A planet is a celestial body typically found in orbit around a star. Planets are typically spheroid and may have other bodies in orbit of themselves such as moons, rings or artificial satellites which can include communications or defense technology or orbital facilities such as starbases and shipyards. There are two basic types of planets, small solid rocky planets which may have a thin atmosphere and gas giants which are almost entirely atmosphere. Small planet-like bodies are planetoids or dwarf planets and smaller bodies still are asteroids.
Planetary Classification[]
The Federation classified planets it cataloged based on criteria such as atmospheric composition, surface temperature, and conditions, the size of the body, and the presence of animal and plant life. This system is used to determine the suitability of the planet for exploration, colonization, and scientific research.
Each class of planet is assigned a letter in the alphabet based on its suitability. For example, Class M (sharing meaning with the Vulcan designation Minshara class) is applied to planets that can support life without any special circumstances, such as Earth, Vulcan, or Cardassia. (ST reference: Star Charts; ENT episode: "Strange New World")
The Klingons had a separate classification system, one of which is a Q'tahL class. (ENT episode: "Sleeping Dogs")
- Two partially conflicting listings of planetary classification have been given by the 1989 book The Worlds of the Federation and the 2002 book Star Charts. The two sources have classes D, K and M in common, but otherwise assign classifications to conflicting letters.
Star Charts classifications[]
Class | Description | Surface | Atmosphere |
---|---|---|---|
Class A | geothermal | partially molten | hydrogen compounds |
Class B | geomorteus | partially molten, high temperature | extremely tenuous, chemically inactive |
Class C | geoinactive | low temperature | partially frozen |
Class D | asteroid/moon | barren and cratered metallic, iron-nickel-silicate | none or very tenuous |
Class E | geoplastic | molten, high temperature | hydrogen compounds and reactive gases |
Class F | geometallic | volcanic | hydrogen compounds |
Class G | geocrystalline | crystallizing | carbon dioxide, some toxic gases |
Class H | desert | hot and arid, little or no water | may contain heavy gases and metal vapors |
Class I | gas supergiant | tenuous, comprised of gaseous hydrogen and hydrogen compounds, radiates heat | variable pressure and composition, may contain water vapor |
Class J | gas giant | tenuous, comprised of gaseous hydrogen and hydrogen compounds, radiates some heat | variable pressure and composition |
Class K | adaptable | barren, little or no water | thin, mostly carbon dioxide |
Class L | marginal | rocky and barren, little water | oxygen/argon, high concentration of carbon dioxide |
class M | terrestrial | water abundant | nitrogen, oxygen and trace elements |
Class N | reducing | high temperature | extremely dense, carbon dioxide and sulfides |
class O | pelagic | 80%+ water | nitrogen, oxygen, and trace elements |
class P | glaciated | 80%+ water ice | nitrogen, oxygen, and trace elements |
class Q | variable | various | tenuous to dense |
class R | rogue | maybe temperate due to geothermal venting | primarily volcanic outgassing |
class S | ultragiant | tenuous, comprised of gaseous hydrogen and hydrogen compounds, radiates considerable heat | variable pressure and composition, may contain water vapor |
class T | ultragiant | tenuous, comprised of gaseous hydrogen and hydrogen compounds, radiates considerable heat | variable pressure and composition, may contain water vapor |
class Y | demon | 500°K+ | turbulent, saturated with toxic chemicals and therionic radiation |
Worlds of the Federation classifications[]
Class | Description | Surface | Atmosphere |
---|---|---|---|
Class A | gas giant which radiates heat; a failed star | tenuous if present | reducing, including methane |
Class B | gas giant which does not radiate heat | tenuous if present | reducing |
Class C | high surface temperature | iron/silicate | dense reducing |
Class D | asteroid | nickel-iron/silicate | tenuous if present |
Class E | large molten core | silicate, with some metals | reducing/oxidizing |
Class F | less than a billion years old | silicate, with some metals | oxidizing |
Class G | desert | silicate | thin oxidizing |
Class H | geologically active | silicate | variable |
Class I | small and young | metallic/silicate | very dense fluid |
Class J | moon | silicate | tenuous, including noble gases |
Class K | adaptable with pressure domes | silicate | tenuous with some water |
Class L | geologically inactive | silicate/water | oxidizing |
Class M | geologically active | silicate/water | oxidizing |
Class N | pelagic | entirely water | oxidizing |