Geostationary Satellites

For a satellite to appear stationary relative to Earth's surface, it needs specific orbital conditions. 1. Orbit must be **circular. 2. Orbit must lie in the equatorial plane. 3. Satellite must move in the same direction as Earth’s rotation**. 4. Orbital period must equal Earth’s rotational period relative to the relevant reference, approximately one day.

Because it stays above approximately the same region of Earth, geostationary satellites are useful for: communications; broadcasting; * continuous weather observation.

Every geostationary satellite is geosynchronous, but not every geosynchronous satellite is geostationary.

For orbital period `T`: **r³ = GMT²/(4π²)**