Starting
Real: orbital shape (semi-major axis, eccentricity, inclination), periods, rotation, axial tilt, diameters, masses, gravity, temperatures. Visualization: distances from the Sun are compressed (display = 40 × AU0.55), body sizes are exaggerated, and moon orbits are compressed around their planet. Nothing in the 3D view is literally to scale; the Compare dialog shows true relative diameters.
Planets and Pluto use JPL J2000 Keplerian elements (E. M. Standish) advanced by mean motion and a Kepler solver, without secular rates, so accuracy declines far from the year 2000. Moons use circular orbits with arbitrary starting phases. Comets use approximate elements and a simplified visual model: tails are a heuristic particle effect, not physics. Belts are seeded visual distributions, not catalogued objects.
The eclipse view is an educational alignment, not a prediction. Distances and light times come from the simplified model at the simulated time and are approximate.
Orbital elements: NASA/JPL SSD. Physical data: NASA Planetary Fact Sheet, JPL SSD satellite tables; values rounded. Moon counts change as discoveries are confirmed.
By default every surface is generated procedurally. Real textures load only from assets/textures/ when listed in manifest.json and documented in ATTRIBUTIONS.md; any failure falls back to the procedural version. Not affiliated with NASA, ESA or JPL.
assets/textures/
manifest.json
Three.js r160 (MIT) with its EffectComposer and UnrealBloomPass add-ons, loaded from jsDelivr.