Kuiper belt

Kuiper Belt A region of the outer Solar System containing an estimated 10⁷ − 10⁹ icy planetesimals, or comet nuclei. The Kuiper Belt is an inner, flattened extension of the Oort Cloud. It lies more or less in the same plane as the planets and extends outwards from around 30 AU (the orbit of Neptune) to perhaps 1000 AU. Members of the Kuiper Belt are also known as trans-Neptunian objects. Such a vast reservoir of comets beyond Neptune was proposed in 1951 by G. P.Kuiper. The Irish engineer and astronomer Kenneth Essex Edgeworth (1880–1972) wrote papers about objects beyond Pluto in 1943 and 1949, so it is also known as the Edgeworth–Kuiper belt. In 1992, the British-born American astronomer David Clifford Jewitt (1958– ) and the Vietnamese-born American astronomer Jane Luu (1963– ) discovered the first Kuiper Belt object, 1992 QB₁, now numbered (15760). This has a diameter of about 200 km, semimajor axis 43.8 AU, orbital period about 290 years, perihelion 40.9 AU, aphelion 46.7 AU, and inclination 2 °.2. Since then, hundreds more have been found. The Kuiper Belt is thought to be the source of most periodic comets. Members of the Kuiper Belt that pass close to Neptune can be diverted inwards by gravitational perturbations to become Centaurs, or outwards to become scattered‐disk objects. See also cubewano; plutino.

Kuiper belt A region of bodies, made mainly from ice, that lies just beyond the orbit of Pluto and supplies the solar system with short-period comets, e.g. Halley. At its outer margins the Kuiper belt extends into the Oort cloud. The existence of the Kuiper belt was proposed by Gerard P. Kuiper, in 1988 its role as the source of short-period comets was suggested, and in the early 1990s the first objects belonging to the Kuiper belt were discovered.

Edgeworth–Kuiper Belt An alternative name for the Kuiper Belt.