Saturday, April 24, 2010

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 a circular orbit of radius 3.84*10^5km.The moon takes about 27.3 days to move once round the earth.The earth's satllite are of two types: natural satellites and artificial satellites.

Natural satelite:
It is a naturally formed body moving around the earth.The moon is the only natural satellite of earth.

Artificial satellite:
It is 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 atrificial satellite.


Nowadays, the artificial satellites find widenespread applications in the present worrld.The following are the uses of artificial satellites:
  • Artificial satellites are widely used in telecommunication.
  • They are used in studying the atmosphere near the earth surface.
  • They are used to forecast weather.
  • They are used to transmit rafio and video signals.
  • They are used to know the shape and size of the earth.
  • They are used in space flights.
  • They are used to study the radiations coming from the sun and the outer space.

1 comment:

  1. this is bad science -- don't mention centripetal and satellites in the same breath. Answer me these two questions -- why hasn't the moon come crashing down (to earth)? And ... If the sphere of planet Saturn were to stop rotating (about its axis) what would happen to its rings?

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