How to see a Starlink train
A line of bright dots crossing the sky in single file is a Starlink train, a batch of satellites a few days after launch. Here is what it is, when it can be seen and how to catch one.
Updated
A row of evenly spaced lights, moving together across the sky in a straight line, is one of the strangest things you can see with your own eyes. It is not a formation of aircraft. It is a Starlink train: a batch of new internet satellites, still flying close together a few days after their launch.
What you are looking at
Starlink satellites are launched a couple of dozen at a time. The rocket releases the whole batch into a low orbit, and over the following weeks each satellite uses its own thruster to climb to its working height of roughly 550 km.
Just after release they are close together and low, so they are bright and they follow one another along the same path, like a string of pearls. As they climb they spread apart and turn to an orientation that reflects less sunlight toward the ground. Within a few weeks the train has dissolved into separate satellites, most of them too faint to notice without knowing exactly where to look.
So a train is always fresh. If you see one, there was a launch within the last several days.
When a train is visible
The rules are the same as for seeing the space station:
- The satellites are above your horizon.
- Your sky is dark.
- The satellites, hundreds of kilometres up, are still in sunlight.
That happens in the hour or two after dusk and before dawn. A train passing over at midnight is in Earth's shadow and invisible.
Timing matters more than for any other satellite. In the first days after launch the train is at its brightest and tightest; a week later it is already much longer and fainter.
How to catch one
- Watch for a launch. Starlink launches are frequent, and each one produces a train for the following days.
- Look as early as you can after the launch, on the first evening or morning when the train passes over you in a dark sky.
- Expect the timing to be less exact than for the space station. A new batch is still changing its orbit, so a prediction made a day earlier can be off. Be outside several minutes early and keep watching.
- Face the right way. Like every satellite pass, a train rises in one direction and crosses to another. Know where it starts.
- Use your eyes, not a telescope. The train can stretch across a wide piece of sky.
Why they sometimes fade one by one
If the lights at the front of the line go out in turn while the rest are still shining, the train is entering Earth's shadow. Each satellite reaches the edge of the shadow a moment after the one ahead of it.
Starlink on this site and in the app
The globe on the live flyover map shows every tracked Starlink satellite as a green dot, at its real position this second. It is the quickest way to see how many there are, and how they are arranged in shells around the planet.
Star & Planet Finder predicts Starlink passes over your location, alongside the space station's, and can send a reminder before one rises.
