how are the above mentioned belts formed?
A hypothesis to the asteroid belt creation is that in general, in the Solar System, a planetary formation is thought to have occurred via a process comparable to the long-standing nebular hypothesis: a cloud of interstellar dust and gas collapsed under the influence of gravity to form a rotating disc of material that then further condensed to form the Sun and planets.
Asteroid belt
A hypothesis to the asteroid belt creation is that in general, in the Solar System, a planetary formation is thought to have occurred via a process comparable to the long-standing nebular hypothesis: a cloud of interstellar dust and gas collapsed under the influence of gravity to form a rotating disc of material that then further condensed to form the Sun and planets. 
where are most asteroids located in our solar system Asteroid belt which is located roughly between the orbits of the planets Jupiter and Mars what is this belt? It is a torus-shaped region in the Solar System what is this system mentioned above? The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly
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Asteroid belt [SEP] Formation
In 2018, a study from researchers at the University of Florida found the asteroid belt was created from the remnants of several ancient planets instead of a single planet. A hypothesis to the asteroid belt creation is that in general, in the Solar System, a planetary formation is thought to have occurred via a process comparable to the long-standing nebular hypothesis: a cloud of interstellar dust and gas collapsed under the influence of gravity to form a rotating disc of material that then further condensed to form the Sun and planets. During the first few million years of the Solar System's history, an accretion process of sticky collisions caused the clumping of small particles, which gradually increased in size.