Apparent Retrograde Motion

Apparent retrograde motion is the motion of a planetary or other body in a direction opposite to that of other bodies within its system as observed from a particular vantage point. Direct motion or prograde motion is motion in the same direction as other bodies.

While the terms direct and prograde are equivalent in this context, the former is the traditional term in astronomy. Prograde was first seen in an abstract of an astronomy-related professional article in 1963.

Read more about Apparent Retrograde Motion:  Etymology, Retrograde Motion in Astrology

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