This study began as a candidate for the experiments — and was culled. The reason is the intake criterion itself: an experiment makes a verifiable claim about the world. This page claims nothing. It merely shows what hundreds of tracker sites can also show: which catalogued Earth-observation satellites have a location geometrically in view. That is information, not a thesis — an app, not an experiment of its own.
It remains here as an étude, because the craft holds up: orbital propagation (SGP4) runs entirely in the browser on daily-updated, committed orbital data (CelesTrak, OMM/JSON) with owner classification from McDowell’s GCAT (CC-BY 4.0). Your location never leaves the browser — nothing is stored, nothing is sent. “Line of sight possible” means elevation above 10°, “imaging geometry likely” from 35°; both are geometry, not imagery. Classified satellites are absent from the catalogue.
This page computes in your browser which Earth-observation satellites have your location in view right now — from public orbital data, with owner classification.
Your location never leaves this browser. Nothing is stored, nothing is sent — everything is computed locally.
Orbital data as of 2026-06-20T08:22:11Z · 341 satellites · CelesTrak · GCAT (J. McDowell, planet4589.org, CC-BY 4.0) · Method sheet
Open question, should this ever become an experiment of its own: It is not the view upward that is interesting, but its change — the densification of the gaze. The daily snapshot pipeline could keep a time series instead of overwriting: how quickly the orbit fills with observers, how the ratio of commercial to military shifts, year after year. That would be a measurable thesis. Until someone needs it, this remains a study.