What is asteroids

What are asteroids.

Asteroids are the rock pieces that revolve around the sun between the orbits of Mars and Jupiter. There are nearby one lakh asteroids. The largest asteroid called Ceres has a radius of 350 km while the smallest is about 6 m across in size. 

Asteroids are believed to be the pieces of a much larger planet which might have broken up due to the gravitational effect of Jupiter.