Choose a prediction for your location
Start with NASA Spot the Station for the ISS or the observing-location settings in Heavens-Above for satellite predictions. Enter the place where you will actually observe, and check the service’s time zone. Predictions for another city can differ enough to make a short pass hard to find.
Use the ISS and Tiangong world maps here to understand where the stations are travelling. Those maps are not a substitute for a local visibility prediction. A spacecraft can be above the horizon but invisible because it is in Earth’s shadow or because your sky is too bright.
Read direction and elevation together
A pass prediction usually gives the direction where the satellite appears, the highest elevation and the direction where it disappears. Elevation is an angle above the horizon: 0 degrees is at the horizon and 90 degrees is directly overhead. It is not the spacecraft’s altitude in kilometres.
For an illustrative pass starting in the northwest and reaching 60 degrees, locate your northwest horizon first and leave a broad view toward the high part of the sky. A 10-degree pass is much easier for trees or buildings to hide. Choose a clear viewing location before the listed start time.
Recognise what you see
The ISS normally looks like a bright point moving steadily across the sky. It reflects sunlight rather than producing a visible beam of its own. It may fade while still above the horizon as it enters Earth’s shadow. That disappearance need not mean that the prediction was wrong.
Do not identify an object from brightness alone. Compare its direction and timing with the prediction, and consider aircraft, which can have flashing lights. Individual satellites differ in brightness, and a Starlink launch does not guarantee a conspicuous train over your location.
When a predicted pass is missed
Check the date and time zone first, then the direction and the amount of clear sky available. Cloud or haze near the horizon can hide an object even when the sky overhead looks clear. Refresh your prediction before another attempt because the orbit information used by a service can change.
Record the service, location, predicted start time and what you observed. For example, “northwest horizon blocked by trees” is useful for choosing a better pass; “the map looked close” is not enough to establish visibility. You can use the next clear, higher-elevation pass as a simpler first observation.