Wow
FastFourierTransform, thanks for your kind words! Sorry for a long delay before reply, I was at a vacations
About your questions:
In the post you said that there is no perturbation model for the asteroids for example. We can't make an orbital integrator for the game that could operate in real time for sure but could we try to integrate in a separate program the orbits for all asteroids and then generate a file that we could download for SE so we could see the changes over millenia? I understand that this would require a lot of time, a lot of memory and doing a work that is more profitable from a scientific viewpoint than a plantarium software aproach but maybe... I'm just asking.
I am pretty sure that JPL has a data files for hundreds of asteroids which they had modelled together with planets and moons. That data files should be quite large, using them in SE would require implementation of a some disk data streaming mechanism. But I believe that you can't notice a difference in position of some asteroid modelled using DExxx or a simple Kepler orbit. Unless you are planning a space mission, or planning to use SE to make an astronomical observation. I don't think that precise asteroids ephemerides worth the effort.
What are going to be your plans for rotational models of planets? I mean, for example, are we going to see Milankovich Cycles? true polar wander? precession of the equinoxes? nutation? Could those new degrees of freedom be implemented procedurally for other planetary systems?
Yes, I am planning to implement some rotational model for Earth (there is one with a millions of years timespan), I already implemented one for the Moon (DExxx), other planets and moons (IAU). The rotations of moons probably will be reverted back to a forced tidal locking - the IAU model has too small timespan, and actually models a tidally-locked rotation anyway.
For procedural systems, the better way is to add a simple analytical precession. But I have to learn theory first, to know how to derive the equations.
Could we have tumbling asteroids? Or to say; non-principal axis rotators and erratic rotators? For example like the smaller moons of Pluto or some asteroids that have experienced recent collisions? Could that be implemented procedurally?
I am pretty sure that soon some scientific groups will derive an analytical or numerical model of the Plutonian system, then I'll add it to SE.
For procedural moons, the best solution is just an random rotation. No one will detect the deception
Can we have an oficial addon in the future with the most accurate ephemerids? If I understood correctly, you took several terms of a fourier series that has been calculated from orbital integrators for many objects but you didn't included all the smaller terms that would make the addition quite huge in terms of memory. I really want to see how the solar system changes in periods over 10.000 years or further knowing it's accurate.
The most long one is DE431, with a timespan from the year -13000 to the year +17000 and a 2 GB data file, which probably is too much for SE. Accuracy of all model is fractions of arcseconds, enough for any reasonable usage in SE. Technically, VSOP87 could model planetary motion to infinite timespan, but don't expect any realistic values outside the +/- 100,000 years interval.
Could we have in the near future included in SE the actual orbits of some space missions? For example I would love to see Cassini's intricate orbital path and see the historic flybys. With the accuracy that SE has archived for the different moons righ now that would be a really awesome experience. It would be great also to see the trajectory for New Horizons for example and get to see in advance the next flyby target.
Yes, I could implement support of the
SPICE data - I saw that some planetarium software uses it. Not sure if it supports the orientation/rotation of the object though.
Finally, even If I know this is probably imposible, could there be some sort of orbital integrator in-game that with the accuracy that a real-time calculation allows could make perturbation models for procedural systems also? It would be great to see precession of the orbits of procedural exomoons or changes in accentricity in the orbits of some planets due to resonant features (but I know this would get SE in the realms of the Universe Sandbox capabilities, something you aren't currently engaging on)
In real time you will have an analog of the Universe sandbox. To simulate 1000 objects with a reasonable accuracy, you will be limited to a 10x to 1000x time speed. Also, the final state of the modelling system will depend of
when you came into it or started simulation. It is impossible to model the system from the beginning, so perturbation could be accumulated only from a starting point in time. This has completely no sense in terms of accuracy. This has even less sense for a procedural systems - why do you need accuracy in a system which is completely random?
The best what SE could have in the end is some analytical, periodic modelling of perturbation of a
stable orbits. Some precession, wobbling change of eccentricity and inclination. Just like rotation models.
I guess this is the right place to ask this- will the new public version of SE still use Open GL 3.3 and will it still support Win XP?
It will be able to use any version of GL - you could specify it in the config file. But 3.2 is a minimal requirement.