A geostationary satellite appears to hang motionless over a single point on the equator. It isn't stationary — it's moving at 3.07 km/s. But its orbital period exactly matches Earth's rotation, so from the ground it never appears to move.
A geostationary satellite appears to hang motionless over a single point on the equator. It isn't stationary — it's moving at 3.07 km/s. But its orbital period exactly matches Earth's rotation, so from the ground it never appears to move.
Geostationary orbit (GEO) exists at exactly 35,786 km above the equator. This is the one altitude where the orbital period equals 23 hours, 56 minutes and 4 seconds — one sidereal day.
From Earth's surface, a GEO satellite appears fixed in the sky. This is why your satellite TV dish points at one spot and never needs to move — the satellite isn't going anywhere relative to you.
The ability to 'park' a satellite over a fixed point has enormous practical value — but the slots are limited and hotly contested.
These terms are often confused. They're related but not identical.
GEO satellites are stationary in space
They're moving at 3.07 km/s — faster than a bullet. They appear stationary because they match Earth's rotation exactly.
You can put a GEO satellite over London
GEO only works over the equator (0° latitude). Satellites 'serving' London are positioned over the equator at a longitude with good coverage angle to the UK.
One altitude. One inclination. 180 usable slots. Geostationary orbit is the most commercially valuable region in space — and understanding why it works is the capstone of orbital basics.