GUIDES
How to actually see the space stations
Everything on this site rests on one idea: a satellite is only visible when it is still in sunlight while your sky is already dark. Everything else — elevation, azimuth, magnitude, why a week goes by without a single pass — follows from that.
These guides explain the parts that the pass tables cannot: what the numbers mean, why predictions change from day to day, how to tell the station from an aircraft or a Starlink train, and how to photograph something that crosses your sky in four minutes. They are written for people who want to look up once and get it right, not for people collecting facts.
Nothing here is generated prose. The articles are written and edited by hand; the pass tables are calculated from orbital data and rebuilt every day.
Basics
BasicsBest time of year to watch the ISS
There is no single best month. The good weeks depend on the angle between the orbit and the Sun, and here is how that cycle works.
BasicsComparing the ISS and Tiangong
Two crewed stations, two orbits. Why one passes overhead where the other cannot, and how to tell which one you are watching.
BasicsFlyby or pass? What the difference actually means
Flyby and pass describe the same overhead event, but they are used in different company. Here is where each word comes from.
BasicsHow often does the ISS pass over my city?
The station circles Earth 15 times a day, yet you can go weeks without a visible pass. Here is why the schedule behaves that way.
BasicsHow to photograph the ISS
A moving point of light, a dark sky and a camera, and what it takes to turn a pass into a photograph worth keeping.
BasicsHow to read elevation and azimuth in a pass table
What the numbers in a satellite pass table mean, how to turn them into a place to stand and look, and which rows are worth your time.
BasicsHow to see the ISS tonight (without an app)
What to look for, when to look, and why an ordinary evening is often the wrong one — a plain guide to spotting the space station.
BasicsStarlink or the space station? How to tell them apart
Both look like moving dots of light, but they behave differently. Here is what separates a Starlink train from an ISS pass.
BasicsThe ISS orbit, and why 51.6 degrees decides what you can see
The station circles Earth every 92 minutes at 400 kilometres, tilted 51.6 degrees. That tilt explains almost everything about its passes.
BasicsTiangong: how to see China's space station
Tiangong is smaller and lower than the ISS, and its orbit never goes far north. Here is how to catch it from the ground.
BasicsWhy passes cluster at dusk and dawn
Visible satellite passes almost all fall in two short windows. The reason is the geometry of sunlight on a low orbit.
BasicsWhy there are no ISS passes this week
An empty pass table is normal geometry, not a fault. Here is why the station vanishes for weeks at a time, and when it comes back.
Observing
ObservingLight pollution and seeing satellites
City glow hides faint stars but not a bright pass. What light pollution actually takes away, and how to work around it.
ObservingSpace station sightings in winter
Early sunsets and long dark evenings make winter the best season for evening passes. What changes, and what to wear.
ObservingSpotting the ISS from a balcony or a small garden
No telescope, no dark sky and no big garden needed. A workable method for seeing passes from a small, obstructed space.
ObservingWhat the ISS actually looks like from the ground
Why the space station is a point of light rather than a shape, and why its brightness changes from one pass to the next.
Predictions
PredictionsHow TLE data and SGP4 predictions work
Element sets, propagation and plain geometry — how two lines of text become a time, a direction and a brightness.
PredictionsPass tables or an app — which should you use
Both use the same orbital data. The real difference is how you plan, how you find the direction, and what happens to your night vision.
How this site is maintained
Orbital elements (TLEs) are collected from CelesTrak and propagated with SGP4 every day. City pages are rebuilt from that data, so a page that says "no passes in seven days" is a measurement, not a placeholder. When a prediction turns out wrong, it is almost always because the orbit was reboosted or the elements aged — the next rebuild corrects it.
Corrections and questions: see the about page.