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mean motionThe constant angular speed that is required for a celestial body to complete one revolution of an (undisturbed) elliptical orbit of a specified semimajor axis.
Mean Motion(religion, spiritualism, and occult)
Because celestial bodies move in elliptical orbits, their speed varies depending upon their location. Mean motion refers to their average speed.
an element, or parameter, of the orbit of a celestial body that characterizes the dimensions of the orbit. The relation between the mean motion and the semimajor axis of the orbit is given by Kepler’s third law: the larger the semimajor axis, the more slowly the body, on the average, moves in its orbit. (SeeORBIT OF A CELESTIAL BODY.)