Hill Sphere Radius

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Garyw
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Hill Sphere Radius

Post #1by Garyw » 09.03.2020, 10:28

I've been looking at the hill sphere radius calculations and I wondered if there was any way of displaying the hill sphere radius of a planet and/or moon in Celestia?

Is there a celx for this?

Thanks!!

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Lafuente_Astronomy
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Post #2by Lafuente_Astronomy » 09.03.2020, 13:21

Garyw wrote:I've been looking at the hill sphere radius calculations and I wondered if there was any way of displaying the hill sphere radius of a planet and/or moon in Celestia?

Is there a celx for this?

Thanks!!

That would be a great idea to implement. Although I think it may have been implemented already.
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selden
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Post #3by selden » 09.03.2020, 16:01

One way to do it is to draw the outline of a sphere which consists only of lines instead of solid facets.

The attached Hill_sphere.zip shows the Earth's Hill sphere using a plain-text ASCII CMOD mesh. You can modify its colors using your favorite text editor.

Hill_sphere.zip
includes "grid_sphere.cmod"
(111.75 KiB) Downloaded 22 times


capture_002_09032020_114856.png
Earth's Hill sphere using a spherical grid


Edited to add: Of course, the actual "Hill sphere" isn't really a sphere at all, since it's affected by the gravitational fields of other nearby bodies, like the Moon. *shrug*
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Topic author
Garyw
Posts: 4
Joined: 10.02.2020
With us: 8 months 10 days

Post #4by Garyw » 12.03.2020, 00:06

Thanks, that's an interesting way of doing it and yes, I realise that there are other things that affect the true hill sphere radius but this was just for a quick and dirty demo about what the hill sphere is and why it matters.


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