How to see the ISS and other satellites
You don't need a telescope, an app or any experience. On a clear evening, step outside at the right minute, look in the right direction, and a bright point of light will glide across the sky. Here's how to make sure you catch it.
When to look
Satellites shine by reflecting sunlight. You can see one when it is still lit by the sun high above you while your own sky has gone dark, which means in the hours after sunset and before sunrise. Most nights bring a handful of passes, and the brightest ones are worth planning for. Satellite Hunters lists every visible pass for your location, with the cloud forecast for each one.
Where to look
Each pass comes with a compass direction where it appears, how high it climbs, and where it leaves. Height is given in degrees: 0° is the horizon and 90° is straight overhead. A fist held at arm's length covers about 10° of sky, so a pass that peaks at 40° is four fists up. Get outside a couple of minutes early, face the starting direction and look a little above the horizon.
What you'll see
A steady point of light, often brighter than the brightest stars, moving smoothly and silently. A pass lasts from one to about six minutes. Many end before the satellite reaches the horizon: it simply fades away in mid-sky as it enters Earth's shadow.
Give your eyes time
Your eyes take around twenty minutes to adjust fully to the dark, and one glance at a bright screen undoes it. Turn on red-light mode on Satellite Hunters before you go out; red light disturbs night vision far less than white.
What to hunt
- The International Space Station. The brightest and easiest. It orbits about 400 km up, circles the Earth roughly every 90 minutes, and on a good pass outshines every star.
- Tiangong, the Chinese space station. Smaller and fainter than the ISS, and its orbit keeps it low in the southern sky or below the horizon from most of the Nordic countries.
- Rocket bodies and old satellites. Spent rocket stages and retired satellites are among the brightest objects up there. Some tumble and flicker as they turn.
Satellite Hunters follows about 150 of the brightest objects in orbit. Logging each one you catch earns a rank in the society, and members are listed on the roll.
Frequently asked questions
What time can I see the ISS tonight?
It depends on where you are, and on many nights there is no visible pass at all. When there is one, it usually comes within a couple of hours after sunset or before sunrise. The front page works out the exact times for your location, and there are ready-made pages for Nordic cities such as Oslo, Bergen, Stavanger and Stockholm.
Why can I only see satellites around dusk and dawn?
Satellites give off no light of their own; they shine by reflecting sunlight. You see one when the satellite is still in sunshine high above you while your own sky has gone dark. That happens in the hours after sunset and before sunrise. In the middle of the night most satellites are in Earth's shadow, and in daytime the sky is too bright.
Do I need a telescope or binoculars?
No. The International Space Station and the other satellites listed on Satellite Hunters are visible with the naked eye. Binoculars are a nice extra for finding fainter ones, but a telescope is more hindrance than help, because satellites move too fast to follow.
How can I tell a satellite from a plane?
A satellite is a steady point of light gliding smoothly across the sky in silence. Planes have flashing red, green or white lights and often make noise. A satellite never blinks, although some tumbling rocket bodies flicker as they turn.
Why did the satellite disappear in the middle of the sky?
It flew into Earth's shadow. The sunlight reflecting off it is cut off, so it fades out within a few seconds even though it is still well above the horizon. Satellite Hunters marks these passes with "fades in shadow".
Why are there no ISS passes for days at a time?
Visible ISS passes come in spells of a week or two. Between them, the space station crosses your sky in daylight or in the middle of the night, when it is in Earth's shadow. The pattern shifts as its orbit slowly turns, so the passes always come back.
Can I see the Hubble Space Telescope from Norway?
No. Hubble's orbit is tilted only 28.5 degrees from the equator, so from the Nordic countries it never rises above the horizon. You need to be south of about 50 degrees north to have any chance.
Can I see satellites in summer in the Nordic countries?
In southern Norway, Sweden and Finland, yes: around midsummer the sun stays just below the horizon, satellites stay sunlit all night, and passes can come at any hour, though the pale sky hides the fainter ones. North of the Arctic Circle the midnight sun keeps the sky too bright, so there are no visible passes for weeks around midsummer.
How accurate are the times?
Usually to within a minute. Satellite Hunters uses the latest orbital elements from CelesTrak, refreshed several times a day. The ISS occasionally fires its engines to raise its orbit, which can shift predictions made a few days ahead, so check again on the day.