What's a Planet?

- planet (from Greek "wandering star")

Planet
Classes

Name Object - System Atmosphere Surface Core Surface H2O Orbits around Gravitationally Dominant Hydrostatic Equilibrium IAU definition
Class A
Theoretical - go find it! variable variable variable variable star (s) - decaying no - dissipation disk no - dissipation disk undefined
Class B Lagrange 3, 4, 5 Theoretical - go find it! variable variable variable variable star (s) no - multiple planets yes undefined
Class C Asteroid 4 Vesta - Sol none solid - metallic solid - metallic none star (s) yes no - irregular Small 'Solar System' Body
Class D
Theoretical - go find it! none solid - metallic solid - metallic none star (s) yes yes Planet
Class E
Gliese 581e - Gliese 581 none solid - metallic molten none star (s) yes yes Planet
Class F Mercurian Mercury - Sol < 500ppb solid - metallic molten none star (s) yes yes Planet
Class G Prototerrestrial Theoretical - go find it! < 1 % molten molten none star (s) no - accretion disk yes Protoplanet
Class H
Mu Arae c - Mu Arae 1ppm - 1% molten molten none star (s) yes yes Planet
Class I
Theoretical - go find it! 500ppb - 1ppm motlen molten none star (s) yes yes Planet
Class J
Corot 7b - Corot 7 < 500ppb motlen molten none star (s) yes yes Planet
Class K Venusian Venus - Sol 1ppm - 1% solid - metallic molten none star (s) yes yes Planet
Class L
Theoretical - go find it! 500ppb - 1ppm solid - metallic molten none star (s) yes yes Planet
Class M Terrestrial Earth - Sol 500ppb - 1ppm solid - metallic molten liquid star (s) yes yes Planet
Class N
Theoretical - go find it! 500ppb - 1ppm solid - metallic molten ice star (s) yes yes Planet
Class O Martian Mars - Sol < 500ppb solid - metallic molten ice star (s) yes yes Planet
Class P Planetoid Ceres - Sol variable variable variable variable star (s) no - asteroid belt yes Dwarf Planet
Class Q Binary Pluto - Sol variable variable variable variable barycenter no - binary planet yes Dwarf Planet
Class R Satellite Luna - Sol variable variable variable variable planet (s) no - satellite variable Satellite
Class S Proto Gas LRLL 31 > 1% - H, He variable gas, molten variable gas, molten none star (s) no - accretion disk no - accretion disk Accretion Disk
Class T
Theoretical - go find it! > 1% - H, He molten molten none star (s) yes yes Planet
Class U Jovian Jupiter, Saturn - Sol > 1% - H, He solid - metallic molten none star (s) yes yes Planet
Class V
Theoretical - go find it! > 1% - H, He solid - metallic solid - metallic none star (s) yes yes Planet
Class W
Uranus, Neptune - Sol > 1% - H, He solid - ice H2O, methane, ammonia ice star (s) yes yes Planet
Class X
GJ 1214b - GJ 1214 variable solid - ice liquid ice star (s) yes yes Planet
Class Y Comet 1P/Halley - Sol variable solid - ice H2O, methane, ammonia variable star (s) yes no - irregular Small 'Solar System' Body
Class Z Rogue Theoretical - go find it! variable variable variable variable none n/a variable undefined