Sometimes when you get a lot of facts thrown at you, it is difficult to make sense of them all at the same time. That’s when a diagram comes in handy – you just sit down and add a bit at a time. This is exactly what I did in trying to make out the structure of the Kuiper Belt. And here is the result:
With those unknowns of what happened to all objects that should be there, it’s no wonder some of the descriptions ended up being confusing. What I have not included on here are other resonances with Neptune that have fewer objects than the ones shown in the diagram, but there is nevertheless a higher concentration of objects.
But this is only the Kuiper Belt. There’s also the Scattered Disc Objects (SDO). These objects approach the Sun as close as 30 to 35 AU (Astronomical Units), but usually have highly eccentric orbits that can extend beyond 100 AU. They can also have orbital inclinations up to 40 degrees. They are thought to be the result of gravitational scattering by the gas giants (Jupiter, Saturn, Uranus and Neptune). So there is some overlap between the Kuiper Belt and SDO. A good example of an overlap object is Eris.
There are objects that are further out than either of these two sets, e.g. Sednoids, but apart from not fitting onto the diagram, little is known about them.
Does this help my science fiction? You bet it does! So I would certainly suggest using a diagram to get your thoughts straight when you have too many facts.