Orbital eccentricity
parameter that determines the amount by which an orbit deviates from a perfect circle / From Wikipedia, the free encyclopedia
In astrodynamics, orbital eccentricity shows how much the shape of an object's orbit is different from a circle.
Eccentricity () is defined for all circular, elliptic, parabolic and hyperbolic orbits. It can take the following values:
- for circular orbits: is equal to zero,
- for elliptical orbits: is more than zero but less than 1,
- for parabolic trajectories: is equal to 1,
- for hyperbolic trajectories: is more than 1.