How many degrees does a planet move?

[MareSaturni]

Hi everyone!

I am back with more weird questions, lol!

I'd like to know if there's an established number for the amount of degrees a planets moves in a certain amount of time. I am sure there must be a math calculation for that, but I wouldn't know how to do it. I have no idea how many degrees a day (or a month) represents.

Now, I know that different planets move at different 'speeds'... the Moon probably covers a lot of degrees in one single month, whereas Pluto must take a long time to cover the 30 degrees that make one Sign.

There's also the retrograde problem... when a planet is retrograde, although we know that this is an optical illusion of some sorts, does it actually walk backwards in the chart? Since the chart is really a representation from what we see, if the planets appear to be retrograde in the sky, this should also appear in the chart. No? If yes, then this would affect the calculation...

And there's also the fact that some planets never stay for too long away from each other, like Mercury and the Sun, or Venus and the Sun... I'd like to know more about this.


Thank you very much for any help you can give me on this!

 

[cardlady22]

Don't forget the elliptical orbits that make certain points in the path "faster" than those that are farther out.

Is this calculation information similar to what you want to learn?
http://ceze.com/berglund/english/webcourse/lesson_17.htm

I found one of the more recent posts:
http://www.tarotforum.net/showpost.php?p=2938355&postcount=6

Every place I find a list/chart gives a variation.
http://www.gryphonastrology.com/planetaryspeed.html

Can't remember where I screenshot this one:

 

[MareSaturni]

Don't forget the elliptical orbits that make certain points in the path "faster" than those that are farther out.

I found one of the more recent posts:
http://www.tarotforum.net/showpost.php?p=2938355&postcount=6

The average daily motion of the planets are:

Moon 13 degrees 11 minutes - at it's fatest it peeks around 15 degrees

Mercury 59 minutes *
Venus 59 minutes *
Sun 59 minutes
Mars 31 minutes *
Jupiter 5 minutes *
Saturn 2 minutes *

The outers move at less than 1 minute per day

However the average disguises the real situation day by day as all the starred planets and the outers have periods of retrograde motion, as well as direct. That being said, Mercury, the fastest moviing of them reaches a speed of up to 1 degree 40 minutes.

Thank you for this link, Cardlady!
It's handy to have this information in minutes of arc, which is something observable in a chart. And also easier to convert into degrees!

So, when a planet goes retrograde, according to Minderwiz post, that means the planet 'loses' some of the degrees it went through, because it must go through them twice? Is that so?

Also, is it possible to know at which points the planet will move faster, due to its elliptical orbit? Is that visible in the chart?

Thank you!

 

[MareSaturni]

Can't remember where I screenshot this one:

Cardlady, this table you posted (the picture) is very handy! I like that it also has the amount of time each planets stays in eeach sign!

However, I am confused... it seems to show the movement of the planets in terms of hours/minutes/seconds, not degrees/arcmin/arcsec. Or am I wrong?

Do you convert when working with it?

 

[cardlady22]

I'm thinking there must be a terminology difference that I don't know. I was hopeless at keeping the types of averages straight in math class.

I was just showing examples of how you'll find a difference in lists. Better wait for the Big Boys to come answer.
I have a book by Kim Rogers-Gallagher called Astrology for the Light Side of the Future that features yet another set of notations on page 11. (She's a Sagittarius!)

*fondly pets my new iPod app that calculates for me*

 

[Minderwiz]

If we measure movement in degrees - and your question is specific about that - then the 'speed' with which a planet moves is governed primarily by its distance from the Sun. The further out it is, the more the circumference of the elipse and therefore the longer it will take for a planet to complete a circuit of the Zodiac.

The distances are given on this website

http://www.universetoday.com/15462/how-far-are-the-planets-from-the-sun/

This gives the distance in kilometres (and Astronomical Units) if we keep the maths over simple and treat the orbits as circular rather than elliptical, the distance that the planet travels in a circuit of the zodiac can be worked out by multiplying the kilometre distance (the radius of the circle) by 6.284 (2 x Pi). And in turn you could divide this circumference distance by 360 to get the distance of a degree in kilometres for each planet

If you want to go further you can adjust the distances for an elipse rather than a circle and also for a geocentric perspective by looking at the synodic period with Earth as the Earth also moves relative to the Sun

However for a beginner in Astrology simply learning the orbital times of the planets and the regrograde cycles is enough. As you develop there may well be other Astronomical aspects which are worth investigating.

 

[MareSaturni]

I'm thinking there must be a terminology difference that I don't know. I was hopeless at keeping the types of averages straight in math class.

I was the math class disaster, so don't feel bad!

*fondly pets my new iPod app that calculates for me*

*has no iPod*

The distances are given on this website

http://www.universetoday.com/15462/how-far-are-the-planets-from-the-sun/

This gives the distance in kilometres (and Astronomical Units) if we keep the maths over simple and treat the orbits as circular rather than elliptical, the distance that the planet travels in a circuit of the zodiac can be worked out by multiplying the kilometre distance (the radius of the circle) by 6.284 (2 x Pi). And in turn you could divide this circumference distance by 360 to get the distance of a degree in kilometres for each planet

If you want to go further you can adjust the distances for an elipse rather than a circle and also for a geocentric perspective by looking at the synodic period with Earth as the Earth also moves relative to the Sun

Thank you so much, Minderwiz. I think I have to take a look at my sister's math notebooks, because I have forgotten almost all about these calculations. But your instructions are very clear and I'll try them, at least to have some basic notions regarding the movement of the planets!

However for a beginner in Astrology simply learning the orbital times of the planets and the regrograde cycles is enough. As you develop there may well be other Astronomical aspects which are worth investigating.

Sorry for asking but... do planets go retrograde in a periodic manner? Like, after XX amount of time, they go retrograde? Do you know this information by heart, or do you rely on Astrological almanacs etc.?

Thank you!

 

[Rhinemaiden]

Hi Marina,

Go here...it's an ephemeris for 2012 with all the info you need... free PDF download... you'll see the planetary movement by degrees.

www.astro.com/swisseph/ae/2000/ae_2012.pdf

Good to see you!

 

[Minderwiz]

Sorry for asking but... do planets go retrograde in a periodic manner? Like, after XX amount of time, they go retrograde? Do you know this information by heart, or do you rely on Astrological almanacs etc.?

Thank you!

Retrograde motion is a product of the relative motions of planet, Sun and Earth. As seen from Earth For the outer planets, starting from the conjunction of planet and Sun the planet is in direct motion up to the point where the Sun trines the planet,after which the planet slows to it's station retrograde. (in the case of Mars, retrograde motion begins just before the trine). The planet remains retrograde till the second trine with the Sun, at which point having slowed down the planet turns direct again and remains direct through the conjunction with the Sun up to the first trine after the conjunction.

For Mercury and Venus the situation is a little different. These two inferior planets (that is between the Earth and the Sun) have two conjunctions with the Sun. One is when the planet is directly between the Earth and the Sun - this is called the inferior conjunction and at this conjunction the planet is retrograde.

The other is the superior conjunction, when the planet is on the other side of the Sun opposite Earth, at this point the planet is direct. Starting with the superior conjunction the planet remains direct till it reaches the point of Greatest Easter Elongation, the point at which its orbit starts to bring it back towards Earth. It appears to start decelerating just before this point and stations retrograde shortly after. It remains retrograde through the inferior conjunction with the Sun and stays retrograde till it reaches the point of Greatest Western Elongation. It starts to slow down just before this point and stations direct just after it It remains direct back through to the superior conjunction.

The mechanisms are the same for all the superior planets (with the exception of Mars mentioned above) and for both the inferior planets. However the timing of these periods varies according to the planets distance from the Sun

For the inferior planets, the inferior conjuctions depend on the relative movements of Earth and planet. Mercury completes an orbit of the Sun in 88 days and reaches the inferior conjunction every 116 days (allowing for the movement of Earth). This means that Mercury has three retrograde cycles in a period of around 13 months, For Venus which has an orbital period of 225 days, the inferior conjunction only occurs ever 584 days, meaning that Venus only has one retrograde period during a period of 18 months. Mercury is retrograde for between 20-24 days, three times a year, Venus is retrograde for 40-43 days every 18 months.

For the outer planets the retrograde period occurs in the period either side (and including) the opposition with the Sun as seen from Earth Generally the further from Earth the planet is, the greater the period of time in which it appears retrograde during a year. So Mars is retrograde for 58-81 days per year, Jupiter for 4 months per year, Saturn 4.5 months, Uranus 155 days, Neptune 158 days and Pluto 160 days.

 

[MareSaturni]

Minderwiz, thank you for your very comprehensive explanation.
This site complements what you said with some very cool pictures and animations!

The subject is SO fascinating! I always said that if I had been born with a bit more of a mathematical mind, I'd have studied Astronomy.

I also think it's interesting how these things are visible in a chart. I wonder if a planet moving 'slow' or 'fast'... or the fact it's appearing stationary before going retrograde or direct... has any influence on the interpretation of the chart. Surely even some ancient astrologers must have noticed this different in speed and movement, specially for closer planets, like Mercury and Venus?