# Describe various orbits for artificial satellites.

ANS:


* Artificial satellites are kept in (i)Equatorial orbit (ii)Polar orbit.
* The orbit which is parallel to the equator is known as Equatorial orbit.
* If a satellite is placed at a height of 35786 km, its revolution period is 24 hours. Such asatellite is called 'Geostationary' as it appears stationary in space when observed from earth.
* By proper arrangement of several geostationary satellites we can link all corners of the earth with one another.
* Satellites in equatorial orbits do not require energy for revolutions.
* The orbit which is parallel to the Meridian is called Polar orbit.
* If a satellite is placed at a height of about 1000 km, its revolution period is about 2 hours. Such satellites complete several revolutions around earth in a day and they pass over a location on the earth at regular time interval.
* Remote sensing satellites of India visit any location on the earth at the interval of 21 days whereas America's Landsat takes 16 days for that.
* Like natural satellites, the orbits of artificial satellites are elliptical due to gravity effect.