A geostationary orbit is one where a satellite's orbital period exactly matches the planet's rotation, so it appears to hover motionless over a single point on the surface — essential for communication and weather satellites.
A geostationary orbit is one where a satellite's orbital period exactly matches the planet's rotation, so it appears to hover motionless over a single point on the surface — essential for communication and weather satellites. This calculator finds the orbital radius and altitude required.
For Earth (M = 5.97×10²⁴ kg, T = 86,164 s, R = 6.371×10⁶ m): Orbital Radius ≈ 4.216×10⁷ m, so Altitude ≈ 3.579×10⁷ m (about 35,786 km) — matching the real altitude of geostationary satellites.
It's an orbit where a satellite matches Earth's rotation, appearing to stay fixed above the same point on the equator at all times.
It's derived by setting the satellite's orbital period equal to Earth's rotational period (about 23 hours 56 minutes) and solving Kepler's third law for the corresponding orbital radius, giving an altitude of about 35,786 km.
Because they stay fixed relative to a point on Earth, ground antennas don't need to track their movement, and they provide continuous coverage of the same region.