Geosynchronous orbit

A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered <a href="/facts/Orbit/nD2TPySG">orbit</a> with an <a href="/facts/Orbital_period/94f56uh2">orbital period</a> that matches <a href="/facts/Earth%2527s_rotation/mDbXcKUx">Earth's rotation</a> on its axis, 23 hours, 56 minutes, and 4 seconds (one <a href="/facts/Sidereal_day/2JAVf8dy">sidereal day</a>). The synchronization of rotation and orbital period means that, for an observer on Earth's surface, an object in geosynchronous orbit returns to exactly the same position in the sky after a period of one sidereal day. Over the course of a day, the object's position in the sky may remain still or trace out a path, <a href="/facts/Analemma/BSdqWqfs">typically in a figure-8 form</a>, whose precise characteristics depend on the orbit's <a href="/facts/Orbital_inclination/TQCFWyfd">inclination</a> and <a href="/facts/Orbital_eccentricity/WGlB4NBn">eccentricity</a>. A circular geosynchronous orbit has a constant altitude of 35,786 km (22,236 mi).
A special case of geosynchronous orbit is the <a href="/facts/Geostationary_orbit/VBq1v5Kr">geostationary orbit</a> (often abbreviated GEO), which is a circular geosynchronous orbit in Earth's <a href="/facts/Equatorial_plane/P9Lyq2DE">equatorial plane</a> with both inclination and eccentricity equal to 0. A satellite in a geostationary orbit remains in the same position in the sky to observers on the surface.
<a href="/facts/Communications_satellite/y5RXPMDT">Communications satellites</a> are often given geostationary or close-to-geostationary orbits, so that the <a href="/facts/Satellite_antenna/4MgSzKnC">satellite antennas</a> that communicate with them do not have to move but can be pointed permanently at the fixed location in the sky where the satellite appears.

Geosynchronous orbit open-in-new

Geosynchronous orbit