Sky Arc

A sky arc (or pass arc) is the apparent curved path a satellite follows across the dome of the sky during a single visible pass. It begins where the satellite rises above the horizon, climbs to its highest point — the peak elevation — and ends where it sets on the opposite side. Pass-prediction tools render the arc on a sky-dome chart, plotting elevation and azimuth over time so an observer knows exactly where to look and how the pass will unfold. The height and shape of the arc determine how bright and long the pass is: a high, overhead arc is far better than a low one skimming the horizon.