It's one of the most common "Did you see that?!" moments in the sky today: a neat line of bright dots, evenly spaced, gliding silently across the darkness in single file. It looks otherworldly — but it isn't a UFO. It's a Starlink satellite train, and once you know what you're seeing, it becomes one of the coolest things to catch overhead.
What Starlink is
Starlink is SpaceX's satellite-internet network — a "constellation" of satellites in low Earth orbit (around 550 km up) that beams broadband internet to the ground, including to remote places that cable and cell towers never reached. It's by far the largest satellite constellation ever built: more than 10,000 satellites are already in orbit, launched in batches of roughly 20 or more at a time, with new ones going up almost weekly.
Why they look like a string of pearls
The "train" effect is a temporary phase of each launch. When a fresh batch is released, the satellites travel clustered tightly together in a line before they gradually spread out and climb to their final, higher orbits. In those first days they're low, close together, and easy to see catching the sun — so they appear as that unmistakable string of evenly spaced lights. Within a week or two they disperse across the sky and blend in with everything else.
Catching a Starlink train
- When: in the day or two after a launch, during the dawn or dusk viewing window.
- What: a line of evenly spaced, steady (non-blinking) dots moving together.
- Where: depends on the orbit and your location — timing is everything.
- Heads up: the train fades over the following days as the satellites spread out.
How to know when a train is overhead
Because the window is short, catching a train is all about timing. A tracker that follows recent launches can predict when a fresh Starlink train will cross your sky and from which direction — turning a lucky sighting into something you can plan around and show the kids.
Love them or loathe them
Starlink is genuinely transformative — bringing fast internet to rural homes, ships, planes and disaster zones. It's also controversial: astronomers have raised real concerns about thousands of bright satellites streaking through telescope images and altering the natural night sky. Both things are true at once, which is part of why the trains are so fascinating to watch: you're seeing one of the biggest changes to the night sky in human history, live, from your backyard.
Quick answers
How many Starlink satellites are there? More than 10,000 are already in orbit, and the number keeps climbing as SpaceX launches new batches almost every week.
Why does the train disappear after a few days? The satellites launch in a tight cluster, then gradually spread out and raise themselves to higher orbits. Within a week or two they're dispersed across the sky and no longer form a visible line.
How high are they? Starlink satellites orbit in low Earth orbit, around 550 km (about 340 miles) up — much lower than most communications satellites.
Are they bad for stargazing? Astronomers have real concerns about bright satellites streaking through telescope images, and SpaceX has added darkening measures to reduce their glare. It's an ongoing debate.
Is it really internet? Yes — the constellation delivers broadband to homes, ships, planes and remote regions that traditional cable and cell networks never reached.
