orbital resonance

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orbital resonance

An effect in celestial mechanics that arises when two orbiting bodies have periods of revolution that are in a simple integer ratio allowing each body to have a regularly recurring gravitational influence on the other. Orbital resonance may stabilize the orbits and protect them from perturbation, as in the case of the Trojan group of asteroids, which are held in place by a 1:1 resonance with Jupiter. On the other hand, orbital resonance may destabilize one of the orbits, ejecting the body concerned, changing the eccentricity of its path, or sending it into a different orbit. This second effect of orbital resonance accounts for why there are virtually no asteroids in certain regions of the main asteroid belt (see Kirkwood gaps). Laplace resonance is a form of orbital resonance that occurs when three or more orbiting objects have a simple integer ratio between their orbital periods. For example, the Jovian satellites Io, Europa, and Ganymede have periods of revolution in the ratio 4:2:1.
References in periodicals archive ?
Astronomers honored Laplace by naming any orbital resonance among three or more bodies a Laplace resonance. Io, Europa, and Ganymede form the only known example in our solar system.
Instead, Lainey and his colleagues, using 116 years of positional observations of Jupiter's moons, determined that the Laplace resonance is slowly breaking.
It came as a surprise to many that the Galilean moons are slowing leaving their Laplace resonance. Lainey and his colleagues make no prediction as to when the resonance will be broken.
For every orbit that Ganymede makes, Europa makes two and Io four - a type of gravitational relationship called a Laplace resonance.