<p>I'm trying to understand what exactly causes lunar nodal precession.</p>
<p>Based on <a href="https://en.wikipedia.org/wiki/Lunar_precession" rel="nofollow noreferrer">this article</a>, my understanding is that precession of the plane of the moon's orbit is what causes the motion of the Moon's nodes along the ecliptic. Is this a correct understanding? Thinking more deeply about it, it seems that Apsidal precession could also impact the location of the nodes, but I would imagine this motion would have a smaller effect.</p>
<p><a href="https://i.sstatic.net/wrsxH.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/wrsxH.gif" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2024-03-27T20:56:37.173Z
From [my answer](https://astronomy.stackexchange.com/a/40923/16685), "The torque caused by the Earth trying to pull the Moon into an equatorial orbit causes the nodal precession". Robjohn has some nice anims of nodal precession [here](https://astronomy.stackexchange.com/a/47674/16685).
PM 2Ring
CC BY-SA 4.0
2024-03-27T21:01:01.007Z
We normally consider the Moon's nodal and apsidal precessions separately. They have different periods, and opposite rotation directions.
PM 2Ring
CC BY-SA 4.0
2024-03-28T14:13:26.090Z
Thanks for the helpful responses @PM2Ring! After reviewing these links, what I'm not quite following yet is why the torque caused by the Earth trying to pull the Moon into an equatorial orbit would lead to *periodic motion* - is there something I’m missing? My understanding after reviewing Robjohn’s animations is that the earth’s torque causes the plane of the lunar orbit to basically wobble, leading to nodal precession - is that a fair characterization? Thanks again!
Stephen W.
CC BY-SA 4.0
2024-03-28T14:45:34.907Z
Yes, that's fair. The Earth-Moon system orbiting around the EMB (Earth-Moon barycentre) precesses like a gyroscope. I have more info & diagrams here:  https://astronomy.stackexchange.com/a/47503/16685
PM 2Ring
<the-moon><solar-eclipse>
What Exactly Causes Lunar Nodal Precession?
Stephen W.
# What Exactly Causes Lunar Nodal Precession?

(Asked by: username_0 on 2024-03-27)

I'm trying to understand what exactly causes lunar nodal precession.

Based on [this article](https://en.wikipedia.org/wiki/Lunar_precession), my understanding is that precession of the plane of the moon's orbit is what causes the motion of the Moon's nodes along the ecliptic. Is this a correct understanding? Thinking more deeply about it, it seems that Apsidal precession could also impact the location of the nodes, but I would imagine this motion would have a smaller effect.

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

**Tags:** the-moon, solar-eclipse

> **Comments:**
> **username_1**: From [my answer](https://astronomy.stackexchange.com/a/40923/16685), "The torque caused by the Earth trying to pull the Moon into an equatorial orbit causes the nodal precession". Robjohn has some nice anims of nodal precession [here](https://astronomy.stackexchange.com/a/47674/16685).  
> **username_1**: We normally consider the Moon's nodal and apsidal precessions separately. They have different periods, and opposite rotation directions.  
> **username_0**: Thanks for the helpful responses @username_1! After reviewing these links, what I'm not quite following yet is why the torque caused by the Earth trying to pull the Moon into an equatorial orbit would lead to *periodic motion* - is there something I’m missing? My understanding after reviewing Robjohn’s animations is that the earth’s torque causes the plane of the lunar orbit to basically wobble, leading to nodal precession - is that a fair characterization? Thanks again!  
> **username_1**: Yes, that's fair. The Earth-Moon system orbiting around the EMB (Earth-Moon barycentre) precesses like a gyroscope. I have more info & diagrams here:  https://astronomy.stackexchange.com/a/47503/16685  

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