The term "retrograde motion" means that a satellite (moon) moves in the opposite direction from what would be expected or common.
A retrograde orbit is one opposite the rotation of the planet being orbited. This is the case with satellites of Jupiter and Saturn that are likely captured asteroids.
The planet Venus exhibits retrograde rotation because it spins very slowly in a clockwise direction (as seen from above). The dwarf planet Pluto likewise rotates clockwise. All other planets display counter-clockwise rotations, and all planets orbit the Sun counter-clockwise. (The planet Uranus is tilted on its side, and could be considered retrograde as well.)
The planets don't have to "do anything" to "go into" retrograde motion. The retrograde motion, the "moving backward" that planets do as we watch them cross the night sky over the weeks, is due to the nature of the orbit of a planet and to our view of that orbit from earth.
The motion of the planets are elliptical motions
A retrograde motion.
If Earth didn't revolve around the sun, there would be only one season, instead of all four. Also, the retrogrades (apparent backward motion of planets would be more dramatic because planets would pass the earth faster. One other difference would be that you wouldn't be able to tell your longitude by the sun.
In the Geocentric Hypothesis (Earth-centered), retrograde motion can only be explained by describing the motion of planets as complex, curlicue paths. In the Heliocentric Hypothesis (Sun-centered), retrograde motion is described as changes in relative motion as the Earth overtakes a slower-moving planet in an outer orbit, or is overtaken by a faster-moving planet in an inner orbit. In the Heliocentric Hypothesis, all planets move in more-or-less circular orbits at more-or-less constant speeds, but planets closer to the Sun move faster. Thus, the Earth can overtake and pass each of the outer planets, making them appear to move "backward" (retrograde) for a time.
retrogade motion
The planets don't have to "do anything" to "go into" retrograde motion. The retrograde motion, the "moving backward" that planets do as we watch them cross the night sky over the weeks, is due to the nature of the orbit of a planet and to our view of that orbit from earth.
Pendulum?
retrogade motion
Apparent motion of the planets.
These are called Surface waves
That is called 'apparent retrograde motion'.See the related link listed belowfor more information.
The motion of the planets are elliptical motions
Pronation is the motion that turns the palm of the hand downward or backward.
Astronomy.
Celestial Mechanics. Or Astronomy
The backwards force affects a motion by slowing it down