<p>By definition, it is zero; the ecliptic <em>is</em> the plane of earth's orbit (or rather, the inverse: the path the Sun seems to follow along the sky).</p>

<p>But you're probably looking for variations in the <a href="https://en.wikipedia.org/wiki/Axial_tilt#Earth" rel="nofollow noreferrer">axial tilt of the Earth</a>. There's a lot of formulas in the article, and on the (astronomically speaking) short timescale of a few million years, it oscillates between 22 and 24.5 degrees with a period of about 41,000 years. See the graph below, the red dot is the year 2000:</p>

<p><a href="https://i.sstatic.net/KpyU6.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/KpyU6l.png" alt="enter image description here"></a></p>

<p><sub>(picture by Tfr000 on Wikipedia, data from Laskar (1986))</sub></p>

CC BY-SA 3.0
2018-03-29T07:19:53.840Z
2018-03-29T07:19:53.840Z
Glorfindel
<p>What does the angle between the plane of the earth's orbit and the ecliptic (now about 23.5 degrees) vary between, and over what time scale?</p>

CC BY-SA 3.0
2018-03-29T08:06:15.673Z
I think you mean the plane of Earth's equator and the ecliptic.
James K
<orbit><earth>
What does the angle between plane of earth's orbit and ecliptic vary between?
Ron Jonesa
# What does the angle between plane of earth's orbit and ecliptic vary between?

(Asked by: username_0 on 2018-03-29)

What does the angle between the plane of the earth's orbit and the ecliptic (now about 23.5 degrees) vary between, and over what time scale?

**Tags:** orbit, earth
> **Comments:**
> **username_1**: I think you mean the plane of Earth's equator and the ecliptic.  

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## 1 answers

### Answer by username_2 on 2018-03-29. Score: 3

By definition, it is zero; the ecliptic *is* the plane of earth's orbit (or rather, the inverse: the path the Sun seems to follow along the sky).

But you're probably looking for variations in the [axial tilt of the Earth](https://en.wikipedia.org/wiki/Axial_tilt#Earth). There's a lot of formulas in the article, and on the (astronomically speaking) short timescale of a few million years, it oscillates between 22 and 24.5 degrees with a period of about 41,000 years. See the graph below, the red dot is the year 2000:

[![enter image description here](https://i.sstatic.net/KpyU6l.png)](https://i.sstatic.net/KpyU6.png)

(picture by Tfr000 on Wikipedia, data from Laskar (1986))


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