About WatchSat

WatchSat is a real-time 3D satellite tracker that propagates roughly 16,000 active satellites live from public orbital data and renders them on a physically-motivated globe.

What WatchSat does

Open the live globe and every point is a real spacecraft whose position is computed in your browser — the International Space Station, thousands of Starlink and OneWeb broadband satellites, the GPS, GLONASS, Galileo and BeiDou fleets, weather and Earth-observation satellites, and more.

How it works

Every satellite’s orbit is described by a Two-Line Element set (TLE) published by the US Space Force and distributed through CelesTrak. WatchSat feeds each TLE into the SGP4/SDP4 model to compute live position and velocity. See the FAQ and What is a TLE? for more depth.

Data sources & accuracy

Orbital data comes from CelesTrak; Earth and sky imagery from NASA, ESA and USGS. Positions are typically accurate to within a few kilometres for recently updated LEO objects. Educational visualization only — not for collision avoidance.

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