The short answer
You can see the International Space Station with no equipment at all. It looks like a bright, steady, star-like point gliding across the sky without blinking, usually for a few minutes, in the hour or two after sunset or before sunrise. At its best it is brighter than any star, around magnitude −3 to −4, which puts it in the same league as Venus and Jupiter.
The trick is timing. The ISS isn’t visible every night from every place, and each pass lasts only minutes, so you need a prediction for your location. The ISS pass finder lists upcoming visible passes, and the ISS page shows where it is now.
Why you can see it
The station has no lights bright enough to see from the ground. What you see is sunlight reflecting off its large solar arrays and modules. It orbits roughly 400 kilometers up, going around Earth about every hour and a half.
For a pass to be visible, two things must be true together: you must be in darkness, and the station, high above you, must still be in sunlight. That only happens near dusk and dawn. In the middle of the night, the station is usually in Earth’s shadow and invisible even when it passes overhead. In daylight, the sky is too bright.
When passes happen
Visible passes come in runs. For a week or two you may get one or more passes most evenings, then a stretch with only morning passes, then a gap with none at all, before the cycle repeats. The pattern shifts because the station’s orbit slowly turns relative to the Sun.
The station’s orbit is tilted about 51.6 degrees to the equator, so it can be seen from most of the inhabited world. Around midsummer at higher latitudes, the sky never gets fully dark and the station can stay sunlit all night, which can bring several passes in a single night.
Reading a pass prediction
A typical pass prediction gives you a handful of numbers. Here’s what each means.
- Start time and direction. When and where the station rises above your horizon, for example in the west-northwest. It appears low, so a clear horizon in that direction helps.
- Maximum altitude. How high it climbs, in degrees above the horizon. 90 degrees is straight overhead. Passes above about 40 degrees are usually the brightest and easiest; low passes are dimmer and can hide behind buildings.
- Brightness. A magnitude: the more negative, the brighter. Anything brighter than about magnitude −1 is easy to spot even from a city.
- End time and direction. Where it sets or, often, where it vanishes into Earth’s shadow. A pass that ends high in the sky fades out over a few seconds, which is striking to watch.
Watching a pass
- Be outside a few minutes early. Face the direction where the pass starts and give your eyes a moment to adjust.
- Look for a steady light. Aircraft blink and usually carry red and green lights. The ISS shines with a steady white or slightly golden light and moves smoothly, faster than most planes appear to.
- Follow it with binoculars if you like. They won’t show its shape, but they make it look brighter. Telescopes can show the solar arrays, but tracking something this fast by hand is difficult and usually takes practice.
- Watch the end. If it fades mid-sky, you’re seeing it enter Earth’s shadow: sunset, for the crew.
No dark site is needed. Bright passes are easy from city centers, which makes the station one of the best first targets for anyone, including children. If you enjoy it, the same timing logic applies to other satellites; see how to see Starlink satellites and the satellites section.
Photographing the ISS
Put a camera or phone on something steady, frame the part of the sky the station will cross, and take a long exposure of 10 to 30 seconds, or use a night or long-exposure mode. The station records as a bright streak across the stars. Several consecutive frames can be stacked into one long trail. Close-up photos of the station’s shape need a telescope and tracking, and are an advanced project.