- Synchronous orbit
A synchronous orbit is an
orbit in which an orbiting body (usually asatellite ) has a period equal to the average rotational period of the body being orbited (usually a planet), and in the same direction of rotation as that body.Properties
A satellite in a synchronous orbit that is both equatorial and circular will appear to be suspended motionless above a point on the orbited planet's equator. However, a synchronous orbit need not be equatorial; nor circular. A body in a non-equatorial synchronous orbit will appear to oscillate north and south above a point on the planet's equator, while a body in an elliptical orbit will appear to oscillate eastward and westward. As seen from the orbited body the combination of these two motions produces a figure-8 pattern called an
analemma .Nomenclature
Like many orbital terms synchronous orbits take on special names depending on the body being orbited. The following are some of the more common names. A synchronous orbit about the
Earth that is circular and lies in the equatorial plane is called ageostationary orbit . The more general case, when the orbit is inclined to the Earth's equator or is non-circular is called ageosynchronous orbit . The corresponding terms for synchronous orbits around the planetMars are areostationary and areosynchronous orbits.Examples
An astronomical example is
Pluto 's moon Charon. Much more commonly synchronous orbits are employed by artificial satellites used for communication, such asgeostationary satellites .For natural satellites, which can attain a synchronous orbit only by tidally locking their parent body, it always goes in hand with
synchronous rotation of the satellite. This is because the smaller body becomes tidally locked faster, and by the time a synchronous orbit is achieved, it has had a locked synchronous rotation for a long time already.ee also
*
Subsynchronous orbit
* Supersynchronous or Graveyard orbit
*Synchronous rotation
*Sun-synchronous orbit
*List of orbits References
*
Federal Standard 1037C
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