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Can you explain Mercury's retrograde motion? Do other planets appear to do this also?

Robert Schneider, Merida, Mexico
RELATED TOPICS: PLANET | MERCURY
Mercury
When astronomers talk about retrograde motion, generally they refer to the apparent motion outer planets make as Earth passes them while orbiting the Sun. Most of the time, all the outer planets appear to move eastward through our sky. During retrograde motion, however, each appears to reverse direction and head westward. Note that this is an apparent motion. The same thing happens when you, in a car, pass another car going in the same direction. While you are passing that car (and because you are traveling faster), it appears to move in the opposite direction.

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