Planetary Classification: Difference between revisions
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* ''Star Charts classifications flawed w.r.t. giant planets'' | * ''Star Charts classifications flawed w.r.t. giant planets'' | ||
** ''Radii are physically impossible'' | ** ''Radii are physically impossible'' | ||
** ''No | *** ''Jupiter diameter ~140,000km, maximum theoretical possible planetary diameter ~400,000km, but class T planets go up to 120m km?'' | ||
* '' | *** ''Adding more mass generally tends to increase'' density'', not radius; proximity to sun increases size but only so far'' | ||
** ''No acknowledgement of ice giants (not widespread distinction yet at time of writing) despite physically distinct characteristics'' | |||
*** ''All Star charts giant classes are predominantly hydrogen-based, ice giants (i.e. Neptune, Uranus) are water/ammonia-based with very slim hydrogen envelopes'' | |||
** ''All gas giants listed as being in "cold zone" beyond ecosphere, which doesn't fit later discoveries'' | |||
*** ''Written before discovery of numerous hot Jupiters by various exoplanet surveys'' | |||
* ''Alteration:'' | |||
** ''Class I ice giant'' | |||
** ''Class J cold gas giant'' | |||
*** ''Type I through V using [https://en.wikipedia.org/wiki/Sudarsky%27s_gas_giant_classification Sudarsky's schema]'' | |||
** ''Class S gas dwarf'' | |||
*** ''[http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1989A&A...215..177S&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES Theoretical protoplanet state] leading to ice giants, potentially also gas giant that has lost atmosphere to solar wind ablation'' | |||
** ''Class T hot gas giant (fka hot Jupiter)'' | |||
*** ''Type I through V using Sudarsky's schema'' | |||
(''Star Charts'' unless otherwise referenced) | (''Star Charts'' unless otherwise referenced) | ||
[[Category:Astronomy]] | [[Category:Astronomy]] | ||
Revision as of 11:51, 10 January 2018
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
- Jupiter diameter ~140,000km, maximum theoretical possible planetary diameter ~400,000km, but class T planets go up to 120m km?
- Adding more mass generally tends to increase density, not radius; proximity to sun increases size but only so far
- No acknowledgement of ice giants (not widespread distinction yet at time of writing) despite physically distinct characteristics
- All Star charts giant classes are predominantly hydrogen-based, ice giants (i.e. Neptune, Uranus) are water/ammonia-based with very slim hydrogen envelopes
- All gas giants listed as being in "cold zone" beyond ecosphere, which doesn't fit later discoveries
- Written before discovery of numerous hot Jupiters by various exoplanet surveys
- Radii are physically impossible
- Alteration:
- Class I ice giant
- Class J cold gas giant
- Type I through V using Sudarsky's schema
- Class S gas dwarf
- Theoretical protoplanet state leading to ice giants, potentially also gas giant that has lost atmosphere to solar wind ablation
- Class T hot gas giant (fka hot Jupiter)
- Type I through V using Sudarsky's schema
(Star Charts unless otherwise referenced)