<p>The really simple explanation is that Venus' orbital period is 225 days. Earth's is 365 days.</p>

<p>That ratio is 13:8 (well, more accurately 12.9777777777..:8) so you can see that your complete cycle is 13 orbits of Venus to 8 of Earth, but within that cycle our view of Venus travelling round the sun gives the pretty pattern as shown in your image.</p>

<p>This <a href="http://www.youtube.com/watch?v=4cgQNUhtmHM" rel="noreferrer">YouTube video</a> is quite a nice visualisation - should make it easy to understand.</p>

CC BY-SA 3.0
2014-11-05T10:56:27.090Z
2014-11-05T10:56:27.090Z
Rory Alsop
<p>I've always been interested by the pattern within Venus' orbit around the sun. I found this image and formula of its retrograde motion in the upper right hand corner which confused me. What does it mean? can someone break this down in layman's terms?</p>

<p><img src="https://i.sstatic.net/e96UQ.jpg" alt="enter image description here"></p>

<p>Thank you</p>

CC BY-SA 3.0
2014-11-05T09:30:53.803Z
That's the formula for the Golden Ratio http://en.wikipedia.org/wiki/Golden_ratio
Joan.bdm
CC BY-SA 3.0
2014-11-08T02:11:09.613Z
@barrycarter Well not sure what is surprising about retrograde motion. Didn't know that was particularly odd for outer planets. This was more out of curiosity of mainly about mathematics involved within it's patterns.
AppleFix88
<orbit><venus>
Explanation for the mathematics behind Venus' retrograde motion
AppleFix88
# Explanation for the mathematics behind Venus' retrograde motion

(Asked by: username_0 on 2014-11-04)

I've always been interested by the pattern within Venus' orbit around the sun. I found this image and formula of its retrograde motion in the upper right hand corner which confused me. What does it mean? can someone break this down in layman's terms?

![enter image description here](https://i.sstatic.net/e96UQ.jpg)

Thank you

**Tags:** orbit, venus

> **Comments:**
> **username_1**: That's the formula for the Golden Ratio http://en.wikipedia.org/wiki/Golden_ratio  
> **username_0**: @barrycarter Well not sure what is surprising about retrograde motion. Didn't know that was particularly odd for outer planets. This was more out of curiosity of mainly about mathematics involved within it's patterns.  

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## 1 answers

### Answer by username_2 on 2014-11-05. Score: 5

The really simple explanation is that Venus' orbital period is 225 days. Earth's is 365 days.

That ratio is 13:8 (well, more accurately 12.9777777777..:8) so you can see that your complete cycle is 13 orbits of Venus to 8 of Earth, but within that cycle our view of Venus travelling round the sun gives the pretty pattern as shown in your image.

This [YouTube video](http://www.youtube.com/watch?v=4cgQNUhtmHM) is quite a nice visualisation - should make it easy to understand.


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