Gravity Simulator: "The Kozai Mechanism
The Kozai Mechanism causes a periodic exchange between the inclination and eccentricity of an orbit.
It has been theorized that the Kozai Mechanism is responsible for the high eccentricities observed in the orbits of exosolar planets. If the parent star has a massive yet unseen substellar companion, orbiting at a great distance, and in an orbit highly inclined to the plane of the planets' orbits, the Kozai Mechanism should induce high eccentricities into the orbits of the planets.
It is also theorized that the Kozai Mechanism may be responsible for the high eccentricities observed in the orbits of many Kuiper Belt Objects such as 2003 UB313. The pull of the Milky Way Galaxy causes an object with a high eccentricity to periodically trade this eccentricity for a gain in inclination."
