The Synodic Period of a Superior Planet as It Moves

Multiple Choice

The synodic period of a superior planet as it moves around the Sun as viewed from Earth is defined as the time between

A) conjunction and opposition on any orbit.
B) two successive passages through identical configurations, for example, two successive conjunctions.
C) two successive appearances of the planet at its highest point in the observer's sky.
D) two successive passages of Earth through the vernal equinox.