Problem
The planets of the solar system all orbit the Sun in the same sense: counterclockwise as seen ?'om above the Earth's north pole. Imagine a '?vrong-way" planet orbiting the Sun in the opposite (clockwise) sense, on an orbit of semimajor axis length a=l.5 AU. What would the sidereal period of this planet be? What would its synodic period he as seen from the Earth? What would its synodic period be as seen from Mars?