The term "retrograde" means "backward". Obviously, no planet actually goes backwards. However, from our perspective here on Earth, all of the planetary bodies (except for the Sun and Moon) appear to move backwards. Imagine that you're driving down the road parallel to a set of railroad tracks. A train is speeding along to your left, and you pass the train. It appears to be going backwards, but what is really happening is that you are going faster.

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