KUIPER BELT OBJECTS

The Kuiper Belt, named after the Dutch Astronomer Gerald Kuiper is a region in the solar system which extends from the planet Neptune. The trans-Neptunian region of the solar system is now known to contain  a  vast  population  of  icy  bodies  and this has been called  the  Kuiper Belt,  first  discovered  by David  Jewitt  and  Jane  Luu  in August of 1992. The discovery confirmed that the region immediately  beyond  the  planets  is  not  merely  empty space but  is  instead  richly populated with a vast  reservoir  of  fossil  remnants  from  the  original  solar  nebula. The enormous scientific potential of the Kuiper Belt was soon recognized and the belt is now the subject of intensive observational and dynamical studies.

It is similar to the asteroid belt lying between Mars and Jupiter, although it is a lot larger - about 20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small objects, or remnants from the Solar System's formation. While the asteroid belt is composed mainly of rocks and metals, the Kuiper belt is composed largely of frozen volatiles (termed "ices"), such as methane, ammonia and water. It is home to three dwarf planets – the recently added Pluto, Haumea, and Makemake.

Neptune defines the inner edge of the Kuiper Belt. While the outer edge of the belt remains unknown, it is known that the belt extends at least as far as ~130 AU.  Researchers have counted 346 Kuiper belt objects (KBOs) since they were first recognized in the early 1990s, but, assuming a 4% albedo for the ones known, it is estimated currently that  there  are  at  least  70 000  of  them with diameters larger than 60 mi (100 km). Based on their dynamics, the known KBOs can be divided roughly into three distinct categories:  the classical KBOs, the resonance KBOs and the scattered KBOs.

Pluto is the largest known member of the Kuiper belt. Originally considered as a planet, Pluto's position in the Kuiper belt has caused it to be redefined as a "dwarf planet". Its composition is similar to many other objects of the Kuiper belt, and its orbital period is also similar to that of the KBOs known as "plutinos". In Pluto's honor, the four currently accepted dwarf planets beyond Neptune's orbit are called "plutoids".

Questions to Ponder

• Are Kuiper Belt Objects asteroids?
• Are there any Planets among Kuiper Belt Objects?