1. Write an explanatory note on Solar System with a diagram.

ANS:


* Our solar system consists of the Sun, nine planets revolving around it, 91 satellites revolving around the planets, more than 1 lakh asteroids, comets, etc.
* It is believed that the universe was formed due to Big Bang. After the big bang the sun was surrounded by a cloud of gases. These clouds were slowly converted into rocks due to contraction. These rocks kept on colliding with one another and during this process they either got broken or fused together to form bigger structures which we call planets. Thus, the present solar system came into existence.
* The gravitational force of sun provides the centripetal force required to keep the planets in their orbits.
* About 99% mass of the solar system comes is contained in sun. Sun is the main source of energy for planets. The amount of energy of sun reaching the earth is in desired proportion, essential for the origin and sustenance of life on earth.