Kuiper Belt

The Kuiper belt ( /ˈkaɪpər/ rhyming with "viper"), sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, although it 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 the Solar System's formation. While most asteroids are composed primarily of rock and metal, Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia and water. The classical belt is home to at least three dwarf planets: Pluto, Haumea, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, are also believed to have originated in the region.

Since the belt was discovered in 1992, the number of known Kuiper belt objects (KBOs) has increased to over a thousand, and more than 100,000 KBOs over 100 km (62 mi) in diameter are believed to exist. The Kuiper belt was initially thought to be the main repository for periodic comets, those with orbits lasting less than 200 years. However, studies since the mid-1990s have shown that the classical 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.

The Kuiper belt should not be confused with the hypothesized Oort cloud, which is a thousand times more distant. 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 known member of the Kuiper belt, and the second largest known TNO, after the scattered-disc object Eris. 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" which share the same 2:3 resonance with Neptune. In Pluto's honor, the four currently accepted dwarf planets beyond Neptune's orbit are called "plutoids".

Read more about Kuiper Belt:  History, Origins, Structure, Composition, Mass and Size Distribution, Scattered Objects, Largest KBOs, Exploration, Other Kuiper Belts

Other articles related to "kuiper belt, belts":

Haumea Family - Formation and Evolution
... not be the only elongated, rapidly rotating, large object in the Kuiper belt ... has since shifted many objects from the Kuiper belt to the more distant scattered disc ... In today's sparsely populated Kuiper belt, the chance of such a collision occurring over the age of the Solar System is less than 0.1 percent ...
Planet X - Discovery of Further Trans-Neptunian Objects
... See also History of the Kuiper belt After the discovery of Pluto and Charon, no more trans-Neptunian objects (TNOs) were found until (15760) 1992 QB1 ... Most are now recognised as part of the Kuiper belt, a swarm of icy bodies left over from the Solar System's formation that orbit near the ecliptic plane beyond Neptune ... Pluto itself is now recognized as being a member of the Kuiper belt and the second largest dwarf planet after Eris ...
Nice Model - Solar System Features - Formation of The Kuiper Belt
... Originally, the Kuiper belt was much denser and closer to the Sun, with an outer edge at approximately 30 AU ... explain the occupancy of current orbital resonances in the Kuiper belt, particularly the 25 resonance ... As Neptune migrated outward, it approached the objects in the proto-Kuiper belt, capturing some of them into resonances and sending others into chaotic orbits ...
Other Kuiper Belts
... By 2006, astronomers had resolved dust disks believed to be Kuiper belt-like structures around nine stars other than the Sun ... They appear to fall into two categories wide belts, with radii of over 50 AU, and narrow belts (like our own Kuiper belt) with radii of between 20 and 30 AU and relatively ... have an observed infrared excess which is believed to indicate massive Kuiper belt-like structures ...
List Of The Brightest Kuiper Belt Objects
... Since the year 2000, a number of Kuiper belt objects (KBOs) with diameters of between 500 and 1500 km (more than half that of Pluto) have been discovered ... This has led gradually to the acceptance of Pluto as the largest member of the Kuiper belt ...

Famous quotes containing the word belt:

    The shore is composed of a belt of smooth rounded white stones like paving-stones, excepting one or two short sand beaches, and is so steep that in many places a single leap will carry you into water over your head; and were it not for its remarkable transparency, that would be the last to be seen of its bottom till it rose on the opposite side. Some think it is bottomless.
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