An apparent eastward motion of a planet from night to night compared to the background stars (as viewed from Earth) is referred to as
A) rising (if in the east) or setting (if in the west).
B) direct motion.
C) precession.
D) retrograde motion.

Question

Quizplus · Accepted Answer

Direct motion (or prograde motion) refers to the normal eastward movement of a planet across the sky relative to the stars, as observed from Earth. This is the typical direction in which planets appear to move, opposite to the occasional westward, or retrograde, motion.

An Apparent Eastward Motion of a Planet from Night to Night