Question:What is responsible for the asteroid belt between Mars and Jupiter?
The gravitational attraction of Jupiter.
Asteroids joining together at the start of the Solar system produced the planets we have today.
The asteroids that formed the planets were pulled towards each other by their own gravity.
This did not happen to the asteroids between Mars and Jupiter; which is strange and makes us wonder what was different at this location.
The answer is that Jupiter is so large that its gravitational attraction is very strong - much stronger that any of the other planets; it is so strong that it has prevented the formation of another planet between Mars and Jupiter by disrupting the much smaller forces between the asteroids trying to pull themselves together to form another planet.