It is physically impossible for a free macro body to revolve around another moving body in any type of geometrically closed path. This can be observed by watching a person trying to move around another person running along a defined path. Planets are free macro bodies, the central body (sun) is a moving body and the circular/elliptical path is a geometrically closed path.

This being the case, why does every textbook and other works of literature show the planetary orbits and paths of other orbiting bodies as circular/elliptical?

See: http://vixra.org/pdf/1311.0018v1.pdf