Time required for a body in the solar system to return to the same or about the same position relative to the Sun as seen from Earth.
The Moon's synodic period is the time between successive recurrences of the same phase (e.g., the period between one full moon and the next). A planet's synodic period is the time required for Earth to overtake it as both go around the Sun or (in the case of fast-moving Mercury or Venus) for the other planet to overtake Earth. See also sidereal period .