<p>The first few diagrams show the lunar nodes coinciding with the first and last quarter phases, which is only the case every 173 days or so.
When the nodes are aligned with the new and full phases, eclipses can occur:</p>
<p><img src="https://i.sstatic.net/E3Cdt.png" alt="Earth and Moon orbits" /></p>
<p>In this diagram from <a href="https://www.timeanddate.com/eclipse/total-lunar-eclipse.html" rel="nofollow noreferrer">timeanddate.com</a>,
our point of view is north of the ecliptic, the ascending node ☊ is in the 5 o'clock direction, and the descending node ☋ is in the 11 o'clock direction.
<a href="https://en.wikipedia.org/wiki/Lunar_precession#Nodal_precession" rel="nofollow noreferrer">Nodal precession</a> moves them retrograde (clockwise from north) about 19.4° per year, an 18.6 year cycle <a href="https://en.wikipedia.org/wiki/Lunar_theory#Solar_perturbation_of_lunar_motion" rel="nofollow noreferrer">mostly due</a> to the Sun's gravity.</p>

CC BY-SA 4.0
2020-12-24T16:51:53.777Z
2020-12-24T16:51:53.777Z
Mike G
<p>. In astronomy (as opposed to astrology, a <em>pseudoscience</em> which was often proven wrong), we don’t talk about “north” and “south” nodes, but about “ascending” and “descending” nodes.</p>
<p>. The first two images and the fourth one show the Earth’s orbit as too tight a curve; this is what makes you have a hard time understanding. Since they come from astrology-related sources, I’m not surprised they can’t be trusted.</p>
<p>. The ascending node is the place where the Moon crosses the apparent yearly path of the Sun (the “ecliptic”) from the south to the north; the descending node is where the Moon crosses the ecliptic from the north to the south. This is the <em>only</em> proper definition.</p>
<p>. As JohnHoltz correctly stated, the intersection of two planes is a line, so ascending and descending nodes are indeed at 180° from each other indeed, as the third, fifth, and sixth images show. (Actually, the difference is <em>not exactly</em> 180°, because gravitational perturbations make the orbit, an ellipse rather than a circle, slowly turn with respect to the fixed stars. Hence, the line of nodes makes a full 360° turn in about 18.61 years. By the time the Moon reaches the next node, it has thus advanced a little [by about 1.5°, from a quick calculation]).</p>

CC BY-SA 4.0
2020-12-23T05:56:09.980Z
How did you calculate 18.61 years? Can you explain that? that is very interesting.
Majoris
CC BY-SA 4.0
2020-12-24T01:26:12.957Z
Well, *I* did *not* calculate it; it comes from Wikipedia and many other sources. https://en.wikipedia.org/wiki/Lunar_node
(I’m sure there *is* a way to calculate it, but there’s no room for that in a comment.)
Pierre Paquette
CC BY-SA 4.0
2020-12-23T05:45:40.177Z
2020-12-23T05:45:40.177Z
Pierre Paquette
<p>What is the correct concept of the North node and South node? There is some conflicting information on the internet.</p>
<p>Which one of these two is correct?</p>
<p><strong>1. Sourced from some Astrology material</strong> - How can North and South be 180-degree opposites in this since these are on one side of the orbit curve?</p>
<p><a href="https://astrologyquestionsandanswers.com/2016/10/12/major-and-minor-chords-the-moons-nodes-part-two/" rel="nofollow noreferrer">https://astrologyquestionsandanswers.com/2016/10/12/major-and-minor-chords-the-moons-nodes-part-two/</a></p>
<p><a href="https://i.sstatic.net/lbPhM.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/lbPhM.jpg" alt="enter image description here" /></a></p>
<p><a href="https://www.spiritdaughter.com/blogs/align-with-magic/a-shift-in-perspective-the-north-node-moves-to-gemini" rel="nofollow noreferrer">https://www.spiritdaughter.com/blogs/align-with-magic/a-shift-in-perspective-the-north-node-moves-to-gemini</a></p>
<p><a href="https://i.sstatic.net/QumSF.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/QumSF.jpg" alt="enter image description here" /></a></p>
<p><a href="http://astrologyclub.org/eclipses-and-the-moons-nodes/" rel="nofollow noreferrer">http://astrologyclub.org/eclipses-and-the-moons-nodes/</a></p>
<p><a href="https://i.sstatic.net/eRf3a.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/eRf3a.gif" alt="enter image description here" /></a></p>
<p><a href="https://i.sstatic.net/zIG5i.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/zIG5i.gif" alt="enter image description here" /></a></p>
<p><strong>2.From Wikipedia source</strong> - This seems incorrect too since there is no &quot;separate&quot; Moon orbit as per around the Sun</p>
<p><a href="https://en.wikipedia.org/wiki/Lunar_node" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Lunar_node</a>
<a href="https://i.sstatic.net/aObdX.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/aObdX.png" alt="enter image description here" /></a></p>
<p><a href="http://www.antidotebrooklyn.com/celeste-blog/2019/4/21/riding-the-tail-of-the-celestial-dragon" rel="nofollow noreferrer">http://www.antidotebrooklyn.com/celeste-blog/2019/4/21/riding-the-tail-of-the-celestial-dragon</a>
<a href="https://i.sstatic.net/mO5vq.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mO5vq.png" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2020-12-23T03:57:21.497Z
Hi. Can you provide links to the original figures? There may be some description that clarifies them.
JohnHoltz
CC BY-SA 4.0
2020-12-23T03:59:03.590Z
The first figure uses a lot of "artistic license". If we are to assume that the portion of the Moon's orbit that goes "over the top of the Earth" is the portion above the ecliptic plane, then the North and South nodes are labeled correctly. They should be 180 degrees apart because the intersection of 2 planes is a straight line.
JohnHoltz
CC BY-SA 4.0
2020-12-23T03:59:34.923Z
The second figure has the symbols for ascending and descending nodes reverses, but is otherwise reasonable except that the two nodes are not 180 degrees apart.
JohnHoltz
CC BY-SA 4.0
2020-12-23T05:29:25.090Z
@JohnHoltz Updated the question with links. If the first one is correct then the North node and the south node can not be exactly 180 opposite. If the second one is correct then the Moon doesn't have its own orbit around the Sun.
Majoris
<the-sun><orbit><the-moon><earth>
North node, South node correct understanding
Majoris
# North node, South node correct understanding

(Asked by: username_0 on 2020-12-23)

What is the correct concept of the North node and South node? There is some conflicting information on the internet.

Which one of these two is correct?

**1. Sourced from some Astrology material** - How can North and South be 180-degree opposites in this since these are on one side of the orbit curve?

<https://astrologyquestionsandanswers.com/2016/10/12/major-and-minor-chords-the-moons-nodes-part-two/>

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

<https://www.spiritdaughter.com/blogs/align-with-magic/a-shift-in-perspective-the-north-node-moves-to-gemini>

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

<http://astrologyclub.org/eclipses-and-the-moons-nodes/>

[![enter image description here](https://i.sstatic.net/eRf3a.gif)](https://i.sstatic.net/eRf3a.gif)

[![enter image description here](https://i.sstatic.net/zIG5i.gif)](https://i.sstatic.net/zIG5i.gif)

**2.From Wikipedia source** - This seems incorrect too since there is no "separate" Moon orbit as per around the Sun

<https://en.wikipedia.org/wiki/Lunar_node>
[![enter image description here](https://i.sstatic.net/aObdX.png)](https://i.sstatic.net/aObdX.png)

<http://www.antidotebrooklyn.com/celeste-blog/2019/4/21/riding-the-tail-of-the-celestial-dragon>
[![enter image description here](https://i.sstatic.net/mO5vq.png)](https://i.sstatic.net/mO5vq.png)

**Tags:** the-sun, orbit, the-moon, earth
> **Comments:**
> **username_1**: Hi. Can you provide links to the original figures? There may be some description that clarifies them.  
> **username_1**: The first figure uses a lot of "artistic license". If we are to assume that the portion of the Moon's orbit that goes "over the top of the Earth" is the portion above the ecliptic plane, then the North and South nodes are labeled correctly. They should be 180 degrees apart because the intersection of 2 planes is a straight line.  
> **username_1**: The second figure has the symbols for ascending and descending nodes reverses, but is otherwise reasonable except that the two nodes are not 180 degrees apart.  
> **username_0**: @JohnHoltz Updated the question with links. If the first one is correct then the North node and the south node can not be exactly 180 opposite. If the second one is correct then the Moon doesn't have its own orbit around the Sun.  

---

## 2 answers

### Answer by username_2 on 2020-12-24. Score: 3

The first few diagrams show the lunar nodes coinciding with the first and last quarter phases, which is only the case every 173 days or so.
When the nodes are aligned with the new and full phases, eclipses can occur:

![Earth and Moon orbits](https://i.sstatic.net/E3Cdt.png)

In this diagram from [timeanddate.com](https://www.timeanddate.com/eclipse/total-lunar-eclipse.html),
our point of view is north of the ecliptic, the ascending node ☊ is in the 5 o'clock direction, and the descending node ☋ is in the 11 o'clock direction.
[Nodal precession](https://en.wikipedia.org/wiki/Lunar_precession#Nodal_precession) moves them retrograde (clockwise from north) about 19.4° per year, an 18.6 year cycle [mostly due](https://en.wikipedia.org/wiki/Lunar_theory#Solar_perturbation_of_lunar_motion) to the Sun's gravity.


---

### Answer by username_3 on 2020-12-23. Score: 1

. In astronomy (as opposed to astrology, a *pseudoscience* which was often proven wrong), we don’t talk about “north” and “south” nodes, but about “ascending” and “descending” nodes.

. The first two images and the fourth one show the Earth’s orbit as too tight a curve; this is what makes you have a hard time understanding. Since they come from astrology-related sources, I’m not surprised they can’t be trusted.

. The ascending node is the place where the Moon crosses the apparent yearly path of the Sun (the “ecliptic”) from the south to the north; the descending node is where the Moon crosses the ecliptic from the north to the south. This is the *only* proper definition.

. As JohnHoltz correctly stated, the intersection of two planes is a line, so ascending and descending nodes are indeed at 180° from each other indeed, as the third, fifth, and sixth images show. (Actually, the difference is *not exactly* 180°, because gravitational perturbations make the orbit, an ellipse rather than a circle, slowly turn with respect to the fixed stars. Hence, the line of nodes makes a full 360° turn in about 18.61 years. By the time the Moon reaches the next node, it has thus advanced a little [by about 1.5°, from a quick calculation]).

> **Comments:**
> **username_0**: How did you calculate 18.61 years? Can you explain that? that is very interesting.  
> **username_3**: Well, *I* did *not* calculate it; it comes from Wikipedia and many other sources. https://en.wikipedia.org/wiki/Lunar_node (I’m sure there *is* a way to calculate it, but there’s no room for that in a comment.)  

---

