ISS Pass Predictor
The International Space Station crosses the sky like a bright, fast-moving star. Enter your town to get the next visible passes over the coming days, computed from live orbital data for your exact location.
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Why is the ISS only visible at dawn and dusk?
You can only see the International Space Station when it is sunlit while your sky is dark. That happens in the hours after sunset and before sunrise: the Sun is below your horizon, but the ISS is still high enough to catch sunlight. In the middle of the night it passes through Earth's shadow and stays invisible.
What does the ISS look like in the sky?
It looks like a very bright, steady white star gliding smoothly across the sky over several minutes. Unlike aircraft it does not blink and has no coloured lights. At its brightest it can outshine almost everything except the Moon and Venus.
How long does a pass last?
A typical visible pass lasts two to six minutes. The station rises from one horizon, climbs to a maximum elevation, and then sinks toward the opposite side, often fading out partway across as it enters Earth's shadow.
What does the maximum elevation mean?
Maximum elevation is how high above the horizon the ISS gets during a pass, measured in degrees. 0 degrees is the horizon and 90 degrees is straight overhead. Passes above about 40 degrees are easy to spot; very low passes can be hidden by buildings, trees, or haze.
How accurate are these predictions?
The predictions use the latest orbital data (a TLE) from CelesTrak and standard orbit propagation, so timing is usually accurate to within a minute or so for the next day. Predictions further out are less precise because the orbit changes slightly. Refresh the tool on the day you want to observe for the best accuracy.