Question

What keeps planets,comets and asteroids revolving around the sun in their orbit?

Answer 1

centripetal force means force exerted from centre and here this force Is exerted by sun which helps planets to revolve around it.

Answer 2

The planets are formed from the spinning-disc shaped cloud and continued this rotating courses around the sun after they were formed. The gravity of the sun keeps the planets in in their orbit. They stay in their orbit because there is no other force in the solar system which can stop them.