active and stable hydrosphere. Great landmasses are separated by oceans, with large climate variations depending on latitude and precipitation.
	Ocean	Wet	Rocky world with a nitrogen-oxygen atmosphere and a significant hydrosphere. Oceans cover more than 90% of the surface, with scattered islands making up the remaining percentage.
	Tropical	Wet	Humid, rocky world with a thick nitrogen-oxygen atmosphere. Seasons with significant precipitation are interchanged with drier periods. Most landmasses are covered in dense vegetation.

Special habitable worlds

	Type	Terraforming requirements	Pop effects	Notes
	Gaia	World Shaper ascension perk Nu-Baol Life-Seeding decision Cannot be terraformed again	100% Habitability +10% Biological Pop Happiness +10% Resources from Jobs	The number of pre-generated Gaia worlds is limited. The home systems of three of the Fallen Empires contain Gaia worlds. A size 25 Gaia world called Zannam will occasionally spawn in a galaxy. It is defended by the Guardians of Zanaam. Four Gaia worlds with special names - Prophets Retreat, Walled Garden, Emerald Mausoleum, Pristine Jewel - border the systems of the Holy Guardians. They have the Holy World modifier and colonizing them will incur their ire. Destroying them will even awaken the Fallen Empire. Empires with the Life-Seeded civic will start on a Size 25 Gaia world. Their species' climate preference will also be changed to Gaia World. A Gaia world is located in the Sealed Wormhole system and requires defeating the Corrupted Avatar to claim the system. One of the outcomes of the Stellarite Devourer event chain will turn a frozen planet in its home system into a Gaia world. A system containing a size 25 Gaia world called Paridayda can be spawned as part of the Paradise Lost event. It has no natural resources but comes with a unique planet modifier granting various bonuses. A Gaia can be found in a special binary system. Every 3 months it changes between Gaia and Shrouded but claiming the system will allow the creation of a Special Project to permanently set the planet to a Gaia world.
	Tomb	Armageddon bombardment Javorian Pox bombardment	0% Habitability	Tomb Worlds are habitable but feature the poorest base habitability and very few Planetary Features. Also, a species cannot be gene-modified to suit a Tomb World. Pre-FTL civilizations in the Atomic or Early Space Age have a small chance of starting a nuclear war and turning the planet into a Tomb World. Empires with the Post-Apocalyptic civic start on a Tomb World and get the Survivor trait, granting them +70% Tomb World Habitability as well as +10 Years Leader Lifespan. Empires with the Determined Exterminator civic start on a Tomb World as well. Colonizing a Tomb World will displease the Traditionalist faction, unless the empire has the Post-Apocalyptic civic.
	Ecumenopolis	Arcology Project decision Restore Ecumenopolis decision Cannot be terraformed again	100% Habitability +20% Resources from Jobs +50% Pop Growth speed	The only pre-existing ecumenopolis is the homeworld of the Keepers of Knowledge Fallen Empire All normal planetary features are removed. Planetary Prospecting decision disabled. These city planets have their own set of districts that focus on providing massive amounts of Housing and refining basic resources. The city lights of an Ecumenopolis World are determined by the ship appearance of the terraforming empire. Empires that are Gestalt Consciousnesses or have the Agrarian Idyll civic cannot take the ascension perk but can still use conquered Ecumenopolis Worlds. Requires the Megacorp DLC.
	Relic		80% Habitability	Relic Worlds can be found in the First League precursors home system or in various systems added in the Ancient Relics DLC. Relic Worlds contain unique Planetary Features that grant bonuses to Research output. However most of the surface is covered by Blockers that are expensive to remove. Relic Worlds have the aforementioned Restore Ecumenopolis decision available. It terraforms the planet into an Ecumenopolis but loses its Planetary Features. If an Archeological site was present and not fully excavated it will be lost.
	Hive	Hive Worlds ascension perk	100% Habitability if Hive-Minded 0% Habitability if not Hive-Minded +10% Resources from Jobs	All normal planetary features are removed. Number of resource districts no longer limited by features. Planetary Prospecting decision disabled.
	Machine	Machine Worlds ascension perk	100% Habitability if Mechanical 0% Habitability if not Mechanical +10% Resources from Jobs	All normal planetary features are removed. Number of resource districts no longer limited by features. Planetary Prospecting decision disabled. Cannot support Agriculture Districts. The following planetary modifiers will also be removed: Atmospheric Aphrodisiac, Atmospheric Hallucinogen, Bleak, Hazardous Weather, Hostile Fauna, Irradiated, Lush, Natural Beauty, and Wild Storms.

Uninhabitable celestial bodies

All non-star celestial bodies that cannot harbor advanced organic life are classified as uninhabitable. These worlds can't be colonized or terraformed, but can still be lucrative sources of common and strategic resources.

	Type	Potential Common Resources	Potential Strategic Resources	Description
	Asteroid	Minerals	Volatile Motes	A larger asteroid or planetoid standing out in the dense cluster of smaller bodies.
	Ice Asteroid	Minerals	Rare Crystals	A larger asteroid or planetoid composed primarily of frozen H2O.
	Crystalline Asteroid	Minerals	Volatile Motes?	A large asteroid covered in some kind of crystalline outcroppings. May contain Asteroid Hives
	Barren World	Minerals Physics Research		Barren and rocky world with a thin or non-existent atmosphere. The surface is covered in meteor impact craters and completely devoid of life. Can be terraformed if terraforming candidate modifier exists
	Barren World (Cold)	Minerals Physics Research		Barren and rocky world with a thin or non-existent atmosphere. The surface is covered in meteor impact craters and completely devoid of life. Can be terraformed if terraforming candidate modifier exists
	Frozen World	Minerals Engineering Research	Rare Crystals	Rocky world covered in a thick layer of permanently frozen ice. Low temperatures and a very thin atmosphere precludes the existence of life on the surface.
	Gas Giant	Energy Engineering Research	Exotic Gases Zro	Gaseous planet with an atmosphere primarily composed of hydrogen and helium surrounding a dense core.
	Molten World	Energy Minerals Engineering Research	Volatile Motes	Rocky world that is scorching hot. The atmosphere is thin or non-existent, and lava from the interior flows freely due to constant volcanic eruptions. This type of planet cannot sustain organic life.
	Toxic World	Minerals Society Research	Exotic Gases Zro	A rocky planet with a thick atmosphere that is lethal to all known higher forms of life.

Special worlds

A special world is any celestial body that does not follow the standard rules of procedural generation and are, in many cases, only created by events.

	Type	Notes	Description
	AI	These planets are created by the Contingency. They are similar in appearance to Machine worlds, but are not habitable at all. Successful bombardment turns the planet into a broken world.	Rocky world covered with artificial structures. The thin atmosphere consists mostly of industrial pollutants. There are strong energy emissions coming from across the entire surface, but no organic life signs.
	Broken	Rare planets that are as useless as they are broken. Often spawn in Black Hole systems.	World devastated by some cataclysmic event. Whatever properties it may once have had are no longer discernible.
	Cracked	Created by the hatching of the Voidspawn, destroying the existing colony. Has a deposit of 20 Society.	The cracked shards of an enormous planet-sized egg.
	Infested	Created when habitable worlds are infested by the Prethoryn Swarm. Successful bombardment turns the planet into a barren world that can be terraformed.	The surface of this world is covered by some kind of biological contaminant.
	Nanite	Found in the L-Cluster, with half of the outcomes giving them the Terraforming Candidate modifier once the nanite factory is destroyed.	A chaotic and inhospitable world, disfigured according to some mad design.
	Shattered	Created when a planet is destroyed with a World Cracker. The Shattered world will get a deposit of between 4 and 16 Minerals.	The charred, broken remnants of what was once a planet. A massive energy surge has detonated this world's core, leaving only slabs of rock.
	Shielded	Found inside Militant Isolationists Fallen Empire territory. The shield can be brought down through a special project, with different possible outcomes (mothballed fallen empire ships, a captive admiral or a group of Void Clouds). They can also be created using the Global Pacifier Colossus weapon, but these worlds cannot then be un-shielded.	This entire world is encased in some kind of impenetrable energy barrier. It blocks all scans of the surface.
	Shrouded	Created by the End of the Cycle or when the Eater of Worlds is ravenous. Cannot be recovered. A few shrouded world can be found in some special systems.	Our sensors are unable to penetrate the thick fog surrounding the planet. Ships that enter it do not return.

Habitable Megastructures

Habitable Megastructures are entirely artificial. They feature the same habitability for every species, have unique Districts and have no colonization cost as long as they are within borders.

Type	Size	Notes	Description
Habitat	6	Requires the Habitat technology Has 3 types of Districts, with a fourth one being available if build over a planet with a resource deposit	An artificial deep-space arcology offering planet-like, if decidedly urban, living conditions. Hydroponics and advanced filtering technologies make it near-self-sustaining, and station-borne facilities can mine the station's host planet for raw materials.
Ring World	5	Ring World districts, called segments, typically have +20 free Housing Intact Ring Worlds are found only in the the Sanctuary system and the Ancient Caretakers home system. Can be repaired from broken segments with the Mega-Engineering technology Can be built in uninhabited systems after taking the Galactic Wonders ascension perk Segments destroyed by a crisis or World Cracker cannot be repaired	An immense band encircling the system's sun. Built to allow for numerous artificial habitation zones along its inner span, freed from the restrictions and mundanity of planet-bound, spherical existence.

Stars

A star is a celestial body that composes the center of a star system and influences the generation of the solar system. They are classified based on their spectral characteristics. Less common stars also have a negative effect on all ships in the system, making certain tactics less effective in battle.

Most systems have only one star but a few have two or three stars, either orbiting each other with the planets around them or far enough from each other that a few planets orbit each star.

	Type	Potential Resources	Description
	Class B	Energy Physics	The large class B main-sequence stars are very bright and blue. Although somewhat rare, the luminosity of these stars make them among the most visible to the naked eye.
	Class A	Energy Physics	These relatively young white or bluish-white main-sequence stars are typically among the most visible to the naked eye. They are large and rotate very quickly, but will eventually evolve into slower and cooler red giants.
	Class F	Energy Physics	F-type stars are fairly large and often referred to as yellow-white dwarves. Although they often emit significant amounts of UV radiation, their wide habitable zones have a good chance of supporting life-bearing worlds.
	Class G	Energy Physics	Often referred to as yellow dwarves, G-type stars actually range in color from white to slightly yellow. Main-sequence stars fuse hydrogen for roughly 10 billion years before they expand and become red giants. Although their lifespans are shorter than K-type stars, worlds inside the habitable zone of a G star often enjoy optimal conditions for the development of life.
	Class K	Energy Physics	These main-sequence stars, sometimes referred to as orange dwarves, are a fairly common sight. They are stable on the main-sequence for up to 30 billion years, meaning that worlds orbiting a K-type star have a longer than average window to evolve life.
	Class M	Energy Physics	The most common stars in the universe, often referred to as red dwarves. Their low luminosity means they are difficult to observe with the naked eye from afar. Although they typically have an extremely long lifespan, red dwarves emit almost no UV light resulting in unfavorable conditions for most forms of life.
	Class M Red Giant	Energy Physics	With a large radius and comparatively low surface temperature, red giants are stars of moderate mass in a late stage of stellar evolution. Their expanded stellar atmosphere and high luminosity make for distant habitable zone orbits.
	Class T Brown Dwarf	Energy Physics	Brown dwarfs are substellar objects that lack the mass to sustain hydrogen fusion. Roughly the size of large gas giants, they have a much greater density. Their low luminosity and comparatively small heat generation means that planets orbiting them are unlikely to support life.
	Pulsar	Engineering Physics	Pulsars are highly magnetized neutron stars that emit beams of electromagnetic radiation. As the star rotates, the radiation beam is only visible when it is pointing directly at the observer. This results in a very precise interval of pulses, which sometimes is so exact that it can be used to measure the passage of time with extreme accuracy. The radiation emitted by pulsars interferes with deflector technology, rendering ship and station shields inoperable. +100% Shield Nullification
	Black Hole	Engineering Physics Dark Matter	Typically formed as a result of the collapse of a very massive star at the end of its life cycle, black holes have extremely strong gravity fields that prevent anything - including light - from escaping once the event horizon has been crossed. The gravitational waves emitted by black holes interfere with FTL drives, making it harder for ships to escape from combat. +50% Disengagement Chance Reduction +50% Emergency FTL Jump Cooldown Allows starbases to construct the Black Hole Observatory building.
	Neutron Star	Engineering Physics	These incredibly dense stellar remnants are sometimes created when a massive star suffers a rapid collapse and explodes in a supernova. Although their diameter is typically as little as ten kilometers, their mass is many times greater than an average G-type star. The gravitational waves and radiation emitted by Neutron Stars must be carefully navigated around, slowing the sublight speed of ships. +50% Sublight Speed Reduction

Celestial body modifiers

There is a small chance that a celestial body will have one or more modifiers. They will be found when surveyed or through anomalies and accompanying events.

	Modifier	Effects	Spawn chance	Removed by terraforming	Description
	Bleak	−5% Habitability −10% Food from Jobs −2 Max Agriculture Districts	x0 if Tropical x0 if Lush	Yes	Life struggles to survive here, and while some clings to a tenacious existence it is anemic and sickly.
	Irradiated	−10% Habitability −20% Biological Happiness −50% Food from Jobs −6 Max Agriculture Districts +2 Max Mining Districts		Yes	Some long-ago calamity rendered this planet rather heavily irradiated.
	Poor Quality Minerals	−25% Minerals from Jobs −3 Max Mining Districts	x4 if Low Gravity x0 if Carbon World	No	It is unknown if this planet simply formed this way, or if some unknown race once stripped it of its more valuable resources. However, we do know that the minerals present on this planet are of unusally poor quality.
	Tidal Locked	−30% Max Districts	x3 if moon	No	This world is tidally locked around its star, meaning that one side always has daylight while the other is locked in eternal darkness. If life exists here, it is likely limited to the twilight regions where the two sides meet.
	Unstable Tectonics	−10% Habitability −5% Happiness +20% Engineering from Jobs	x4 if High Gravity	No	This world has very unstable plate tectonics and is prone to massive earthquakes and volcanic activity.
	Weak Magnetic Field	−5% Habitability −5% Pop Growth speed	x2 if Low Gravity x0 if Strong Magnetic Field	No	Although habitable, this world has a weak or non-existent magnetic field that offers little protection against cosmic radiation.
	Asteroid Impacts	−5% Habitability +5% Minerals from Jobs +2 Max Mining Districts		No	The orbital path this world takes around its star is littered with small asteroids, meteors, and comet swarms. Large impacts on the surface occur at an alarming frequency.
	Atmospheric Hallucinogen	+5% Biological Pop Happiness +10% Physics from Jobs −30% Government Ethics Attraction		Machine World Hive world	The air of this planet contains a natural hallucinogen. While this does keep people happy, and indeed seems to aid the visualization of some of the more esoteric Physics problems, it also distracts people from other work.
	Hazardous Weather	−10% Habitability −5% Happiness +20% Energy from Jobs +4 Max Generator Districts		Yes	This world suffers from unstable weather patterns, with violent storms frequently appearing out of nowhere to wreak havoc on the surface.
	Hostile Fauna	−10% Habitability −5% Happiness +20% Society From Jobs	x2 if Lush x2 if High Gravity x2 if Titanic Life	Yes	This world has evolved extremely Hostile Fauna, and the surface is rife with lethal predators waiting to ambush their next meal. Their biology offers great research opportunities, however.
	High Gravity	+10% Building cost +10% District cost −5% Habitability +2 Max Districts	x2 if Planet Size > 19 x0 if Planet Size < 12 x0 if Low Gravity	No	This planet is unusually dense and so has uncomfortably high gravity.
	Low Gravity	−10% Building cost −5% Habitability	x0.5 if Planet Size >19 x0 if High Gravity	No	This planet has an unusually low density and therefore much lower gravity than most planets of comparable size.
	Wild Storms	−5% Habitability −5% Happiness +20% Physics from Jobs		Yes	Spectacular electrical storms wrack this planet's atmosphere on a semi-regular basis.
	Asteroid Belt	+10% Minerals from Jobs +3 Max Mining Districts	x0 if moon x2 if Low Gravity	No	Perhaps this planet once had a moon which was destroyed in some calamity, or perhaps its orbital debris never fully coalesced in the first place. Whatever the cause, this planet is surrounded by a belt of small asteroids.
	Atmospheric Aphrodisiac	+5% Habitability +10% Pop Growth speed −20% Government ethics attraction		Machine World Hive world	Something in the air of this planet seems to put people in the mood to reproduce.
	Carbon World	+15% Minerals from Jobs	x0 if not Barren	No	This world has been formed mostly out of carbon, and contains little oxygen.
	Exceptional Quality Minerals	+25% Minerals from Jobs +8 Max Mining Districts	x8 if High Gravity x0 if Carbon World	No	The exceptional quality of the minerals in this planet's crust provides a truly staggering opportunity for mining.
	Extensive Moon System	+10% Minerals from Jobs +1 Max Mining Districts	x0 if not Gas Giant x0 if no moons	No	This gas giant has an unusually large amount of natural satellites. Hundreds of small moons and moonlets orbit the planet.
	High Quality Minerals	+15% Minerals from Jobs +4 Max Mining Districts	x4 if High Gravity x0 if Carbon World	No	An abundance of high quality minerals in this planet's crust makes mining here a lucrative business.
	Lush	+10% Habitability +20% Food from Jobs +4 Max Agriculture Districts	x3 if Gaia x2 if Low Gravity x0 if Bleak	Machine World Hive world	Life thrives here, the fauna is plentiful and the flora grows rapidly.
	Natural Beauty	+5% Happiness +25% Migration Pull	x3 if Gaia	Machine World Hive world	The scenery on this planet is simply beautiful, anyone living on this planet will be constantly finding new wonders to behold.
	Strong Magnetic Field	+5% Energy from Jobs +5% Physics from Jobs +2 Max Generator Districts	x2 if High Gravity x0 if Weak Magnetic Field	No	This planet has an abnormally high magnetic field. This will interfere with many of our instruments and computers.
	Titanic Life	+25% Society from Jobs	x8 if High Gravity x0.5 if Low Gravity x0 if Hostile Fauna	No	The lifeforms of this planet are built on a massive scale and can be incredibly dangerous even without meaning any harm.
	Terraforming Candidate	Can be terraformed	Barren World anomaly Worlds made Barren by a crisis Always present on Mars	Yes	Though barren and devoid of life, this planet has water in frozen form and may once have been home to a thriving ecosystem. With the right technology, it could be terraformed into a habitable world.
	Holy World	−200 Opinion with FE if colonized	Prophets Retreat Walled Garden Emerald Mausoleum Pristine Jewel	No	The planet is considered sacred by a nearby Fallen Empire. Colonizing it will anger them greatly.
	Paridayda	+10% Happiness +10% Unity from Jobs +20% Food from Jobs +25% Migration Pull	Unique to the Gaia world Paridayda	No	A paradiasaical world of unparalleled beauty.

Event Modifiers

These planet modifiers can only be added by events.

	Modifier	Effects	Event	Description
	Subterranean Civilization	+10% Society from Jobs	Seismic Disturbances (Establish Communications Special Project)	A subterranean alien civilization on this world enjoys a good relationship with the colonists on the surface, and both parties frequently engage in trade and cultural exchanges.
	Subterranean Cities	+3 Max Districts	Seismic Disturbances (Preemptive Strike Special Project)	A indigenous subterranean civilization that once lived on this world has been exterminated, and colonists are now free to expand into their abandoned underground cities.
	Ancient Terraforming	+20% Pop Growth Speed	Abandoned Terraforming Equipment (Resume Process Special Project)	Ancient terraforming techniques have turned this world into a lush paradise.
	Abandoned Terraforming Project	-20% Food from Jobs -10% Happiness	Abandoned Terraforming Equipment (Dismantle Equipment Special Project)	This world was partially terraformed thousands of years ago, but the process was interrupted for unknown reasons. The result is a highly unstable climate system and biosphere.
	Surviving Infrastructure	-25% District Cost	Surviving Infrastructure	There is still a significant amount of infrastructure left on this world, built by its original inhabitants before they destroyed themselves in a nuclear war. This will aid in the construction of new buildings.
	Loop Temple Visitor Center	+5% Happiness	The Loop Temple: Time and Stone	Cheery, efficient staff guided tours past primordial sigils bright under floodlights and marked with helpful plaques.
	Loop Temple Pilgirms' Way	+10% Happiness	The Loop Temple: Time and Stone Spiritualist option	Once again, the basalt arches whisper with the hushing of feet and the echo of prayers.
	Superflare Shielding	+10% Unity from Jobs	Superflare (Superflare Shielding special project)	This planet's populace is shielded from the harmful effects of it's sun's superflare activity.
	C.A.R.E. Interactive Interface	+10% Energy from Jobs	C.A.R.E. (Develop A Cure For The Ferrophage special project)	The ancient C.A.R.E. Interactive Interface is working at full capacity on this planet - with some modern improvements, of course.

Anomaly Modifiers

These planet modifiers can only be added by random anomalies.

	Modifier	Effects	Description
	Ancient Harvesters	+20% Food from Jobs	Ancient solar-powered harvesters assist in gathering the planet's crops
	Dead god	+200% Spiritualist Ethics Attraction	The corpse of some gargantuan alien creature keeps silent vigil in orbit over this planet.
	Resonant Crystals	+33% Governing Ethics Attraction +10% Happiness	The resonant crystals that line this planet's tectonic crust resonate at a medically therapeutic frequency for our species.
	Soothing Magnetism	+50% Unity from Jobs	This planet's magnetosphere resonates at a frequency very conductive to our neural network.

References

Game concepts