|Satellite in Orbit.|
From Earth, a satellite in geosynchronous orbit appears to "hover" over one spot on the Equator. This helps the receiving dish on the ground. It can get information from the satellite by pointing at just one point in the sky. It doesn't have to move, or "track," the satellite across the sky.
The satellite isn't motionless, though. It's in a very high orbit and circles the Earth once a day. This orbit makes the satellite travel at the same rate as the Earth's spin.There are many satellites currently in geosynchronous orbits. The weather satellite pictures (GIF, 60k) we see on the news come from these satellites. They constantly send pictures and information to receiving dishes on Earth. The GOES weather satellites are an example of this type of satellite. (Visit the GOES Weather Imagery Site). Most cable TV channel signals are also sent around the world with these types of satellites. NASA also uses geosynchronous satellites to send communications and data back and forth between spacecraft, such as the Space Shuttle and the Hubble Space Telescope, and control centers on Earth.