What Planets Undergo Retrograde Motion. Retrograde motion in general, the planets move eastward relative to the fixed stars. During retrograde motion, however, each appears to reverse direction and head.
Retrograde motion was a great puzzle to ancient astronomers. The retrograde motion of the planets is an optical illusion, which is caused by planets orbiting the sun at different speeds to the earth.
What Planets Undergo Retrograde Motion Images References :