<blockquote>
<p>Does this mean that the frames are rendered as if they were seen from the North Pole and the South Pole respectively?</p>
</blockquote>
<p>No. The images are how the Moon appears from Earth (technically the center of the Earth) and are rotated so that celestial north is up. The images are not looking at the Moon from above the north pole of the Moon, and they are not based on an observer at Earth's north pole (although the difference due to latitude on Earth would be small).</p>
<p>Celestial North is the direction in the sky toward Polaris. Depending on your latitude and where you are looking in the sky, celestial north can be in any direction.</p>
<p><a href="https://i.sstatic.net/BBpyz.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/BBpyz.png" alt="direction of celestial north" /></a>
Figure 1: Northern hemisphere observer looking south. The red lines are lines of right ascension; the blue lines are lines of declination. Celestial north is in the direction of Polaris and is shown in three different parts of the sky by the read arrows. Paste the image of the Moon into the figure and rotate the Moon accordingly to keep celestial north in the correct direction.</p>

CC BY-SA 4.0
2024-03-19T16:03:12.833Z
2024-03-19T16:03:12.833Z
JohnHoltz
<p>I would like to rotate the images to match the view from my window and to do this I need to know the location for which the original frames are rendered.</p>
<p>The relevant description on the page <a href="https://svs.gsfc.nasa.gov/5187/" rel="nofollow noreferrer">https://svs.gsfc.nasa.gov/5187/</a> is:</p>
<blockquote>
<p>Celestial north is up in these images, corresponding to the view from the northern hemisphere. ... (There is also a south-up version of this page.)</p>
</blockquote>
<p>Does this mean that the frames are rendered as if they were seen from the North Pole and the South Pole respectively?</p>
<p>Rotation angle can be calculated with Skyfield: <a href="https://rhodesmill.org/skyfield/examples.html#at-what-angle-in-the-sky-is-the-crescent-moon" rel="nofollow noreferrer">https://rhodesmill.org/skyfield/examples.html#at-what-angle-in-the-sky-is-the-crescent-moon</a></p>

CC BY-SA 4.0
2024-03-19T11:08:08.650Z
The NASA web site says, "The animation ... shows the **geocentric** phase, libration, position angle of the axis, and apparent diameter of the Moon ..." The "geocentric" term means the view displays the Moon as it appears if viewed from the center of the Earth. The point at the center of each frame is the point on the Moon where the Earth is directly overhead. The [celestial poles](https://en.wikipedia.org/wiki/Celestial_pole) are aligned with the Earth's rotation axis.
creidhne
<moon-phases>
Are the NASA Dial-A-Moon frames rendered as seen from the north and south poles?
Reginald
# Are the NASA Dial-A-Moon frames rendered as seen from the north and south poles?

(Asked by: username_0 on 2024-03-19)

I would like to rotate the images to match the view from my window and to do this I need to know the location for which the original frames are rendered.

The relevant description on the page <https://svs.gsfc.nasa.gov/5187/> is:

> Celestial north is up in these images, corresponding to the view from the northern hemisphere. ... (There is also a south-up version of this page.)

Does this mean that the frames are rendered as if they were seen from the North Pole and the South Pole respectively?

Rotation angle can be calculated with Skyfield: <https://rhodesmill.org/skyfield/examples.html#at-what-angle-in-the-sky-is-the-crescent-moon>

**Tags:** moon-phases

> **Comments:**
> **username_1**: The NASA web site says, "The animation ... shows the **geocentric** phase, libration, position angle of the axis, and apparent diameter of the Moon ..." The "geocentric" term means the view displays the Moon as it appears if viewed from the center of the Earth. The point at the center of each frame is the point on the Moon where the Earth is directly overhead. The [celestial poles](https://en.wikipedia.org/wiki/Celestial_pole) are aligned with the Earth's rotation axis.  

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## 1 answers

### Answer by username_2 on 2024-03-19. Score: 3

> Does this mean that the frames are rendered as if they were seen from the North Pole and the South Pole respectively?

No. The images are how the Moon appears from Earth (technically the center of the Earth) and are rotated so that celestial north is up. The images are not looking at the Moon from above the north pole of the Moon, and they are not based on an observer at Earth's north pole (although the difference due to latitude on Earth would be small).

Celestial North is the direction in the sky toward Polaris. Depending on your latitude and where you are looking in the sky, celestial north can be in any direction.

[![direction of celestial north](https://i.sstatic.net/BBpyz.png)](https://i.sstatic.net/BBpyz.png)
Figure 1: Northern hemisphere observer looking south. The red lines are lines of right ascension; the blue lines are lines of declination. Celestial north is in the direction of Polaris and is shown in three different parts of the sky by the read arrows. Paste the image of the Moon into the figure and rotate the Moon accordingly to keep celestial north in the correct direction.


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