Wow FastFourierTransform, thanks for your kind words! Sorry for a long delay before reply, I was at a vacations
Thank you for your detailed responses Vladimir!! And excuse me for the delay.
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.
Ok, I understand. Maybe in the future there could be a system to directly load orbital solutions from JPL to Space Engine for spacific asteroids. SE could be a usefull tool also for planing observations.
Also I'm very happy to hear that you are going to work in rotational models for the planets, also the erratic rotators, and the SPICE integration of spacaft trajectories (that is going to be amazing in so many levels).
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.
This is understandable.
I have a few more questions:
1) Precession of Mercury's perihelion: I saw it in SE and looks great, but only occurs from the year 1550 to the 2560. Considering this is a more or less periodic phenomena could you make the timespan for the precession bigger? In that way we could see further evolution of Mercury's orbit. It's a very small angle now and If one has to explain it to people they are not going to clearly see it if it is not with longer duration.
2) When you increase the time-flow speed and end using a timescale of 10[sup]6[/sup], the orbits clearly "jump". For example if you go to Saturn and watch it from 0.5 AU with that time-flow, you can clearly see how for each step the orbit change in a discrete jump. I know this is because for each timestep you compute a new keplerian orbit. But could the timestep be smaller? or could it be interpolated for more points between one and the next orbit render so this effect get's unnoticed?
3) I saw that you have implemented TASS 1.7 for the Saturnian system; the orbital theory that acounts for the perturbations over Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion and Iapetus. Is there some solution for the rest of the moons of Saturn?
I think is important we can see for example the orbital exchange between Janus and Epimetheus.
A very interesting phenomenon that occurs every 4 years. Seen from Epimetheus how the 200 km sized Janus aproaches and then leaves swaping orbits between them it's a dream. In SE for now you just see them in opposite sides of Saturn, never coming close, never swaping orbits