Halley's orbital period has varied between 74 and 80 years since 240 BC. Its orbit around the Sun is highly elliptical, with an orbitaleccentricity of 0
For an object in an eccentric orbitorbiting a much larger body, the length of the orbit decreases with orbitaleccentricity e, and is an ellipse. This can
eccentricities of the orbits of Uranus' inner satellites, and the anomalously high orbital inclination of Miranda. High past orbitaleccentricities associated
mean-motion orbital resonance with Enceladus, the effects of this resonance are too weak to explain Polydeuces's relatively high eccentricity.: 233 One