ORBITAL GEOMETRY

Every point in the scene is a real satellite or piece of debris, placed from the orbital elements NORAD published for it and advanced in time while you watch.

Reading element set

SOURCE

Positions come from Celestrak's GP element sets — the public catalogue derived from US Space Force tracking. Celestrak refreshes it every two hours and refuses a download when nothing has changed since your last one, so the visualizer keeps the last set it received and says so in the header when it is showing that instead of a fresh one.

Provider: Celestrak — GP element sets, GROUP=active
Format: JSON mean elements (OMM field names)
Refreshed: Every 2 hours at the source
Delivery: Same-origin edge proxy, trimmed to the eight fields the renderer needs, cached 6 hours
If unreachable: Last successful snapshot — or the one shipped with the deploy — labelled ARCHIVED FEED with its timestamp. The live feed is refreshed in the background, so it is never something you wait for

PROPAGATION

Each object's mean motion gives its semi-major axis; from there the draw loop advances mean anomaly and places the object on a circular orbit tilted by its inclination and node. It is a fast approximation, not an SGP4 propagator — good enough to show the shape of the constellations, not good enough to point an antenna.

Semi-major axis: a = (μ / n²)^1/3
Constants: μ = 398 600.4418 km³/s² · Earth radius 6 371 km
Orbit model: Circular approximation — eccentricity is read from the feed and shown in the dossier, but ignored while drawing
Time base: Real time, or ×50 / ×500 acceleration from the speed control

RENDERING

The scene is a hand-rolled projection on a 2D canvas: the camera drifts along its own wall-clock timeline, straight through the Earth and out the other side, yawing 180° as it passes. Point size and brightness carry depth.

Engine: p5.js canvas, 60 fps target
Objects drawn: Every object in the element set — about 16,500 today
Classification: ISS · Starlink · OneWeb · GNSS · Iridium · Other, matched on object name
The globe: Coastlines, a 30° graticule and the day/night line, turned by sidereal time and lit from the real solar direction for the clock shown — so the land passes under the right satellites
Picking: Hover within 10 px for name and altitude; click for the full dossier and a Wikipedia summary

SOUND

The soundtrack is generated, not played back — there are no audio files. Notes are drawn at random from one pentatonic scale over a filtered noise bed, so it never repeats and never resolves. It stays silent until you start it.

Scale: E♭ minor pentatonic, five pitches
Voices: Pink-noise atmosphere under a drifting low-pass, 100 Hz phantom bass, sine polysynth
Density: Quarter-note grid, 35% chance of a note, 2–6 s tails
Engine: Tone.js Web Audio graph, started by your click

LIMITS

Not an operational tracking tool. Positions are approximate and the element set may be hours old — do not use them for conjunction analysis, observation planning, or anything with a consequence.

There are no accounts, and nothing you do here is saved. The page requests the element set and, when you open a satellite, its summary from Wikipedia. Page views are counted by Cloudflare Web Analytics, which measures traffic in aggregate rather than following individuals.