Dear Frank, Gianni, Robert, Bill and all, It seems that there is much interest in directly solving the multibody Kepler's law for at least those objects in our solar system. This is working from near basic principles rather than developing perturbations to curve fitting polynomial circular functions. The method allows for extremely good extrapolation rather than just the extremely good interpolation of of the trigonometric series approach. Trigonometric series may be the most efficient approximation methods, but cover only a very restricted range of the variables outside of which they fall apart rapidly.
The method may seem, and in fact may be overkill, for the data extraction required to design and build a sundial but, a sundial is a fitting monument to the achievement of the method! Edley.
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