Satellite Pass Watch

• clear sky near dusk or dawn
• phone with location enabled or a notebook and local coordinates
• clock
• satellite pass prediction website or app
• optional binoculars for dimmer passes

1. Choose a bright visible pass such as the ISS from a predictor that uses your actual observing location.
2. Record the predicted rise direction, rise time, maximum elevation, peak time, set direction, and total visible duration.
3. Go outside a few minutes early with a clear horizon in the predicted direction and watch the satellite move against the background stars.
4. Write down or screenshot how closely the observed rise, peak, and disappearance match the published pass.

This visual shows the core geometry the experiment is testing before the real-world observation is made.

• The object rises from the predicted horizon region, moves smoothly across the sky, and disappears near the predicted set region.
• The observed timing usually stays close to the published rise, peak, and set times within ordinary observing error.
• Higher-elevation passes usually stay visible longer and are easier to track than low skim-the-horizon passes.
• The motion is consistent with a fast moving orbital object, not with a fixed tower, aircraft holding pattern, or stationary balloon.

Repeated passes with predictable timing, direction, peak elevation, and horizon-limited visibility are exactly what an orbital satellite model predicts. This is especially useful because the pass geometry can be checked directly by ordinary observers without needing access to launch providers or national space agencies.

Open a tag to see related tools, debunks, and experiments grouped by the same topic.