Planetary Classification
Facts
- Planetary classification system established by mid-23rd century
- Descends from similar classification systems established by Vulcan Science Directorate, UESPA (ENT, TOS)
Classifications
Class A
Class B
Class C
Class D
- Terrestrial
- Airless body, often an asteroid or moon
Class E
Class F
Class G
Class H
- Terrestrial
- Arid world
- Atmosphere often saturated with heavy gasses or metallic vapors
- Little to no surface water
- Generally uninhabitable to humanoid life
Class I
Class J
- Gas giant
Class K
- Terrestrial
- Adaptable world
- Generally thin atmopshere
- Little to no surface water
- Surface conditions suitable for life with aid of pressure domes or life support technology (TOS: "I, Mudd")
- Often pre-terraforming state
Class L
- Terrestrial
- Barely habitable or habitable with minimal technological aid
- Often pre-terraforming state
Class M
- Terrestrial
- Previously known as Minshara-class by Vulcan Science Directorate, Earth-type by UESPA (ENT, TOS)
- Significant surface water, below 80% coverage
- Atmosphere consisting of nitrogen, oxygen, trace elements
- Habitable by humanoid life
- Subdivided into type 1-4, indicating most to least suitable for humanoid life (TNG: "The Bonding")
Class N
- Terrestrial
- Thick atmosphere, often saturated with sulfur compounds
- High surface temperature due to atmospheric greenhouse effect
- Generally uninhabitable for humanoid life
Class O
Class P
Class Q
Class R
Class S
Class T
Class Y
- Terrestrial
- Colloquially known as "demon"-class (VOY: "Demon")
- Extremely high surface temperatures
- Corrosive and/or toxic atmosphere
- Thermionic discharges from surface-level metallic hydrogen deposits common (VOY: "Demon")
- Planetary conditions can lead to vessel hazards even at standard orbital altitude (VOY: "Demon")
Notes
- Star Charts classifications flawed w.r.t. giant planets
- Radii are physically impossible
- No distinction between gas giants and ice giants despite physically distinct characteristics
- Possibly replace gas giant classification schema with something like Sudarsky schema + ice giant? Compare to canon class J & class T
(Star Charts unless otherwise referenced)