Astronomy: Retrograde Motion

Astronomy: Retrograde Motion
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Concepts & Techniques
Retrograde Motion Apparent retrograde motion is the apparent motion of a planet 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.

Commentary

Commentary

Source: Wikipedia (CC BY-SA)
Retrograde Motion Apparent retrograde motion is the apparent motion of a plan et 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.

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Source: Internal
Why Retrograde Motion matters: These foundational ideas and techniques are the tools astronomers use to measure, classify, and understand everything from nearby planets to the most distant galaxies. The earliest recorded use of prograde was in the early 18th century, although the term is now less common.

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Source: Internal
Deep dive: Retrograde Motion Retrograd e Motion continues to be an active area of research in modern astronomy. Source: https://en.wikipedia.org/wiki/Apparent_retrograde_motion (Wikipedia, CC BY-SA)