Kozai

In celestial mechanics, the Kozai mechanism, or the Lidov–Kozai mechanism, is a perturbation of the orbit of a satellite by the gravity of another body orbiting farther out, causing libration (oscillation about a constant value) of the orbit's argument of pericenter. As the orbit librates, there is a periodic exchange between its inclination and its eccentricity.

The effect was described in 1961 by the Soviet specialist in space dynamics Michael Lidov (Russian: ) while analyzing the orbits of artificial and natural satellites of planets, This result was reported by Lidov at the Conference on General and Practical Topics of Theoretical Astronomy, held in Moscow on 20 - 25 November 1961. Among the participants of that conference was a Japanese astronomer Yoshihide Kozai (Japanese: ) who soon published this same result, in application to the orbits of the asteroids. Since then, this effect has been found to be an important factor shaping the orbits of irregular satellites of the planets (the moons in the Kozai resonance being Jupiter's Carpo and Euporie, Saturn's Kiviuq and Ijiraq, Uranus's Margaret, and Neptune's Sao and Neso; the effect also explains the non-uniform distribution of irregular satellite inclinations), trans-Neptunian objects, and a few extrasolar planets and multiple star systems.

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