The ISS is the brightest satellite, but it is far from the only one. On a clear evening from a reasonably dark spot you can often catch several satellites crossing the sky, and every so often something stranger: a straight…
The ISS is the brightest satellite, but it is far from the only one. On a clear evening from a reasonably dark spot you can often catch several satellites crossing the sky, and every so often something stranger: a straight line of lights moving together. This lesson covers which satellites you can see, what a Starlink train is, and how to catch one.
Several hundred satellites are bright enough to see without any equipment. They follow the same rule as the ISS: your sky must be dark while the satellite is still sunlit.
Starlink satellites are launched in batches of 20 to 60 at a time. Just after launch they fly close together in a low orbit, one behind the other, and catch the sunlight as a string of evenly spaced dots.
Launches happen several times a month, so new trains come along often. The catch is that a train is only bright for a short time, and it has to pass over you in twilight while it is still bunched up.
Seeing a train is mostly about timing. Use a train finder or pass predictions, then follow these steps.
A straight line of lights crossing the sky must be a UFO.
It is almost certainly a recently launched batch of Starlink satellites, still flying close together before they spread out.
You can still see the famous Iridium flares.
The old Iridium satellites that made those predictable bright flares have all been taken out of orbit. Brief flashes today are glints from other satellites or tumbling debris.
You now know which satellites you can see, why Starlink trains appear and fade, and how to time a sighting. The Starlink page shows the next visible train over your location, with the time, direction and brightness.