📘 Definition
Geostationary Earth Orbit (GEO) is a circular orbit at exactly 35,786 km altitude above the equator, where the orbital period matches Earth's rotation (23 hours 56 minutes). A satellite in GEO appears stationary relative to a point on the ground, making it ideal for telecommunications, television broadcasting, and weather monitoring. GEO slots are a finite, internationally regulated resource coordinated by the ITU. At end of life, GEO satellites are moved to a graveyard orbit approximately 300 km above GEO.
35,786 km
Altitude
23h 56m (sidereal day)
Orbital Period
0° (equatorial)
Inclination
1,484
Objects Tracked
Understanding GEO
Why "Stationary"?
At 35,786 km, a satellite's orbital period exactly matches Earth's rotation. From the ground, it appears fixed in the sky — ideal for dish antennas that can be permanently pointed at one spot. Arthur C. Clarke proposed this concept in 1945, which is why GEO is sometimes called the Clarke orbit.
GEO Slot Regulation
Because GEO satellites must maintain their longitude, orbital positions (called "slots") are finite and internationally regulated by the ITU. Prime slots over populated regions are extremely valuable and have been a source of geopolitical competition.