Planets: Difference between revisions
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The term planet refers to celestial bodies orbiting a [[star]] with a [[gravity]] in a specific range. The gravity of a planet has to be strong enough to hold fluids in a stable state (hydrostatic equilibrium) which prevents them from escaping the planet, and low enough to prevent nuclear processes to start as in stars. | The term planet refers to celestial bodies orbiting a [[star]] with a [[gravity]] in a specific range. The gravity of a planet has to be strong enough to hold fluids in a stable state (hydrostatic equilibrium) which prevents them from escaping the planet, and low enough to prevent nuclear processes to start as in stars. | ||
Some astronomical objects that meet the official criteria for planet status yet also happen to orbit a planet are instead classified as natural satellites or [[moons]]. When | Some astronomical objects that meet the official criteria for planet status yet also happen to orbit a planet are instead classified as natural satellites or [[moons]]. When the [[barycentre]] of the planet-moon system falls outside the planet, then both bodies would be considered planets and part of a double-planet system.<ref>https://www.universetoday.com/85749/is-the-moon-a-planet/</ref> | ||
==[[Terrestrial Planet]]s== | ==[[Terrestrial Planet]]s== | ||