ISS passes over your city
The International Space Station looks like a bright, steady star gliding across the sky in a few minutes, with no blinking lights. It can only be seen around dawn and dusk, when your sky is dark but the station, 250 miles up, is still in sunlight. Enter your city or ZIP code for every visible pass in the next 10 days.
Passes
Choose a location to see the passes.
How to see the ISS
Be outside a couple of minutes early and face the direction the pass starts from. The station rises low in the sky, climbs to its highest point and then sinks or simply fades out as it enters Earth's shadow. A pass that reaches 40° or more is high and easy; low passes are often lost behind trees and buildings. No binoculars are needed, and it is bright enough to see from the middle of a city.
Visible passes come in runs. For a week or two you may see it every evening or every morning, then not at all for a while, because the station's orbit drifts relative to sunrise and sunset. Our guide to seeing the ISS explains more, and your city's tonight page includes tonight's passes in the score.
How these passes are calculated
We download the station's current orbital elements from CelesTrak (at most twice a day per visitor) and work out its position every 20 seconds with the standard SGP4 orbit model. A pass is listed when the station is at least 10° above your horizon, lit by the Sun, while the Sun is at least 6° below your horizon. NASA's Spot the Station app uses similar rules but counts passes from 5° up; we start at 10° because lower passes are usually hidden by trees and buildings. Brightness is estimated from the station's distance; lower numbers are brighter, and the brightest stars are around magnitude 0. Our times agree with other pass predictors to within about a minute.