The Kuiper Belt, also known as the Edgeworth-Kuiper Belt, is a region that extends beyond the orbit of the planet Neptune to approximately 50 astronomical units (AU) from the sun. It is composed of small bodies and components from the formation of the solar system – think of it like the asteroid belt, but only larger (20 times as wide and 200 times as massive).
Although experts had hypothesized of such a belt, the first evidence of the Kuiper Belt was discovered in 1992, but due to the nature of the discovery and the constant speculations, no one person has taken direct credit for its finding.
For two decades, there has been numerous known Kuiper Belt Objects (KBOs). It is estimated that since 1992, more than 70,000 KBOs are thought to exist (35,000 with a diameter greater than 100km). The Kuiper Belt consists mostly of icy debris of numerous substances and particles with similar constitution to comets – a combination of ammonia, frozen water and hydrocarbons.
Even though it used to be considered a planet and now a dwarf planet, Pluto is the largest object in the region. Also, other objects should be noted that are substantially large: Quaoar – half the size of Pluto – and Makemake and Haumea – approximately the size of Pluto. A distinctive sum of these KBOs contains satellites, such as Eris, Pluto and Haumea.
After years of research, the Kuiper Belt is now believed to be the source of short-period comets (orbits lasting 200 years) – similar to the Oort Cloud, but must not be confused with the Kuiper Belt. However, it is important to note that the orbit of a KBO could be distorted due to interactions with giant planets, which would force an object to orbit Neptune.
The Kuiper Belt is also made up of different regions. For example, a densely populated area of the Kuiper Belt is identified as the classical Kuiper Belt and is about 45 AU from the sun. Neptune’s gravitational affect does not hinder the region, which leads to objects remaining stable within their own orbits.
No spacecraft has yet to study the Kuiper Belt first hand, but NASA’s New Horizons, launched in January of 2006, will research the region following its in-depth study of Pluto. For many space-enthusiasts, though, they will have to wait quite some time. The mission will not reach Pluto until the year 2015, while investigations of KBOs will take much longer too.