The Chicxulub crater is the one that killed the dinosaurs, 70% of species on Earth. It is proposed to have come from a low angle, which sent superheated dust and rock into the atmosphere. Blocking out the sun for a year.
There are 500 000 asteroids in our main asteroid belt.
The dust cloud forming the sun also caused lots of collisions which stuck together and made the solar system.
90 000 miles in diameter, is Jupiter. The mass creates a giant gravitational force pulling on most things including asteroids.
It limited the formation of other planets and the asteroid belt is where it is because of Jupiter.