retrograde motion
The "apparent" reverse or backwards motion of a planet as observed from Earth. The innermost planets appear to have a retrograde motion when viewed from Earth.
Venus.!
venus
Superior planets are in opposition when in the middle of their retrograde motion.
Retrograde motion.
neptune
All the models explain retrograde motion because it is such an obvious phenomenon. In Copernicus's model an outer planet goes into retrograde motion when the inner planet overtakes it so that it appears from the inner planet to be going backwards along the ecliptic.
Venus has no natural satellites and retrograde motion (orbits opposite direction it rotates).
"retrograde motion"
You observe its motion, with respect to the background stars.
Apparent retrograde motion.