There are about 15,000 satellites orbiting the Earth. Most of them, like the International Space Station and the Hubble Telescope, reside in low Earth orbit, or LEO, which tops out at about 1,200 miles (2,000 kilometers) above the Earth’s surface.
But as more and more satellites are launched into LEO – SpaceX’s Starlink internet constellation alone will eventually send many thousands more there – the region’s getting a bit crowded.
