Similar questions are here in Computation Science for binary stars, satellites and comets but I need to simulate several planet-size celestial bodies over long timescales (1K - 1M years) to determine stability. Asked questions related to my application on Space Exploration and Physics but haven't gotten much interest or answers. Turning here to consider researching myself.
Possibilities so far:
- ORSA sounds promising but is 10 years old, has six errors on install, and crashes. I have it showing a cute little Earth going around a cute little Sun at about 20 samples per second. It will export thousands of PNGs but not an AVI.
- ODTBX seems more for artificial satellites around Earth and may require MATLAB.
- Celestia seems more for visual rendering than long-term simulation.
- GMAT seems more for interplanetary spacecraft of a negligible mass.