Wednesday, July 11, 2012

The Meaning of Retrograde Motion



[Retrograde motion is an optical illusion, created by differences in orbital speed.  Both planets continue to circle the Sun but from the perspective of Earth, the other slows, stops, and changes direction.]

THE MEANING OF RETROGRADE MOTION

“Watch the stars, and from them learn. To the Master's honor all must turn, each in its track, without a sound, forever tracing Newton's ground.”
~Albert Einstein~

What does retrograde mean?

Retrograde comes from the Latin retrogradus, “to move or step backwards”. A retrograde planet appears to be moving normally, then slows down to a stop, moves in reverse, then slows to a stop again, to correct its direction. These changes are actually an optical illusion created by differences in the relative orbital speeds of Earth and the other planet involved.

Since the effect is produced by our perspective, the Sun and Moon never appear retrograde. The North and South Lunar nodes always move backwards, compared to the planets. Although they seem random, the retrograde and direct motion of each planet is part of a regular pattern.

How is retrograde motion experienced energetically?

1. STRONG: When retrograde, a planet is at its nearest point to the Earth and appears very bright in the sky, if visible. Things ruled by the planet become prominent, both their issues and the means to address them.

2. ILLUSIONARY: Since retrograde motion is an optical illusion, things ruled by the planet are easily misperceived now or our own misperception of them becomes apparent.

3. REPEATED: The planet passes through the same part of the sky three times: once before it stops, backwards when retrograde, then forward again after correcting its motion. Things ruled by the planet are repeated, delayed, or feel inevitable. Since the planet is retracing the same ground, the past can return to be addressed, while new projects move in unexpected ways, or lose steam until after the planet corrects its motion.

4. SLOW: A retrograde planet makes several changes in both direction and speed. Coming both in and out of retrograde, it slows to a stop to change direction. While moving backwards the planet remains slow moving, compared to its direct motion. Planets at their extremes (fast, slow, and stopped) are potent. A slow or stationing planet stays near the same degree, making its aspects last longer.

5. REORIENT: Exactly halfway through its retrograde motion, most planet makes an opposition to the Sun. They move like the Full Moon. They rise at dusk, are visible during the night, and set at dawn. Since they are closer to the Sun than Earth, Mercury and Venus form an inferior conjunction instead. They begin as an evening star, disappear in the glare of the Sun, and reappear as a morning star. The Sun represents our conscious mind and the night, the unconscious. Just as the planet moves from night to day, we must reintegrate things into our conscious mind.

THE LENGTH OF PLANETARY STATIONS

How long does the planet actually stay motionless?

If we look around the exact time Mercury turns retrograde, we see the planet is only stationary a short time. Otherwise it moves so slowly, in seconds, that it only appears motionless.  For example, look at the movement of Mercury around its July 15th, 2012 retrograde station:

3:16 PM EST = 1' minute
6:16 PM EST = 12” seconds
7:16 PM EST = 0º 0' 0” NO MOVEMENT = RETROGRADE STATION
8:16 PM EST = -12” seconds
11:16 PM EST = -1' minute

º = degree, each zodiac sign has 30 degrees
' = minute, each degree has 60 minutes
“ = second, each minute has 60 seconds

The apparent width of Mercury, more formally called its angular diameter, varies in historical sources, from 3' to 1' minutes. Contemporary astronomers use a much smaller number, a range of 4.5”to 13” seconds. (Celestial objects appear larger to the naked eye than in a telescope, so figures in older sources tend to be bigger.) This size suggests a planet would have to move at least a few minutes before the change was noticeable.

How long is a station?

Different sources have conflicting numbers for the length of Mercury's station, from one to seven days.  The answer depends on your definition. For example, look at the movement of Mercury around its July 15th, 2012 retrograde station:

7/11/12 11º 53' Leo = Different degree = 17 minutes movement
7/12/12 12º 10' Leo = Same degree = 12 minutes movement
7/13/12 12º 22' Leo = Same degree = 8 minutes movement
7/14/12 12º 30' Leo = Very little movement = 3 minutes movement
7/15/12 12º 33' Leo = RETROGRADE STATION = 0 degrees movement
7/16/12 12º 31' Leo = Very little movement = -2 minutes movement
7/17/12 12º 24' Leo = Same degree = -7 minutes movement
7/18/12 12º 12' Leo= Same degree = -12 minutes movement
7/19/12 11º 56' Leo = Different degree = -18 minutes movement

º = degree, each zodiac sign has 30 degrees
' = minute, each degree has 60 minutes
“ = second, each minute has 60 seconds

On the day Mercury turns retrograde, it appears motionless. On the day before and after, it only moves a few minutes. Two days before and after, it moves several minutes but is still at the same degree.

A station is a planet resting at the location where it changes direction. (Technically, it is only motionless for a brief period.  Otherwise it moves incredibly slowly near this time, in seconds.) By this definition, Mercury stations one day. If very near that point is included, then Mercury stations for three days. A difference of only a few minutes would not be visible to the naked eye. Generally the degree where a planet stations becomes very sensitive, Mercury stays at the same degree for seven days. This explains the wide range of days listed for planetary stations.


[After Mercury stops to turn backwards, it is still slow moving compared to its direct motion.  Slow moving planets are potent since the aspects they make are longer lasting.]

Why is speed important? Retrograde is about backwards motion.

A retrograde planet makes several changes in both direction and speed. Coming both in and out of retrograde, it slows to a stop to change direction. While moving backwards the planet remains slow moving, compared to its direct motion. Retrograde Mercury's fastest motion is between the two stations, at its inferior conjunction to the Sun. During the July 2012 retrograde, its fastest motion is -44' minutes. In comparison, at the middle of its next direct movement, its superior conjunction to the Sun, it moves +1º 54'. Almost twice as fast. Its average daily speed is 59' 8”, just under 1º.

The number of days, degrees, and speed varies slightly each retrograde for each planet. The slower the motion, the stronger the retrograde. Their backwards speed at the inferior conjunction (Mercury and Venus) or opposition (Mars, Jupiter, Saturn, Uranus, Neptune, Pluto) to the Sun, is an indicator of relative strength.

Planets at the extremes of their motion (fast, slow, and stopped) are potent. A slow or stationing planet stays near the same degree, making its aspects last longer.  Although we focus on the motionless station, very slow planets are also powerful. This explains why we feel the influence of a retrograde planet before and after the dates listed for it, they only represent its change in direction, not speed.

 © 2012, C. L. Matthews
[Image Source: Public domain, Wikipedia Commons]

2 comments:

  1. thanks Christopher, this is one of the better explanations I've come across. definitely thorough. the image is very useful as well.

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    1. You're welcome. I'm glad you found it helpful.

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