A geosynchronous orbit is an orbit around a planet or moon with an orbital period that matches the planet or moon's sidereal rotation period. The term most frequently refers to objects that orbit the Earth, and this article reflects that. The synchronization of rotation and orbital period means that for an observer at a fixed location on the surface, a satellite in geosynchronous orbit returns to exactly the same place in the sky at exactly the s...
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A geosynchronous orbit is an orbit around a planet or moon with an orbital period that matches the planet or moon's sidereal rotation period. The term most frequently refers to objects that orbit the Earth, and this article reflects that. The synchronization of rotation and orbital period means that for an observer at a fixed location on the surface, a satellite in geosynchronous orbit returns to exactly the same place in the sky at exactly the same time each day. In principle, any orbit with a period equal to the Earth's rotational period is technically geosynchronous; however, the term is often used to refer to the special case of a geosynchronous orbit that is circular (or nearly circular) and at zero (or nearly zero) inclination, that is, directly above the equator. This is customarily called a geostationary orbit.
A semisynchronous orbit has an orbital period of 0.5 sidereal days, i.e. 11 h 58 min. Relative to the Earth's surface it has twice this period, and hence appears to go...
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