Filters
Point your phone at the sky
The camera shows the sky and the app draws each satellite and its predicted path on top. Video stays on your phone and is never uploaded.
If satellite paths look too long or too short against the sky, change this until they fit.
Location
Satellite data
Paste elements instead
If the download is blocked, open this address, copy everything on the page and paste it here.
Brightness
Estimated brightness of an Iridium at 1000 km range and half illumination (ISS and Tiangong use their own built-in estimates). Lower numbers make every pass brighter. Watch a few passes, compare with the estimate and nudge this until they agree. The estimate treats the satellite as a plain sphere, so expect it to be off by a magnitude or two.
Compass
About
Orbits come from CelesTrak's Iridium NEXT and space-station element sets and are computed on your phone with SGP4. The first-generation Iridium satellites that produced bright flares are gone, so Iridium passes are ordinary faint points of light. The ISS and Tiangong are much brighter, and their magnitudes here are rough estimates. Predictions drift as the elements age; refresh them every few days.