Earth's Satellites

A heavenly body that revolves round the earth in a circular orbit is called earth's satellite. For example, the moon is the earth's satellite which revolves round the earth in circular orbit of radius 3.84^5km. The moon takes about 27.3 days to move once round the earth.The earth's satellites are of two types: Natural satellite and Artificial satellite.

• Natural satellites:It is a naturally formed body moving around the earth.The moon is the only natural satellite of the earth.
• Artificial satellite:It is a man made body moving around the earth in an orbit.When a body is taken to a certain height above the earth and given necessary centripetal force,the body keeps on moving around the earth and becomes an artificial satellite.

Now a days, the artificial satellites find widespread application in the present world. The following are the uses of artificial satellite.

1. Artificial satellites are widely used in telecommunication.
2. They are used in studying the atmosphere near the earth surfaces.
3. They are used to forecast weather.
4. They are used to transmit radio and video signals.
5. They are used to know the shape and size of earth.
6. They are used in space flights.
7. They are used to study the radiations conform the sun and the outer space.
8. They are used to find another natural satellites which lies in our universe.