What this does
Orbit's Light shows satellites passing overhead from your location using SGP4 orbital propagation. Each dot on the polar plot represents a satellite; you can filter, sort, and colorize them to analyze orbital patterns.
The sky plot (left)
- Polar Grid: North at top, South at bottom. Concentric rings show elevation angles (0°=horizon, 90°=directly overhead).
- Cardinal Directions: N, E, S, W labels mark compass directions.
- Blue Dots: Visible satellites above your elevation cutoff.
- Colored Rings: Accent-colored ring shows your minimum elevation cutoff.
- Names Toggle: Click "Names: Off/On" to show satellite names and speeds on the plot.
⚙️ Filters & Controls (Top Controls)
- Elevation Cutoff: Hides satellites below this angle (default 15°). Lower = more satellites but shorter observation windows.
- Max Altitude: Hides satellites higher than this (default 500 km). Useful for filtering out high-orbit sats.
- Refresh Now: Forces a TLE (orbit data) reload from server.
- Pause: Stops the animation to examine static positions.
- Sort: Organize satellite list by Name, Altitude, Distance (closest first), or Speed (fastest first).
- Colorize: Color satellites and list names by the selected sort metric (helpful for visual pattern spotting).
- Names: Toggle all satellite names on the sky plot.
- Night: Toggle red night-vision mode to preserve dark adaptation.
Satellite list (right)
- Click to Select: Tap any satellite to highlight it on the plot.
- Filter Box: Type a name to quickly find satellites (e.g., "ISS", "HUBBLE").
- Per-Satellite Info: Azimuth (direction), Elevation (angle), Altitude (km), Range (distance in km), Speed (angular speed in °/s).
Observer location
Shows your latitude/longitude and the nearest major city with distance and bearing. Location is detected via device GPS; you can also enter a manual latitude,longitude in the box below the location display to set a custom observer location.
Orientation note: The sky plot is displayed as if you were lying down with your head to the north and feet to the south — east appears on the left and west on the right.
Time display
Displays your local time and how long ago the TLE (orbit data) was last updated. Fresher TLEs improve prediction accuracy.
Color legend
When Colorize is on, a color scale appears showing which metric is currently mapped. On phones, the legend is horizontal below the plot. On desktop, it's centered between columns.
Tips
- Lower your elevation cutoff for more satellites (but shorter visibility windows).
- Use "Colorize" with "Sort: Altitude" to see which satellites are highest.
- Watch the speed of dots moving on the plot—slower = higher orbits, faster = lower orbits.
- Use Night mode when observing to keep your eyes dark-adapted.
- The ISS (International Space Station) is often the brightest and fastest-moving at lower altitudes.
Technical notes
Data from CelesTrak TLE updates. Predictions use SGP4 orbital propagation (accurate for about one week from TLE date). Light pollution context is provided via nearest major city bearing/distance.