Geo-stationary satellite: If an artificial satellite is placed in an orbit of the equatorial plane in such a way, that it is concentric and coplanar with the equatorial plane of the earth and the time of its revolution coincides with the revolution of the earth i.e., from west to east in 24 hours, then the satellite will appear in the same place from the earth. Such a satellite is called geo-stationary satellite. The orbit in which the satellite appears to be stationary is called parking orbit. It is an earth-orbiting satellite, placed at an altitude of approximately 35,800 kilometers directly over the equator, that revolves in the same direction the earth rotates (west to east).
If the period of revolution of a satellite is equal to the period of revolution of the earth about its own axis the satellite will remain stationary with respect to the earth. This type of satellite is called geostationary satellite.
