<p>I am constructing a fictional solar system and want to be able to calculate astronomical events and locations, like lunar phases and eclipses, plus the positions of other astronomical bodies in the sky of the inhabited planet. Is there any software that will let me plug in information (like the mass, orbital period, rotational period, axial tilt, and so on) about the star, planets, and moons, and from that get the positions and phases over time from a chosen perspective?</p>
<p>I'd like it to take into account accurate orbital motion and the effects of relativity and all of that, and give results over hundreds of simulated years.</p>
<p>I've searched online without any luck, and programming it myself seems like a very daunting task that I have no idea how to even approach. Does something like this exist?</p>

CC BY-SA 4.0
2021-08-02T19:52:31.663Z
What do you mean when you say that you are constructing a fictional solar system? Are you just asking whether there is already some available software that complies all these requirements?
Prallax
CC BY-SA 4.0
2021-08-02T19:58:12.493Z
@Prallax I am working on developing a story that takes place on a fictional planet in a fictional solar system, with some characters who are astronomers, and I want to include astronomical events in the story. I'd like to be able to simulate the solar system to set up the history of astronomical events within the fictional world.
Lawton
CC BY-SA 4.0
2021-08-02T20:07:05.047Z
Have you considered Celestia? It is based on the real solar system, but you can enter fictional solar systems as well, using plugins. It allows you to look at the solar system from any perspective at any point in time. It is not an N body simulation, tough, the orbits are precomputed
Prallax
CC BY-SA 4.0
2021-08-02T20:55:27.727Z
@Prallax it looks promising and I will certainly look into it, but I do want something that is able to simulate orbits based on the information I "know" about my astronomical objects. Thank you for the suggestion!
Lawton
CC BY-SA 4.0
2021-08-02T21:24:11.793Z
Have you seen the [worldbuilding.se] site, since this might have some relevance there too.
James K
CC BY-SA 4.0
2021-08-02T21:28:46.320Z
Though I have one observation: for the kind of application you have, you don't need to use n-body simulation and relativity. Kepler's orbits are accurate down to a fraction of a degree.
James K
CC BY-SA 4.0
2021-08-02T23:47:02.393Z
Related question by the OP on Physics.SE: https://physics.stackexchange.com/q/656702/123208
PM 2Ring
CC BY-SA 4.0
2021-08-02T23:49:45.813Z
@JamesK Sure, although a plain Kepler orbit for the Moon isn't great for predicting eclipses (assuming the OP's custom solar system has an Earthlike planet with a Moonlike moon).
PM 2Ring
CC BY-SA 4.0
2021-08-03T01:00:40.527Z
@PM2Ring I am indeed planning an Earthlike planet and a mostly Moonlike moon. The moon will probably be a little smaller in the sky, so there won't be any total solar eclipses, but there will be annular eclipses.
Lawton
CC BY-SA 4.0
2021-08-03T03:18:11.950Z
See [questions tagged `universe-sandbox`](https://astronomy.stackexchange.com/questions/tagged/universe-sandbox) and their answers. This may be close to what you need, though I'm not sure it handles any relativistic effects yet. In 2018 it seems that it didn't, but it should be revisited.
uhoh
CC BY-SA 4.0
2021-08-03T09:51:33.577Z
Also check out http://spaceengine.org/
Aaron F
<orbital-mechanics><software><moon-phases><modeling>
Is there software that will let me calculate things like lunar phases and the position of bodies in the sky in a custom solar system?
Lawton
# Is there software that will let me calculate things like lunar phases and the position of bodies in the sky in a custom solar system?

(Asked by: username_0 on 2021-08-02)

I am constructing a fictional solar system and want to be able to calculate astronomical events and locations, like lunar phases and eclipses, plus the positions of other astronomical bodies in the sky of the inhabited planet. Is there any software that will let me plug in information (like the mass, orbital period, rotational period, axial tilt, and so on) about the star, planets, and moons, and from that get the positions and phases over time from a chosen perspective?

I'd like it to take into account accurate orbital motion and the effects of relativity and all of that, and give results over hundreds of simulated years.

I've searched online without any luck, and programming it myself seems like a very daunting task that I have no idea how to even approach. Does something like this exist?

**Tags:** orbital-mechanics, software, moon-phases, modeling

> **Comments:**
> **username_1**: What do you mean when you say that you are constructing a fictional solar system? Are you just asking whether there is already some available software that complies all these requirements?  
> **username_0**: @username_1 I am working on developing a story that takes place on a fictional planet in a fictional solar system, with some characters who are astronomers, and I want to include astronomical events in the story. I'd like to be able to simulate the solar system to set up the history of astronomical events within the fictional world.  
> **username_1**: Have you considered Celestia? It is based on the real solar system, but you can enter fictional solar systems as well, using plugins. It allows you to look at the solar system from any perspective at any point in time. It is not an N body simulation, tough, the orbits are precomputed  
> **username_0**: @username_1 it looks promising and I will certainly look into it, but I do want something that is able to simulate orbits based on the information I "know" about my astronomical objects. Thank you for the suggestion!  
> **username_2**: Have you seen the [worldbuilding.se] site, since this might have some relevance there too.  
> **username_2**: Though I have one observation: for the kind of application you have, you don't need to use n-body simulation and relativity. Kepler's orbits are accurate down to a fraction of a degree.  
> **username_3**: Related question by the OP on Physics.SE: https://physics.stackexchange.com/q/656702/123208  
> **username_3**: @JamesK Sure, although a plain Kepler orbit for the Moon isn't great for predicting eclipses (assuming the OP's custom solar system has an Earthlike planet with a Moonlike moon).  
> **username_0**: @PM2Ring I am indeed planning an Earthlike planet and a mostly Moonlike moon. The moon will probably be a little smaller in the sky, so there won't be any total solar eclipses, but there will be annular eclipses.  
> **username_4**: See [questions tagged `universe-sandbox`](https://astronomy.stackexchange.com/questions/tagged/universe-sandbox) and their answers. This may be close to what you need, though I'm not sure it handles any relativistic effects yet. In 2018 it seems that it didn't, but it should be revisited.  
> **username_5**: Also check out http://spaceengine.org/  

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## 0 answers

