Editing Resonance (section)

===Orbital ===
{{Main|Orbital resonance}}

In [[celestial mechanics]], an [[orbital resonance]] occurs when two [[orbit]]ing bodies exert a regular, periodic gravitational influence on each other, usually due to their [[orbital period]]s being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of the bodies. In most cases, this results in an ''unstable'' interaction, in which the bodies exchange momentum and shift orbits until the resonance no longer exists. Under some circumstances, a resonant system can be stable and self-correcting, so that the bodies remain in resonance. Examples are the 1:2:4 resonance of [[Jupiter]]'s moons [[Ganymede (moon)|Ganymede]], [[Europa (moon)|Europa]], and [[Io (moon)|Io]], and the 2:3 resonance between [[Pluto]] and [[Neptune]]. Unstable resonances with [[Saturn]]'s inner moons give rise to gaps in the [[rings of Saturn]]. The special case of 1:1 resonance (between bodies with similar orbital radii) causes large Solar System bodies to [[Clearing the neighbourhood|clear the neighborhood]] around their orbits by ejecting nearly everything else around them; this effect is used in the current [[definition of planet|definition of a planet]].