<p>Due to Earth's axial precession, the vernal equinox gradually travels westward, completing a cycle in roughly 26,000 years, i.e. about 1º every 72 years. Currently, the vernal equinox crosses the ecliptic in Pisces, near its border with Aquarius. In the year 6500, i.e. in 4500 years, it will have moved a further
$$
4500\,\mathrm{yr} \,\, \times \,\, \frac{360º}{26\,000\,\mathrm{yr}} \simeq 62º,
$$
that is, to the point that currently has a right ascension of roughly 20 hours. From the map below (from <a href="https://en.wikipedia.org/wiki/First_Point_of_Aries" rel="nofollow noreferrer">Wikipedia</a>), you can see that it will just have moved out of Capricornus and into Sagittarius.</p>

<p><a href="https://i.sstatic.net/mTtzv.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mTtzv.jpg" alt="VE"></a></p>

<p>As @barrycarter made me aware, my first drawing was wrong. Today, the vernal equinox in this map is a vertical line in the right-most edge of the map, going from Polaris in Ursa Minor and through Cepheus, Cassiopeia, etc., down to the Octans. However, due to the precession this map will become distorted, and Polaris will no longer be the Northern Star; instead the axis of Earth will travel roughly along the green line, in the year 6500 lying somewhere in the middle of Cepheus. The Vernal Equinox will lie roughly along the red line, going from Cepheus through Cygnus, Vulpecula, Aquila to Sagittarius.</p>

<p>I drew this line using <a href="http://stellarium.org/" rel="nofollow noreferrer">Stellarium</a>, setting the date to 6500-01-01, switching on equatorial grid of that date and today, and using the orthographic view. My line on the southern sky may be a somewhat imprecise, but on the northern it should be fine.</p>

CC BY-SA 3.0
2016-11-18T22:24:43.570Z
@barrycarter: Yes, of course, you're right, I hadn't thought of that. However, this doesn't change where the V.E. moves across the map at the zodiac, so it is still true that the V.E. will just have moved into the Sagittarius in 4500 years from now (not 2500, as I wrote).
pela
CC BY-SA 3.0
2016-11-18T22:25:25.527Z
@DrChuck: Thanks for spotting that. The result is correct, but I wrote the wrong year.
pela
CC BY-SA 3.0
2016-11-19T23:18:38.500Z
@barrycarter: Understandable, I like your answer better.
pela
CC BY-SA 3.0
2016-11-18T11:31:35.040Z
2016-11-21T13:21:51.773Z
2016-11-21T13:21:51.773Z
pela
<p>My question is basically asking how the vernal equinox changes with time, and how we can track where it will be at certain points in time. </p>

CC BY-SA 3.0
2016-11-18T13:53:49.920Z
In 4500 years, some of the constellations are going to look rather different than they do today.  Those dang galaxies and stars keep moving!
Carl Witthoft
<coordinate>
What zodiac constellation will the Vernal Equinox be directed towards in ~6500?
J Rothschild
# What zodiac constellation will the Vernal Equinox be directed towards in ~6500?

(Asked by: username_0 on 2016-11-18)

My question is basically asking how the vernal equinox changes with time, and how we can track where it will be at certain points in time.

**Tags:** coordinate
> **Comments:**
> **username_1**: In 4500 years, some of the constellations are going to look rather different than they do today.  Those dang galaxies and stars keep moving!  

---

## 1 answers

### Answer by username_2 on 2016-11-18. Score: 3

Due to Earth's axial precession, the vernal equinox gradually travels westward, completing a cycle in roughly 26,000 years, i.e. about 1º every 72 years. Currently, the vernal equinox crosses the ecliptic in Pisces, near its border with Aquarius. In the year 6500, i.e. in 4500 years, it will have moved a further
$$
4500\,\mathrm{yr} \,\, \times \,\, \frac{360º}{26\,000\,\mathrm{yr}} \simeq 62º,
$$
that is, to the point that currently has a right ascension of roughly 20 hours. From the map below (from [Wikipedia](https://en.wikipedia.org/wiki/First_Point_of_Aries)), you can see that it will just have moved out of Capricornus and into Sagittarius.

[![VE](https://i.sstatic.net/mTtzv.jpg)](https://i.sstatic.net/mTtzv.jpg)

As @barrycarter made me aware, my first drawing was wrong. Today, the vernal equinox in this map is a vertical line in the right-most edge of the map, going from Polaris in Ursa Minor and through Cepheus, Cassiopeia, etc., down to the Octans. However, due to the precession this map will become distorted, and Polaris will no longer be the Northern Star; instead the axis of Earth will travel roughly along the green line, in the year 6500 lying somewhere in the middle of Cepheus. The Vernal Equinox will lie roughly along the red line, going from Cepheus through Cygnus, Vulpecula, Aquila to Sagittarius.

I drew this line using [Stellarium](http://stellarium.org/), setting the date to 6500-01-01, switching on equatorial grid of that date and today, and using the orthographic view. My line on the southern sky may be a somewhat imprecise, but on the northern it should be fine.

> **Comments:**
> **username_2**: @barrycarter: Yes, of course, you're right, I hadn't thought of that. However, this doesn't change where the V.E. moves across the map at the zodiac, so it is still true that the V.E. will just have moved into the Sagittarius in 4500 years from now (not 2500, as I wrote).  
> **username_2**: @DrChuck: Thanks for spotting that. The result is correct, but I wrote the wrong year.  
> **username_2**: @barrycarter: Understandable, I like your answer better.  

---

