The Kuiper belt, named after astronomer Gerard Kuiper, is a massive, icy region of our solar system that exists just beyond the planets. Actually shaped more like a donut than a flat belt, the Kuiper belt is best known as home of the dwarf planet Pluto.
Topic: Earth & Space
Why is Pluto considered a dwarf planet?
The International Astronomical Union decided that full-sized planets must orbit the sun, have a round shape, and have cleared their orbits of other objects. Pluto fulfills the first two criteria, but not the third.