🛰 When to See the ISS

…or start from a city: Kuala LumpurJakartaSingaporeBangkokLondonNew YorkTokyoSydneyDubaiMumbaiCairoLagosSão PauloReykjavík

Why the ISS is visible at all

The Station has no lights worth speaking of — it shines because the Sun hits it, and it is only worth watching in the hour or two after your sunset or before your sunrise, when you stand in Earth's shadow but the station, 400 km up, still catches direct sunlight. High enough above the horizon, it outshines every planet and moves from horizon to horizon in about five minutes with no sound and no blinking — a steady bright train, easily mistaken for an aircraft until you notice it never deviates and is far faster.

How to use a pass prediction

Pick a pass with the largest max elevation and mark naked-eye: go outside two minutes before the start time, face the entering compass point (14 example cities above), and watch the sky, not the horizon — trees and buildings hide low passes. At the peak moment it is highest in the south (if you are in the northern hemisphere) or in the north (if you are in the southern). If the sky is overcast, the next one is usually the same evening, a few minutes earlier.

Predictions come from the station's live orbital elements (updated a few times a week as it is reboosted and dragged) propagated with the same SGP4 mathematics the professionals use — computed on our own server, not bought from anyone. For where it is this second, see ISS Live; for its hardware and the whole tracked fleet, see Satellites.