When can you see a satellite?
Satellites don't make their own light. You see them because they reflect sunlight, so a satellite is only visible when it's still in sunshine while you're in darkness. That happens for an hour or two after sunset and before sunrise, when the sky has darkened but a satellite a few hundred kilometres up can still see the sun. In the middle of the night most satellites are in Earth's shadow, except around midsummer at high latitudes, when the ISS can be seen several times a night. The calculator counts a pass as visible when the satellite is at least 10° up, lit by the sun, and the sun is at least 6° below your horizon.
What you'll see
The ISS looks like a very bright, steady star moving smoothly across the sky, much brighter than any star and often brighter than Venus. It takes a few minutes to cross. It doesn't flash or have coloured lights, which is how you tell it from an aircraft. A pass often ends with the station fading to orange and then vanishing well above the horizon as it enters Earth's shadow. Tiangong, China's space station, is a little fainter, and Hubble is fainter still, like an ordinary star.
Look in the direction shown under "From" at the time it appears, and follow the path on the sky chart. Higher passes are brighter because the satellite is closer.
Where the times come from
Orbit data is downloaded from CelesTrak and the passes are worked out in your browser with the SGP4 model, the standard used by tracking services. Times are typically accurate to within a minute for the next few days. The ISS fires its engines to raise its orbit from time to time, so check again close to a pass. For radio contacts with the ISS and amateur satellites, see the amateur satellite pass predictor, which includes daytime passes.
Questions
When can I see the ISS tonight?
Enter your locator above or use your device's location. The table lists every visible pass in the next few days with the time it appears, its direction and how high it gets.
Why can I only see the ISS at dawn and dusk?
It's only visible when it's lit by the sun while your sky is dark. That's usually in the couple of hours after sunset or before sunrise.
How bright is the ISS?
Very bright, often brighter than Venus, and easy to see from a city. It moves steadily without flashing.
Can I see Starlink satellites?
Newly launched Starlink satellites form a bright 'train' for a few days after launch, then raise their orbits and become much fainter. Look for recent launches in the satellite list.