If you've ever seen a perfectly straight string of lights sliding across the night sky — dozens of points, evenly spaced, like a glowing freight train — you've seen Starlink. It's one of the most striking things visible in the modern sky, and one of the most misunderstood. It's also temporary, which is exactly why you need to know when to look.

Why the train happens

SpaceX launches Starlink satellites in batches — typically a couple dozen per Falcon 9 flight. Right after deployment, the whole batch is packed together in a low orbit, and they cross the sky as a tight, bright line. Over the following days and weeks, each satellite raises itself toward its operational orbit around 550 km, the spacing stretches out, and the satellites orient themselves to minimize reflected sunlight. The train dissolves into ordinary, faint satellites.

Translation: the show has an expiration date. The best views are one to four days after launch. A week or two later, that same batch is dim and scattered.

When and where to look

What it looks like

Fresh trains are typically magnitude 1–3 per satellite — individually modest, collectively unmistakable. You might see anywhere from a handful to dozens of points in a line, taking a few minutes to cross. It's regularly mistaken for a UFO fleet; local news gets calls after nearly every visible pass of a fresh train.

How Flyby handles it

Flyby tracks every Starlink launch and every satellite in the constellation — you can toggle the whole Starlink layer on the 3D globe and watch the shells move in real time. More usefully, its visibility engine knows which batches are fresh and bright versus old and faint, so when it tells you a train is crossing your sky tonight, it's a train you'll actually see. One notification, a direction to face, and the AR view to confirm you're looking at the right line of lights.

And if you'd rather catch the rocket that puts them up there in the first place — that's often visible too. Here's how to watch a launch from your backyard.

Tonight, look up.

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