satellites

GPS was not one person's invention. It came from satellites, atomic clocks, relativity, military navigation, and decades of engineering.

There are over 8,000 active satellites orbiting Earth right now. Here's how they stay up and what they do.

Your phone's navigation relies on corrections from both special and general relativity. Without Einstein, GPS would be off by kilometers within hours.

Over 27,000 tracked debris objects threaten every satellite in Earth orbit. AI is becoming humanity's best defense against a cascade of collisions that could seal off space.

GPS uses clocks accurate to a billionth of a second and Einstein's relativity to pinpoint you anywhere on Earth within meters.

The United States leads every satellite count, largely because of Starlink: 11,114 of the 16,988 active satellites tallied on October 12, 2026. Here is how the major counts differ, who is next, and what the rankings leave out.