orbital eccentricity

This page refers to eccentricity in astrodynamics. For other uses, see the disambiguation page eccentricity. In astrodynamics, under standard assumptions, any orbit must be of conic section shape. The eccentricity of this conic section, the orbit's eccentricity, is an important parameter of the orbit that defines its absolute shape. Eccentricity may be interpreted as a measure of how much this shape deviates from a circle.
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