<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Kuiper belt (/ ˈkaɪpər / or Dutch pronunciation: (' kœy̯pər)), occasionally called the Edgeworth--Kuiper belt, is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun . It is similar to the asteroid belt, but is far larger--20 times as wide and 20 to 200 times as massive . Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed . While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia and water . The Kuiper belt is home to three officially recognized dwarf planets: Pluto, Haumea and Makemake . Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region . </P> <P> The Kuiper belt was named after Dutch - American astronomer Gerard Kuiper, though he did not predict its existence . In 1992, Albion was discovered, the first Kuiper belt object (KBO) since Pluto and Charon . Since its discovery, the number of known KBOs has increased to over a thousand, and more than 100,000 KBOs over 100 km (62 mi) in diameter are thought to exist . The Kuiper belt was initially thought to be the main repository for periodic comets, those with orbits lasting less than 200 years . Studies since the mid-1990s have shown that the belt is dynamically stable and that comets' true place of origin is the scattered disc, a dynamically active zone created by the outward motion of Neptune 4.5 billion years ago; scattered disc objects such as Eris have extremely eccentric orbits that take them as far as 100 AU from the Sun . </P> <P> The Kuiper belt is distinct from the theoretical Oort cloud, which is a thousand times more distant and is mostly spherical . The objects within the Kuiper belt, together with the members of the scattered disc and any potential Hills cloud or Oort cloud objects, are collectively referred to as trans - Neptunian objects (TNOs). Pluto is the largest and most massive member of the Kuiper belt, and the largest and the second-most - massive known TNO, surpassed only by Eris in the scattered disc . Originally considered a planet, Pluto's status as part of the Kuiper belt caused it to be reclassified as a dwarf planet in 2006 . It is compositionally similar to many other objects of the Kuiper belt and its orbital period is characteristic of a class of KBOs, known as "plutinos", that share the same 2: 3 resonance with Neptune . </P>

Kupier belt objects (kbos) are comets found