Retrograde motion
A) is observable for planets located between Earth and the sun.
B) is observable for planets more distant from the Sun than is Earth.
C) is only observable for the moon.
D) is observable for all planets.
E) none of the above

Question

Quizplus · Accepted Answer

Retrograde motion is the apparent backward motion of a planet as seen from Earth. It occurs when Earth overtakes and passes another planet in their respective orbits around the Sun. Therefore, retrograde motion is observable for planets more distant from the Sun than is Earth. Retrograde motion is the apparent backward motion of a planet in its orbit as observed from Earth. This occurs when Earth catches up to and passes the slower-moving outer planet, making it appear to move in the opposite direction briefly. Therefore, retrograde motion is observable for planets more distant from the Sun than is Earth.

Retrograde Motion