Accuracy of Celestia

General discussion about Celestia that doesn't fit into other forums.
Topic author
half0
Posts: 8
Joined: 21.10.2008
With us: 15 years 8 months

Accuracy of Celestia

Post #1by half0 » 22.10.2008, 09:29

I was wanting to know how accurate this program is in multiple fields.

1.) Are all the movement of bodies (i.e. planet revolution, star rotation, ect...) accurate?
2.)Does this program take into account other things such as magnetic fields and solar flares just to name a few?
3.)Does this program use "real-time" physics? (i.e. If two asteroids collide and get thrown from orbit then would we be able to watch them from the program based on present day calculations?)

I have other questions but they stem off the questions mentioned.

Nick

BobHegwood
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Re: Accuracy of Celestia

Post #2by BobHegwood » 22.10.2008, 09:33

1) As accurately as possible.
2) As much as possible.
3) As closely as possible.
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Topic author
half0
Posts: 8
Joined: 21.10.2008
With us: 15 years 8 months

Re: Accuracy of Celestia

Post #3by half0 » 22.10.2008, 10:04

If that is the case then would anyone be able to tell me what equations are used? (not all of them, lol, Just some examples to give me an idea)

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selden
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Re: Accuracy of Celestia

Post #4by selden » 22.10.2008, 11:12

Nick,

Celestia uses ephemeides (precalculated trajectories) for most of its positions. It does not apply any realtime gravitational or other corrections for many reasons.

As shipped, Celestia uses the VSOP87 theory of planetary orbits, although the series are truncated for speed. They're good to better than a few seconds of arc as seen from the Earth for about +/- 2000 years from today.

Many of the orbits of the other solar system objects are represented only by Keplerian elipses, so they're only approximate.

Most stellar positions are taken directly from the Hipparcos catalog. Celestia v1.6 will be using the updated catalog released earlier this year.

Celestia can use JPL DE ephemerides and SPICE kernels which you provide in order to be as accurate as necessary. When that's done, it can exactly reproduce the trajectories of NASA spacecraft flybys, for example.

For more details, please read the Celestia WikiBook at
http://en.wikibooks.org/wiki/Celestia
Selden

Topic author
half0
Posts: 8
Joined: 21.10.2008
With us: 15 years 8 months

Re: Accuracy of Celestia

Post #5by half0 » 22.10.2008, 11:50

A much better answer nad the ones I was looking for. Thank you

Nick


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