What would happen if the kuiper belt didn exist?
It would not have much effect on the Solar system. The Kuiper belt is mostly empty space and so far, we have not found any large bodies in it. If it was much, much, much heavier, it would tend to make Neptune’s orbit flatten out so it was closer to the average plane of the orbits of Kuiper belt objects. (Because when Neptune is above the plane it is accelerated downwards and when below the plane it would be accelerated upwards. Its orbit would precess like a top spinning down in Earth’s gravity field and its orbit would gradually flatten out.) However, that is assuming that it is many time more heavy that it is. In practical terms, the KB is so sparse & its bodies are so small that there is no effect on Neptune’s orbit. Altho it does not have much mass, the mass it does have has a large amount of angular momentum gained from the gas & dust cloud that formed the solar system. Not important for your question, but something to keep in mind. btw: the current theories say that comets come f
