Default overview
The default distance scale compresses AU spacing only enough to keep Mercury through Neptune, the Sun, orbit ellipses, and labels in one study frame. Linear AU study remains available for distance inspection.
3D outer-space simulator
Fly through the Milky Way, constellations, satellites, and the solar system.
A separate WebGL study desk for galaxy context and solar-system learning: real named objects, relative planet sizes, relative AU distances, animated Sun, constellation lines, satellite catalog samples, and click-to-read planet panels.
Ctrl + wheel = fast zoom
WebGL simulator is initializing. If your browser blocks WebGL or external module loading, use the planet field guide and SkyMap pages.
Data And Scale
What is real, what is scaled
Planet-size modes
True AU + real radii mode computes Sun, planet, Moon, and Galilean-moon mesh radii from radius_km divided by AU_km against the selected AU distance scale. Glow markers and labels keep tiny real-scale objects findable without changing their physical mesh radius.
Earth and Moon model status
Earth now uses the supplied earth.glb model embedded into the 3D simulators, with atmosphere glow only and no extra cloud shell overlay. Moon now uses the supplied moon.glb model embedded into the simulator runtime, while keeping its Earth-relative orbit and synchronous rotation facts.
Planet positions
The main simulator renders the eight major planets. Ceres is a dwarf planet in the asteroid belt and is kept out of the main planet orbit layer; dwarf-planet coverage belongs in the dwarf planet pages.
Jupiter moon system
Selecting Jupiter reveals Io, Europa, Ganymede, and Callisto with Jupiter-relative orbit rings, mean orbital distances, periods, synchronous rotations, inclinations, and speed readouts.
Voyager scale
The Voyager scale compresses heliocentric AU distance enough to keep the Sun, major planetary orbit bands, Voyager 1, and Voyager 2 in one study mode. Selecting either spacecraft centers it and keeps live AU, km, km/s, and km/hr values in the information panel.
Coordinate system
Planet readouts use Sun-centered heliocentric ecliptic Cartesian coordinates in AU. X and Y lie in Earth's orbital-plane reference frame, Z is north/south of that ecliptic plane, and velocity is listed from the same vector snapshot when available.
Elliptical orbits
Orbit curves use semimajor axis, eccentricity, perihelion, and aphelion values. The Sun is plotted at one focus, not the center of a circle.
Milky Way context
The galaxy layer uses named real targets and approximate distances: Alpha Centauri, Sirius, Pleiades, Orion Nebula, galactic center, and Andromeda.
Constellations
Constellation lines use named bright-star patterns for Orion, Ursa Major, Cassiopeia, Cygnus, and Scorpius. They are selectable orientation geometry, not a local sidereal sky projection.
Satellites
The satellite layer samples same-origin catalog records and propagates selected named objects from catalog epoch fields in simplified altitude/inclination shells. ISS and Hubble show Earth-relative orbit paths and approximate speed when selected; it is not SGP4 precision tracking.
Hubble model status
Hubble uses a lightweight telescope geometry with an Earth-relative HST catalog shell until a supplied Hubble GLB is added.
Webb model status
James Webb uses the supplied telescope geometry package in the simulator and follows the same L2 study-orbit treatment used by the scene controls.
Model handling
Planet, Sun, dwarf-planet, and spacecraft assets are normalized into the site build so the public pages stay self-contained and do not expose outbound attribution panels.
Mathematical model
Keplerian space-map model
This WebGL scene is generated from orbital mechanics and catalog values, not from a visual reference image. Rendered body sizes may be deliberately bounded for readability, but positions and orbit curves follow the stated equations.
Orbit equation
\[r=\frac{a(1-e^2)}{1+e\cos(\nu)}\]
For each bound two-body orbit, semi-major axis a and eccentricity e define the conic. The rendered ellipse is mathematically correct for the selected elements after rotation into the scene frame.
Kepler propagation
\[M=n(t-\tau),\qquad M=E-e\sin(E)\]
Mean anomaly M advances linearly with mean motion n. Solving Kepler's equation gives eccentric anomaly E and true anomaly nu, so the body position is computed from time rather than hand-drawn.
Reference-frame transform
\[\mathbf{r}_{\mathrm{scene}}=R_z(\Omega)\,R_x(i)\,R_z(\omega)\,\mathbf{r}_{\mathrm{orbit}}\]
Inclination i, longitude of ascending node Omega, and argument of periapsis omega rotate the orbital-plane vector into the heliocentric scene. This proves the geometry is a coordinate transform of the orbital model.
Verification standard: the rendered object must be reproducible from stated equations, catalog parameters, or explicit geometric transforms. Visual reference images may inform presentation only; they are not the source of orbital positions, field vectors, accretion-disk gradients, timing, or engineering layout.
Limitations: browser scenes may use bounded scale, compressed distances, simplified two-body dynamics, schematic transfer curves, or educational approximations where full numerical ephemerides, CFD, finite-element models, or general-relativistic ray tracing are outside the page scope. Those simplifications are part of the model contract, not hidden image-based construction.