Astrophysics (index)about

orbital element

(parameters describing an orbit)

Orbital elements are parameters that describe an orbit (the path of an astronomical object gravitationally bound to another, particularly, a repeating pattern) according to a reference plane and a direction through that plane.

The shape and size:

References for the orientation:

The elements describing the orbit's orientation use the line formed by the intersection of the orbit's plane with the reference plane (the "intersection" below):

(orbits,celestial mechanics)