Kuiper Belt

Article By:

Sheppard, Scott Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC.

Last reviewed:February 2019

DOI:https://doi.org/10.1036/1097-8542.757509

Show previous versions

• Kuiper Belt, published February 2019:Download PDF Get Adobe Acrobat Reader
• Kuiper Belt, published March 2014:Download PDF Get Adobe Acrobat Reader

A reservoir of icy bodies just beyond the orbit of the planet Neptune. The Kuiper Belt (Fig. 1) is the largest observed relatively stable ensemble of small bodies in the planetary region, outnumbering the rocky main-belt asteroids between Mars and Jupiter by a factor of a few hundred, with estimates of the total number of objects running into the millions. The Kuiper Belt's vast distance from the Sun suggests the objects are chemically primitive, containing large amounts of volatiles such as water ice. The short-period comets, which generally have low inclinations, are objects that were once in the Kuiper Belt. The Kuiper Belt objects (KBOs) are leftover pieces from the original solar nebula out of which our Sun and planetary system formed. Understanding the physical and dynamical evolution of the Kuiper Belt is important in determining how the planets formed and moved about in the past. Evidence of Kuiper Belts in other solar systems suggests these reservoirs of objects are natural, common phenomena in the universe. See also: Asteroid; Comet; Exoplanet; Jupiter; Mars; Neptune; Planet; Solar system

The content above is only an excerpt.