How to See a Starlink Train
A tight line of evenly spaced lights crossing the sky is a freshly launched Starlink batch -- and the window to catch one looking like that is measured in days, not weeks.
What is a Starlink train?
If you've ever seen a string of evenly spaced lights cross the sky in a perfectly straight line, one after another like beads on a string, you weren't looking at a formation flight or a UFO sighting -- you were looking at a freshly deployed batch of Starlink satellites, still flying close together in the same orbital plane they were dropped into. A single launch deploys dozens of satellites from the same upper stage at essentially the same place and time, so they start out sharing almost exactly the same orbital tilt and orientation. That shared starting point is what makes them look like a train instead of a scatter of unrelated passes.
How do I know if one is coming?
The reliable signal is a recent Starlink launch -- trains are a "just happened" phenomenon, not a standing feature of the constellation. SpacePings' own detection logic treats a cluster as a train only when at least 5 satellites sit within 0.2 degrees of inclination and 2.0 degrees of orbital-plane orientation (RAAN) of each other -- tight enough that it's genuinely one batch, not five unrelated satellites briefly lining up by coincidence. They're also moving noticeably faster across the sky than most satellites, because a freshly deployed batch sits at an unusually low "insertion altitude" -- low enough to complete more than 15.7 orbits a day, meaningfully faster than something like the ISS at roughly 15.5.
How long will it look like a train?
Days, not weeks. That low insertion altitude isn't where Starlink satellites are meant to operate long-term -- each one raises itself under its own propulsion in the days following launch. As they climb, different altitudes mean different orbital periods, and different periods mean the once-tight formation drifts apart. The visually striking, taut, evenly spaced line is a short-lived phenomenon: genuinely there for a few days after a launch, then gone, as the satellites disperse into the general constellation and become ordinary, indistinguishable Starlink passes. The full breakdown of the mechanics is here.
How bright will it be?
Satellite brightness gets published as a "standard magnitude" -- how bright an object would appear at a fixed reference distance and lighting angle. For a Starlink v2 mini, the current and most common generation in orbit, that reference number is 5.9, on its own close to the edge of what an unaided eye can pick out under a good dark sky. A fresh train usually beats that reference number in practice, though, because the satellites are closer and often more favorably lit than the standard-angle convention assumes -- which is part of why a fresh train often reads as strikingly, unmistakably bright even though the on-paper number undersells it. Like every other pass, a train still has to clear the same darkness and elevation gates any satellite does to be worth going outside for.
The same engine that watches for ordinary bright passes and the Fade also watches the catalog for freshly launched, still-clustered Starlink batches like this -- one push, only when it's genuinely a train worth seeing, not a generic "Starlink is up there somewhere" alert. Free on iOS -- no account needed to check tonight's sky.