Celestia Forums

I left this simulation running, came back hours later and noticed that the original inner planet had very slowly spiralled inwards and collided with the sun. Is this correct? Seems unlikely, doesn't it? Otherwise the solar system would be unstable. :( I guess there's something odd about how you're ...

No, Celestia does no gravitational calculations. It uses the "VSOP 87 theory", which is a fairly accurate polynomial series, to calculate the positions of each of the planets at a specific time. VSOP87 is quite a bit more accurate than simple Keplerian orbits, but is more complicated to implement. ...

Celestia doesn't take gravity and such into account though does it? I have the planets in calculated orbits as you mentioned. It's just the satellites that people will be sending that cant really be precaculated, as it depends on where it is, what gravity fields are effecting it, what the user has p...

Would this trajectory computing take changing positions of the planets and their gravitational pull into consideration? Thats the main reason I've used it on the satellites, simply because the gravitational forces are constantly changing as they move through space.

Thanks Falck, that page looks like it'll come in very helpful. I figured out the problem I had before. I was using sin(i) to calculate the 3d position, forgetting 'i' was in degrees and not radians. I sorted that out and it seems to be working pretty good :D. I've just run into a new problem though ...

I dunno if anyones followed the tutorial at http://www.stjarnhimlen.se/comp/ppcomp.html I've come up with the code ( http://catpee.net/orbit_calculation.txt ): double N, i, d, w, a, e, M, E, E0, E1, xv, yv, v, r; //Calculate the day number from 2000 d = astro_day(add_year, add_month, add_day, add_ho...

It's probably reasonable to simplify the orbital calculations by using Keplerian elements. Celestia has them for quite a few of the major solar system bodies in solarsys.ssc. Some links to introductory space flight information (tutorials, etc) are available at http://www.lns.cornell.edu/~seb/celest...

Wow I had forgotten I posted this a week or so after I'd posted (no one had replied so I figured no one would). I'm interested to see how you will go about this, as I work in mission analysis. On personal preference, I would use our solar system, at least as a start. Perhaps your game could do a pro...

I've posted before about the making of my game project. So far I've gotten all the physics and such pretty much completed and I'm on to creating the actual content. I'm thinking of making it a mission-planning style game, where the player gets to design probes/satellites/etc, plot their paths and fi...

Hey all. I've been working on a small gravity simulation recently for a game demo and I've kinda run into a brick wall. I'm not sure where else to ask and I've been a fan of celestia for a while now so I figured maybe someone from here would know. I've never taken physics or astrophysics at college/...