section_path: Trans-Neptunian region/Kuiper belt
section_name: Kuiper belt
paragraph_text: Kuiper belt
  
  The Kuiper belt is a great ring of debris similar to the asteroid belt, but consisting mainly of objects composed primarily of ice. It extends between 30 and 50 AU from the Sun. It is composed mainly of small Solar System bodies, although the largest few are probably large enough to be dwarf planets. There are estimated to be over 100,000 Kuiper belt objects with a diameter greater than 50 km (30 mi), but the total mass of the Kuiper belt is thought to be only a tenth or even a hundredth the mass of Earth. Many Kuiper belt objects have satellites, and most have orbits that are substantially inclined (~10°) to the plane of the ecliptic.
  
  The Kuiper belt can be roughly divided into the " classical " belt and the resonant trans-Neptunian objects. The latter have orbits whose periods are in a simple ratio to that of Neptune: for example, going around the Sun twice for every three times that Neptune does, or once for every two. The classical belt consists of objects having no resonance with Neptune, and extends from roughly 39.4 to 47.7 AU. Members of the classical Kuiper belt are sometimes called "cubewanos", after the first of their kind to be discovered, originally designated 1992 QB, (and has since been named Albion); they are still in near primordial, low-eccentricity orbits.
  
  Currently, there is strong consensus among astronomers that five members of the Kuiper belt are dwarf planets. Many dwarf planet candidates are being considered, pending further data for verification.