<P> Retrograde motion, or retrogression, within the Earth's atmosphere is seen in weather systems that move from east to west through the Westerlies or from west to east through the trade wind easterlies . </P> <P> Artificial satellites are usually launched in the prograde direction, since this minimizes the amount of fuel required to reach orbit by taking advantage of the Earth's rotation (an equatorial launch site is optimal for this effect). </P> <P> If formed in the gravity - field of a planet as the planet is forming, a moon will orbit the planet in the same direction as the planet is rotating and is a regular moon . If an object is formed elsewhere and later captured into orbit by a planet's gravity, it can be captured into a retrograde or prograde orbit depending on whether it first approaches the side of the planet that is rotating towards or away from it . This is an irregular moon . </P> <P> In the Solar System, many of the asteroid - sized moons have retrograde orbits, whereas all the large moons except Triton (the largest of Neptune's moons) have prograde orbits . The particles in Saturn's Phoebe ring are thought to have a retrograde orbit because they originate from the irregular moon Phoebe . </P>

The minor planets revolving between the orbit of jupiter and mars are called