Kerbal Star Systems Wiki

The Astronomical Body Classification System (ABCS) of bodies is a method Kerbal Scientists use to classify new planets according to properties they already know.

Classification Method

(Planet Class)(Temperature Grade)-(Parent Star)(If the star orbits another star)-(Planet(Moon if the body is a moon(Submoon if the body orbits a moon)))

List of Planet Classes:

  • A - Asteroid, not large enough to maintain spherical shape (Minmus, Jeln)
  • D - Desert (Duna, Alva)
  • E - Terra, has water and land on the surface (Kerbin, Blalo)
  • F - Icy world, surface covered entirely in ice sheets (Elno, Kel)
  • G - Gentle Giant, a gaseous planet with the ability to host life (Laevo)
  • I - Icy selena, a planet with large amounts of ice and rock on the surface
  • J - Gas planet, mostly made up of Hydrogen and Helium (Jool, Voon)
  • M - Gas Dwarf, very small gaseous bodies nearly too small to be gaseous (Iain, Telim)
  • N - Ice Giant, smaller gas giants that have an abundance of heavier chemicals (Oran, Naal)
  • O - Ocean World, world covered entirely with a very deep ocean (Aquel, Nelvem)
  • R - Lone planet, no host star
  • S - Selena, no atmosphere & silicate surface (Mun or Moho)
  • W - Wet Desert, a planet with a runaway greenhouse effect, (Eve, Sern)
  • X - Exotic class, oceans comprised of material not water (Laho, Sulph, Hetoo)

List of Temperature Grades:

  • F - Frozen, temperature range: below 173 K (-100°C)
  • P - Cool/cold, temperature range:173 K (-100°C) - 273 K (0°C)
  • M - Temperate (Kerbin-like), temperature range: 273 K (0°C) - 303 K (30°C)
  • T - Warm, temperature range: 303 K (30°C) - 373 K (100°C)
  • H - Hot, temperature range: greater than 373 K (100°C)

Habitability Index:

The following terminology refers to the abundance and biodiversity of life currently supported by a celestial body. Classification is (subcategory) (category). For example: Duna is a Obscure Organic world.

  • Sterile: An astronomical body that is completely inhospitable to life, and contains little to no organic matter in its composition, or may have some factors suitable for life, but others that prohibit the formation of life (Moho, Eve, Mun, Jool)
  • Organic: An astronomical body that contains suitable conditions for life, but living things are either absent or unconfirmed. Life may have been present in the past, and could possibly arise in the future.
    • Hostile - The planet contains organic materials but is incapable of supporting life (Nisc, Clorum)
    • Extinct - Life may have once existed but it has since disappeared (Alva, Alar)
    • Prevital - Life is likely to evolve but possibly hasn't due to young age (Mer)
    • Obscure - The Chances of life are quite possible but hasn't been confirmed (Duna, Laythe)
  • Sub-Habitable: An astronomical body with biodiversity and abundance of life that is inferior to what is seen on Kerbin. This usually includes young planets and worlds that have experienced recent extinction events.
    • Primordial - Only microscopic life
    • Complex - Macroscopic life is present (Blalo, Narath)
  • Habitable: An astronomical body that is similar, in terms of biodiversity and biomass, to the planet Kerbin. (Kerbin, Ora, Hetoo)
  • Super-Habitable: Any astronomical body that hosts a biosphere with greater biodiversity and biomass than Kerbin is considered superhabitable. Superhabitability is usually a result of age, size, highly suitable conditions or any combination of these factors. (Taythe, Laevo)

List of Star IDs:

If the planet orbits a star that orbits another star, the designation adds a letter on (Example: Nessus III -> 9C)

Kerbol - 0

Kernim - 1

Kelin - 2

Kirb - 3

Kormin - 4

Kerolon - 5

Kerilim - 5B

Kelaris - 6

Kirlim - 6B

Kerbos - 6C

Korlon - 7

Kelnis - 8

Nessus - 9

In Case of Confusion

  • A-Class bodies can be moons, comets, or asteroids
    • All A-Class worlds cannot attain hydrostatic equilibrium.
  • D-Class bodies have very dry surfaces and atmospheres due to surface climate conditions.
    • Water on the surface can be in solid form, so long as it isn't in large quantities.
    • Do not possess large quantities of any liquid.
  • E-Class worlds have both water and land on the surface
    • It can either be a small lake or a tiny island
    • They do not require life to be classified in E-class
  • F-Class worlds are entirely covered in ice
    • An atmosphere is not required
  • M-Class worlds have a radius below 2000 kilometers.
  • O-Class worlds are completely covered in water
    • Subsurface oceans don't count as O-Class
  • X-Class worlds have seas of chemicals not made of water
    • This includes molten lava oceans.
  • W-Class worlds have no liquids on the surface, but instead humid atmospheres
  • Life worlds are planets that either have life, or have once had life.
  • Planets are identified with a number, moons with a letter, and submoons with a number
  • Habitability is purely a measure of the current state of living things on a celestial body. It is variable over time and is not necessarily a reflection of the conditions of a planet. For example, Blalo is considered Sub-Habitable because of a past extinction event that wiped out a large portion of Blalo's original biomass, yet the planet has a very suitable climate for kerbal habitation.
  • Rogue planets are not classified by their star, but instead in order of distance from Kerbin (the closest rogue planet is R-1, next is R-2, etc.)
  • Due to the high amounts of variation in R-Class bodies, it is decided that the R in R class will be added onto the designation (for example, an E-Class rogue's would be REM-1). They would still be referred to as R-Class, however.