Free tool · Ontario Telescope
When can I see the Space Station?
The ISS orbits about 400 km up at roughly 28,000 km/h, and when the geometry is right it crosses your sky as the brightest moving point up there. No telescope required. Tell us where you are and we will tell you when to look, where it comes up, and where it goes.
01Your location
Pass times depend entirely on where you are standing — a town 100 km away sees a different pass at a different time. Everything is worked out in your browser; no location data is sent to us or stored.
Observing site
Display
Advanced
02Where it is right now
Live position, recomputed every second from the current orbital element set.
03Visible passes
Choose a location to see when the station comes over.
04Live from the station
NASA’s external camera feed. It cuts to a blue or black screen during signal handovers between relay satellites and when the crew is off duty — that is normal, it comes back on its own.
Player not loading, or the stream has moved? Open NASA’s live streams on YouTube.
05How this works
Short version: the station has to be in sunlight while you are in the dark.
Why you can only see it near dawn and dusk
The ISS produces no light of its own. What you see is sunlight bouncing off 2,500 square metres of solar array. So a pass is visible only when three things line up at once:
At 400 km altitude the station stays lit for a while after your local sunset, because it is high enough to still catch the sun. That window is roughly the two hours after dusk and the two hours before dawn. In the middle of the night the station is usually flying through Earth’s shadow, and in daylight it is there but lost in the glare.
This is also why passes come in clusters. Visibility follows the angle between the station’s orbit plane and the sun, which drifts on a cycle of about six weeks. You will get a run of good evenings, then a couple of weeks with nothing, then another run.
Reading the numbers
- Appears / Disappears — the compass direction and how high above the horizon, in degrees. Your fist held at arm’s length is about 10°.
- Highest point — the peak of the arc. Anything above 45° is a good pass; above 70° is close to straight overhead and will be genuinely bright.
- Magnitude — astronomical brightness, where lower is brighter. Vega is 0.0, Sirius is −1.5. A good ISS pass reaches about −3.5, which outshines everything in the sky except the moon and occasionally Venus.
- Ends by entering shadow — instead of setting, the station flies into Earth’s shadow and fades out mid-sky over a few seconds. It is one of the better things to watch for.
How to actually catch it
Be outside five minutes early and face the direction listed under Appears. Look for a bright, steady white point moving smoothly and silently — aircraft blink, the station does not. It crosses the whole sky in three to six minutes, so once it starts there is no time to go back inside for anything.
What you need
Nothing. It is a naked-eye object and always will be. That said, a pair of wide-field binoculars turns a moving dot into an object with a shape, and on a high pass through a fast, manually-swept Dobsonian you can occasionally make out the solar arrays. Tracking mounts are the wrong tool here — the station moves far too quickly for most of them.
Binoculars
Wide field, easy to sweep, and useful for everything else in the sky. The single best first purchase for a new observer.
Browse binocularsTelescopes
Once the station has your attention, the moon, Saturn and Jupiter are the natural next step.
Browse telescopesMore free tools
Focus stepping, flat frames, guide scope matching and double-star resolving calculators.
Free utilitiesHow the prediction is made
The page fetches the station’s current orbital element set — the same two-line format published by NORAD — and runs the standard SGP4 propagator in your browser to work out where the station is, second by second, for the period you asked for. It then computes your local horizon geometry, the sun’s position, and whether the station is inside Earth’s umbra, and reports every window where all three visibility conditions hold.
Nothing runs on our server and no account or API key is involved. The trade-off is accuracy over time: element sets age. Inside a week the times here are good to well under a minute. A month out they drift, because the station raises its orbit periodically and atmospheric drag is not perfectly predictable. Check back closer to the date for anything more than a week away.
06Questions
Why does it say there are no visible passes this week?
That is normal and it happens to everyone a few times a year. The station’s orbit plane drifts relative to the sun on a roughly six-week cycle, and for part of that cycle every pass over your location happens in daylight or with the station in Earth’s shadow. Switch to the month view and you will usually see the next run of evenings appear.
How accurate are the times?
Within a week, typically better than a minute, which is well inside the margin you need for naked-eye observing. Further out the prediction degrades, because the station performs reboost manoeuvres and because atmospheric drag varies with solar activity. The footer of this page shows the age of the element set the calculation is based on.
Is that really the station, or am I looking at a plane?
Aircraft have blinking navigation lights and usually a red or green tint; the station is a steady white point with no flashing at all. It also moves at a very distinctive pace — noticeably faster than a high-altitude aircraft, slower than a meteor, and in a perfectly straight line. If it fades out in the middle of the sky rather than setting, that is the station entering Earth’s shadow, and nothing else does that.
Can I see the astronauts, or the solar panels?
Not the crew. On a high pass through binoculars the station is clearly not a point of light, and through a telescope swept by hand you can sometimes resolve the main truss and the arrays as a bright rectangle. It takes practice, because at closest approach the station is crossing the sky at over a degree per second.
What about Starlink trains and other satellites?
The same maths works for any satellite with a published element set. This page is set up for the ISS because it is by far the brightest and the easiest to plan around. If a satellite tracker for other objects would be useful to you, tell us — we build these tools based on what customers ask for.