Using retrograde motion to understand and determine orbital parameters
The path of a planet on the celestial sphere when undergoing retrograde motion has a rich variety of forms that depend on the shape and orientation of its orbit and the timing of its opposition with the Earth. The observation of many retrograde paths can be used to determine the parameters of an external tilted elliptical orbit using only geometry and trigonometry. This approach fosters understanding of the geometrical significance of the orbital parameters and their role in determining the path Of the planet on the celestial sphere. © 2005 American Association of Physics Teachers.
American Journal of Physics
Thompson, Bruce G., "Using retrograde motion to understand and determine orbital parameters" (2005). Faculty Articles Indexed in Scopus. 1924.