<p>Generally you use celestial coordinates, which are analogous to longitude and latitude, but instead use right ascension and declination. Right Ascension uses hours, minutes, and seconds, and Declination uses degrees, minutes, and seconds. Longitude and latitude are the same no matter where you are on the Earth. If you are at the North Pole, then the coordinates of New York City are the same as if you were standing in Beijing. However, with celestial coordinates it changes based on where you are, but the difference is very very small if you stay within the solar system and nearby stars. The difference gets larger when you are far away from our Sun, so generally you would need to declare a reference frame. For example, the location of Sirius from the Earth would be different than the location of Sirius from...say...Polaris. Also, due to the proper motion of the stars and the Milankovitch cycles (notably axial tilt), the coordinates would need to be updated every 50 or so years.</p>

<p>On the ISS, they use North, South, East, and West (they predefined where those pointed), and they also use Zenith and Nadir for the up and down directions, since you can move in three dimensions.</p>

CC BY-SA 4.0
2018-10-08T20:46:49.503Z
2018-10-08T20:46:49.503Z
User24373
<p>There are a bunch of different measurements for celestial coordinates, but in regards to the solar system - or specifically the Sun as its "master" - there's the <a href="https://en.wikipedia.org/wiki/Ecliptic_coordinate_system#Primary_direction" rel="nofollow noreferrer">ecliptic celestial coordinate system</a>.</p>

<p>In that system, centred around the sun and our solar system by extension, the North pole is in the constellation Draco. According to <a href="https://en.wikipedia.org/wiki/Orbital_pole" rel="nofollow noreferrer">Wikipedia</a>, the coordinates from Earth are right ascension 18h 0m 0.0s (exact), declination +66° 33′ 38.55″.</p>

<p><a href="https://i.sstatic.net/WbrK7.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/WbrK7.png" alt="Ecliptic"></a></p>

<p><a href="https://en.wikipedia.org/wiki/File:Ecliptic_grid_globe.png" rel="nofollow noreferrer">Source</a></p>

CC BY-SA 4.0
2018-10-08T22:13:44.637Z
Actually, I am more interested in the horizontal directions. So, my "North" would be toward the vernal equinox. Anyway, are there any official labels for the six cardinal directions?
posfan12
CC BY-SA 4.0
2018-10-10T12:22:59.143Z
@posfan12 There is a coordinate system for the solar system, and if there was a "North" it would probably be called $\mathbf{\hat{z}}$; the normal vector in the $+z$ direction. If you would like to call $\mathbf{\hat{x}}$ "North"(or South)  that's okay, but in a Stack Exchange answer it's best to stick to standard, established terminology so as not to confuse future readers.
uhoh
CC BY-SA 4.0
2018-10-10T15:31:29.207Z
[Is the representation of Earth oriented correctly in this image?](https://earthscience.stackexchange.com/q/15295/6031) It seems to be.
uhoh
CC BY-SA 4.0
2018-10-08T05:42:58.507Z
2018-10-08T15:18:42.373Z
2018-10-08T15:18:42.373Z
Kyle
<p>Does the solar system also have cardinal directions? Which one is North and in what direction does it point?</p>

CC BY-SA 4.0
2018-10-08T15:16:21.750Z
https://en.wikipedia.org/wiki/Ecliptic_coordinate_system#Primary_direction
uhoh
<solar-system>
Cardinal directions in solar system?
posfan12
# Cardinal directions in solar system?

(Asked by: username_0 on 2018-10-08)

Does the solar system also have cardinal directions? Which one is North and in what direction does it point?

**Tags:** solar-system

> **Comments:**
> **username_1**: https://en.wikipedia.org/wiki/Ecliptic_coordinate_system#Primary_direction  

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## 2 answers

### Answer by username_3 on 2018-10-08. Score: 4 | Accepted answer

There are a bunch of different measurements for celestial coordinates, but in regards to the solar system - or specifically the Sun as its "master" - there's the [ecliptic celestial coordinate system](https://en.wikipedia.org/wiki/Ecliptic_coordinate_system#Primary_direction).

In that system, centred around the sun and our solar system by extension, the North pole is in the constellation Draco. According to [Wikipedia](https://en.wikipedia.org/wiki/Orbital_pole), the coordinates from Earth are right ascension 18h 0m 0.0s (exact), declination +66° 33′ 38.55″.

[![Ecliptic](https://i.sstatic.net/WbrK7.png)](https://i.sstatic.net/WbrK7.png)

[Source](https://en.wikipedia.org/wiki/File:Ecliptic_grid_globe.png)

> **Comments:**
> **username_0**: Actually, I am more interested in the horizontal directions. So, my "North" would be toward the vernal equinox. Anyway, are there any official labels for the six cardinal directions?  
> **username_1**: @username_0 There is a coordinate system for the solar system, and if there was a "North" it would probably be called $\mathbf{\hat{z}}$; the normal vector in the $+z$ direction. If you would like to call $\mathbf{\hat{x}}$ "North"(or South)  that's okay, but in a Stack Exchange answer it's best to stick to standard, established terminology so as not to confuse future readers.  
> **username_1**: [Is the representation of Earth oriented correctly in this image?](https://earthscience.stackexchange.com/q/15295/6031) It seems to be.  

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### Answer by username_2 on 2018-10-08. Score: 3

Generally you use celestial coordinates, which are analogous to longitude and latitude, but instead use right ascension and declination. Right Ascension uses hours, minutes, and seconds, and Declination uses degrees, minutes, and seconds. Longitude and latitude are the same no matter where you are on the Earth. If you are at the North Pole, then the coordinates of New York City are the same as if you were standing in Beijing. However, with celestial coordinates it changes based on where you are, but the difference is very very small if you stay within the solar system and nearby stars. The difference gets larger when you are far away from our Sun, so generally you would need to declare a reference frame. For example, the location of Sirius from the Earth would be different than the location of Sirius from...say...Polaris. Also, due to the proper motion of the stars and the Milankovitch cycles (notably axial tilt), the coordinates would need to be updated every 50 or so years.

On the ISS, they use North, South, East, and West (they predefined where those pointed), and they also use Zenith and Nadir for the up and down directions, since you can move in three dimensions.


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