Every size and distance shares one scale, positions are computed live from orbital elements, and surfaces, axial tilts, spin, seasons and eclipse shadows follow the real geometry for the moment shown on the clock.
Planets follow JPL’s approximate Keplerian elements (valid 1800–2050); the Moon uses a truncated ELP-2000 series accurate to about 10″, which is what makes the eclipse shadows land where they should. Moons of other planets use JPL Horizons osculating elements for August 2026 with their catalogued sidereal periods — best within a few decades of today. Probes follow two-body trajectories from Horizons state vectors. Axial tilts and spin come from the IAU/WGCCRE pole and prime-meridian models; the sub-solar point, seasons and the rotation angle shown are computed, not illustrated. The belts are a representative population drawn from the real element distributions — individual specks are not catalogued objects. The Events list is computed from this same ephemeris, not looked up.
The Sats switch covers everything we have put into space: the six deep-space probes, which stay visible at any zoom, and 1,777 real satellites of Earth — the geostationary ring, the GPS, Galileo, GLONASS and BeiDou constellations, Iridium, a sample of Starlink, and science and weather craft — from public orbital elements, with the ISS, Hubble and Tiangong selectable by name. They appear once you are zoomed in near Earth. Positions come from the TLE mean motion plus the J2 secular drift of the node and perigee: the orbit planes hold up for years, but with no atmospheric drag modelled the along-track position is only trustworthy within a few weeks of the element epoch. Checked against an independent live ISS feed, the ground track was 21 km out half a day after epoch. Satellites are drawn as markers, not to scale — the ISS is 109 m across, about a thousandth of a pixel at these zooms. The probes — Voyager 1 and 2, Pioneer 10 and 11, New Horizons and Parker Solar Probe — follow two-body trajectories from JPL Horizons state vectors, and carry a dashed trail of where they have been.
Surface maps: Solar System Scope (CC BY 4.0), derived from NASA imagery. Stars: HYG database v4.0 (CC BY-SA), 5,070 stars to magnitude 6. Deep-sky objects: OpenNGC (CC BY-SA 4.0) — 180 galaxies, clusters and nebulae at their catalogued positions, angular sizes and position angles, drawn at a floor size so the small ones stay visible; hover one for its details. Their distances are commonly cited literature values, not from that catalogue. Orbits: JPL SSD planetary elements, JPL Small-Body Database, JPL Horizons. Satellite elements: Celestrak. Spin: IAU Working Group on Cartographic Coordinates. Small moons and asteroids have procedural surfaces. Not for navigation.