Planet

NOTICE: This page is a Work in Progress as much of the lore/Development for the game is yet to be established.

A planet is a spherical body found in space. They are often characterised as bodies of gravity which form spherical bodies from materials, varying from gases, solid rock or even ice. Planet types and characteristics often depend on their spawning location and other factors, such as the whether they are within the Habitable Zone. Although their size varies, planets are often smaller than the smallest star types.

Generation

Planets are generated using the Galaxy Generation mechanic. They often form within the vicinity of star systems and once a Long Range survey is performed on a system. Most planets will not be identified until a Medium Range survey is performed. Those which form generate in the Habitable Zone have a chance of generating both life and tech signatures, with will appear after the former is performed.

Generation Process

Planets that generate in a star system are created using real-world data such as the Roche limit and Titius-Bode Law. When star systems are generated, the Galaxy Generation system calculates pro-planetary disks in place of planets, which calculates the star's material composite (H/He/Metals), lifespan and hill sphere. Using the Titius-Bode law, the planets' orbit around the star will be determined. Planets will generally spawn between the star and the Kuiper Belt equivalent for the system.

After each potential planet is determined, planets are generated on core mass accretion, which determines the planet type based on potential escape velocity against H2 thermal velocity. Physical characteristics are then generated, including atmospheric composition and the final Planet Type classification. If the planet orbits a star in its Habitable Zone and if characteristics are possible to sustain life on its surface, Life and Tech Signatures will likely generate on a planet. Once the planet is spawned, its mass is deducted from the proto-disk to ensure there are no copies.

Sensor Data

Using the Sensors Station, starships can gather information on a planet's characteristics. These are generated/gathered by performing surveys on the planet surfaces. By default, the planet appears on the survey as an unknown celestial body with only its orbital data gathered. Characteristics and descriptions are updated as various surveys are performed.

By default, the sensors will gather information about the planet's orbital data in the star system, often around the star in the system. However, performing a Level 1 survey on the planet will gather information about its Physical Characteristics and an estimation of the planet type (Terrestrial, [Gas] Giant or Dwarf). As more surveys are performed, more data is gathered, including on any civilisations that habit the planet.

The following table presents the sensor data for planets and the sensors level/array used to gather it from them:

Survey Level	Range	Array	Data Gathered
0	Default Overview	SCMI Array	Overview A brief description of the planet. These will be updated as higher level surveys performed on it. Orbital Characteristics Roche Limit Hill Radius Semi-Major Axis Semi-Minor Axis Apoapsis Periapsis Average Distance Eccentricity Inclination Orbital Period Orbital Velocity
1	Long Range	SCMI Array	Physical Characteristics Age Mass Density Radius Volume Gravity Escape Velocity Equilibrium temperature
2	Medium Range	MBIS Array	Atmosphere Data Atmosphere Average Temperature Hydrogen Helium Methane
3	Short Range	SATIR Array	Surface Data Coming Soon Civilisation Data Civilisation Name Physiology Government Religion Tech Level Aggression Xenophobia

Planet Types

Terrestrial Planets

Terrestrial planets are composed primarily of rocks and solid materials such as metals. They often consist of a core and multiple material layers. Some terrestrial planets spawn with liquid environments or with molten substances on their surfaces, such as Earth-like Analogues or Lava Planets. Some also spawn with gases like ozone in their atmosphere, with some becoming Earth-like analogues capable of supporting life itself.

Atmospheric Terrestrials

• Characteristics: Rocky surfaces and atmospheres, though often lack liquid surfaces like water or lava.
• Examples: Mercury, Venus, Mars
• Notes: Will often spawn in or outside the Habitable Zone, often between the Lava Zone and the Frost Line

Lava Planets

• Characteristics: Rocky surfaces and atmospheres with molten materials on their surfaces.
• Examples:
• Notes: Will often spawn in the Lava Zone in a star system's orbit.

Earth-like Analogues

• Characteristics: Rocky surfaces and atmospheric, with the surface being able to support life and generate water on their surface.
• Examples: Earth
• Notes: Will often spawn within the habitable zone of certain stars, such as G and K class stars

Giant Planets

Giant planets are a term given to planets which exceed Earth's size. Gas Giants are often composed of light materials and gases, often Hydrogen or Helium. There are five classifications depending on their atmospheric properties. However, Ice Giants consist of frozen materials on their surface. By default, long range sensors will recognise any giant planet as a gas giant until a medium range survey is performed. Examples of giant planets include Jupiter, Saturn, Neptune and Uranus.

Class I Gas Giants

• Characteristics: The planet's temperature does not exceed 150 K and atmosphere primarily consists of the chemical ammonia clouds.
• Examples: Jupiter, Saturn
• Notes: Can currently spawn outside of a star's frost line, due to the volatile nature of the planet's content.

Class II Gas Giants

• Characteristics: The planet's temperature does not exceed 250 K and atmosphere primarily consists of water ice clouds.
• Examples: Epsilon Eridani b, Upsilon Andromedae d (both speculated)
• Notes: Can currently spawn outside of a star's frost line, due to the volatile nature of the planet's content.

Class III Gas Giants

• Characteristics: The planet's temperature is between 350 to 800 K and its atmosphere is unable to form clouds due to the lack of chemicals on the atmosphere capable of forming them.
• Examples: Upsilon Andromedae c, Gliese 876 b (both speculated)
• Notes: Can currently spawn between the lava zone and frost line.

Class IV Gas Giants

• Characteristics: The planet's temperature exceeds 900 K and alkali metals can be found in abundance in the planet.
• Examples: 55 Cancri Ab, HD 209458 b (both speculated)
• Notes: Can currently spawn within a star's lava zone.

Class V Gas Giants

• Characteristics: The planet's temperature exceeds 1400 K. This classification is also given to cooler gas giants with lower than Jupiter.
• Examples: 51 Pegasi b, Upsilon Andromedae b (both speculated)
• Notes: Can currently spawn within a star's lava zone.

Ice Giants

• Characteristics: Surfaces are often composed of frozen materials heavier than gases, such as carbon or water.
• Examples: Uranus, Neptune
• Notes: Can currently spawn outside of a star's frost line.

Dwarf Planets

Ice Dwarfs

• Characteristics: Surfaces often similar to Ice Giants, with their surfaces containing frozen materials.
• Examples: Pluto, Sedna
• Notes: Will spawn outside of a star's frost line.

Rocky Dwarfs

• Characteristics: Surfaces are similar to Terrestrial Planets.
• Examples: Ceres
• Notes: Can spawn both inside and outside of the habitable zone.

Rogue Planets

• Characteristics: The planet is found independently from a star system.
• Examples: S Ori 70, Cha 110913−773444 (both speculated)

Development

Refinement of planetary spawning began during the 0.225 dev builds alongside Galaxy Generation process. These including implementation of calculations for the Roche limit, Hill Spheres, Orbital Periods and Velocity in a star system. Additional features were planning, including atmospheric pressure and chemicals, ocean chemicals and greenhouse effect calculations. Though some were partially implemented, development of these were paused and delayed until future versions.

Planetary Nebula and Rogue Planets are intended to be implemented into Tech Demo 4. The former was implemented in dev build 0.226.0.4 whilst the latter was added during 0.226.0.19. During dev build 0.226.0.16, work on explorable planetary surfaces began implementation into the game for future planetary landing mechanics.

Future dev builds are intended to feature further characteristics and astronomical objects generating within a planet's orbit such as moons and planetary rings, using the hill sphere implemented in 0.225's development cycle.