geostationary orbit (Clarke orbit) A satellite orbit in which the satellite travels on the equatorial plane in the same direction as the rotation of the Earth at a height of about 36 000 km (more than 5 Earth radii) above the equator. Its orbital period is exactly one sidereal day and therefore the satellite remains vertically above a fixed spot on the surface of the Earth. At this height it has a view of almost the whole of one hemisphere. The possibility of such an orbit was first suggested by Arthur C. Clarke, for whom the orbit is sometimes named. Compare GEOSYNCHRONOUS ORBIT.

geostationary orbit Location of an artificial satellite so that it remains above the same point on a planet's surface because it completes one orbit in the same time it takes that planet to rotate once on its axis. Communications and remote-sensing satellites are often placed in geostationary orbits.