Glossary : Eccentricity
(aka ecce or EO or e) One of the six Keplerian elements
describes the shape of an orbit. In the Keplerian orbit model, the
satellite orbit is an ellipse, with eccentricity defining the "shape" of
the ellipse. When e=0, the ellipse is a circle. When e is very near 1,
the ellipse is very long and skinny.
Courtesy of NASA
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