Planet's synodic period - Time required for the planet to complete one complete orbit (Time that elapse between two successive identical configurations as seen from Earth). Planet's sidereal period - Time between two successive identical configurations (True orbital period of a planet, the time it takes the planet to complete one full orbit of the Sun). For inferior planets: Orbit smaller than Earth's orbit (Example - Mercury, Venus) where: For superior planets: Orbit larger than Earth's orbit (Examples - Mars, Jupiter, Saturn) where: |