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This article is for the PC version of Stellaris only.
This article is for the PC version of Stellaris only.
A celestial body is a named object (such as a planet or large asteroid) occurring within a star system. Celestial bodies may have resources which can be harvested by orbital stations. Planets may also be habitable and capable to be colonized by empires with the right suitability or technology.
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, surface tiles and their resources, and the habitability percentage for each species in the player's empire. Additionally, surveying worlds has a chance to reveal anomalies.
Summary of celestial body types
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 9 habitable worlds are divided equally into 3 climate categories: dry, frozen and wet.
- Special habitable worlds
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.
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.
|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.||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.|
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.
|Class B||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||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||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||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||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||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||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||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||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.
|Black Hole||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.
|Neutron Star||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.
Habitability is the measure of how well a species can live on a planet. Every species has a climate preference for one of the primary habitable world types. A planet's habitability (and terraforming cost) is determined by its climate. The 9 habitable worlds are divided into 3 climate categories: dry, frozen and wet. Gaia worlds and Megastructures have maximum habitability for all species while Tomb Worlds and Machine Worlds are normally uninhabitable by biological species.
|Gaia, Megastructures and Ecumenopolis||100%|
|Tomb World and Machine World||0%|
Worlds of any type may have features which either increase or decrease their habitability. If present, these features will be identified when the world is surveyed by a science ship.
- Every 1% of Habitability under 100% increases the Pop Upkeep and Amenity Usage by 1% and their resource output and happiness by 0.25%. It caps at 0% Habitability, giving +100% Pop Upkeep and Amenity Usage.
- Homeworlds have a +30% habitability for the species originating on them.
- Low Habitability can also trigger events.
Terraforming allows the change of the Climate class to be one more suitable for the intended Colonists. However, the process is very costly, requires decades of time and requires special technology if it is not only from a secondary to the primary habitability. This step can now be done retroactively on an already colonised planet, once the relevant tech has been researched. However, during Terraforming, Pops will suffer −20% to their happiness.
Using genetic modification, one can create a subspecies of the empires primary species that is suitable for the Climate in question. However, this needs either the first-in approach (so they can be changed on the new Planet) or a staging area with increased Habitability regardless of current Climate Preference (Ringworld, Habitat, Homeworld, rare modifiers).
Changing a habitability trait now cost the equivalent of adding a trait worth 3 trait-points. The relevant tech must also be researched before the habitability trait can be changed.
With all the possible habitability types, there are bound to be some aliens that can live comfortably on planets which are unsuitable to the primary species. The main disadvantage is that xeno pops have increased Unity cost per pop and might not have favorable traits. There may also be unwanted Xenophile attraction/Faction interactions from this path.
Both via Conquest and Migration Treaties, one can add xeno pops to the Empire to use as colonists. If the empire is Xenophobe, the rights limitations for xenos will make the pops also considerably less happy. The migration approach requires a "first-in" colonist.
Genetic Uplifting, Enlightenment and Infiltration can be used to acquire a xeno species as well. With the first one, it might even be possible to get a rare Habitability like Tomb Worlds. Very rare species native to Tomb Worlds are extremely adaptive and can thrive on any kind of planet (every normal class is secondary). The usual way of obtaining these species as subjects is finding them as upliftable semi-sentients on Tomb Worlds and uplifting. The event chain Horizon Signal can also create a subspecies of your main species with this trait. Alternatively, pops of your main species on Tomb Worlds may mutate and develop into their own species native to Tomb Worlds.
All robots, including the primary species of Machine Intelligence empires, have 100% Habitability on every kind of inhabitable world. However, only drones and synthetics can actually be colonists. Synthetics are good to superior in all tasks, but also increase the Unity costs. Robot pops furthermore have a massive draw towards Materialist ethics, both for themselves and other pops on the planet.
While the initial growth might be slower than a pure biological species, once the pop count is sufficient, Robots will also grow a lot quicker than biological species. Droids or synths make particularly good "first in" colonists, if they can be moved off or Materialist attraction is acceptable.
Systems containing surveyed or non-surveyed habitable worlds will have one or more planet icons that are either green, yellow, orange, red, or blue, depending on the habitability percentage and/or status of the planet(s) in question.
- Green: The world is ≥70% habitable for at least one species in the player's empire.
- Yellow: The world is 40–69% habitable for at least one species in the player's empire.
- Red: The world is <40% habitable for all species in the player's empire.
- Orange: The world is habitable but not surveyed.
- Blue: The world is currently being Terraformed.
Sometimes other factors can prevent colonization of a world. Some common reasons for not being able to colonize an otherwise habitable world are:
- There is an anomaly on the world which has not yet been researched
- The world is inhabited by a pre-FTL civilization
Zooming in to the system and hovering over the planet icon may reveal useful information about what is preventing the player's empire from colonizing the world. e.g. If the tool tip says the world is 'controlled by Unidentified Empire' or 'belongs to someone else', another empire is in control of the system. In this case, surveying the world will reveal the empire that controls it. This action can cause the player's science ship to be missing in action for up to a year, so it may be preferable to avoid surveying the world.
Since different species can have different world type preferences, it can be better for an empire to populate its worlds with other alien species, genetically-engineered subspecies, or even robots/synthetics.
It is also possible to terraform habitable worlds, though this is a costly and time consuming process. Only planets of the main types (continental and such) can be terraformed, in addition to tomb and barren worlds with the "Terraforming Candidate" modifier.
All planets have a random number of Planetary Features, which determine the number of Districts and Strategic Resource extraction buildings a world can support. Certain features are more likely to appear depending on the planet class.
|Agriculture Districts||Generator Districts||Mining Districts||Crystal Mines||Gas Extraction Wells||Mote Harvesting Traps||Betharian Power Plant||Alien Zoo|
These Rare Planetary Features are added by random anomalies on habitable planets.
These Rare Planetary Features are added by certain events.
A number of unique planets in the galaxy come with special Planetary Features.
Earth will always feature 9 unique Planetary Features instead of randomized ones. Their description also reveals part of humanity's history before the events of Stellaris.
Blockers are obstacles that block Planetary Features. Until a Blocker is cleared the obstructed Planetary Feature cannot be exploited. Each also reduces the maximum number of Districts on the planet by 1 or more, so they are worth clearing even if the extra possible districts are never built. Blockers can be cleared for a modest cost in minerals, energy, and time, if the player has researched the required technology. There are 9 such technologies, one for every normal blocker type, and they are all relatively easy to research. All normal blockers cost the same amount of resources to remove.
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.