(i) A man-made object which revolves around the Earth in a definite orbit is a satellite of the earth.
(ii) Sputnik was the first artificial satellite launched in 1957.
(iii) Today, there are more than thousand artificial satellites revolving around the earth.
(iv) These satellites use solar energy for their functioning and they are used for various purposes.
(v) Satellites are used for various purposes, like weather satellite, communication satellite, broadcast satellite, etc used for various operation.
(vi) Aryabhatta was the first Indian satellite.