The Kupier Belt and the Oort Cloud

As the science of optics continues to advance, the scientific community is able to probe further and further into the universe. They are able to identify and classify celestial bodies that have previously been undetectable. One such organization of celestial bodies is the Kuiper belt.

Kuiper Belt

The Kuiper belt is a disk shaped region of icy debris about 30-50 AU from the Sun, which is outside the orbit of Neptune. It is similar in organization to the asteroid belt although it is far larger being 20 times as wide and 20-200 times as massive. Although similar in organization, the make up of the individual bodies is markedly different. The asteroid belt is similar to terrestrial planets being made mostly of rock and metal while the Kuiper Belt Objects (KBOs) share a similarity with the Jovian planets being made principally of frozen volatiles such as methane, ammonia, and water. The Kuiper belt is also the home of the dwarf planets Pluto, Haumea, and Makemake.

The existence of objects beyond the Neptunian orbit was first theorized in 1930 by Frederick C. Leonard soon after Pluto’s discovery. The theory continued to evolve over the next 60 years. Ironically, Gerald Kuiper, influential astronomer of the 20th century, whom the belt is named for, believed that such a disc of astronomical bodies may have formed early in the Solar System’s early evolution, but that the belt did not exist today. In 1992, an object in the belt was discovered by astronomer David Jewett. Six months later, Jewett’s team discovered a second trans-Neptunian object (TNO). The number of identified KBOs has increased to over a thousand and more than 70,000 KBOs are believed to exist within the belt.

Oort Cloud

The Kuiper belt is not the only believed source of TNOs. Another organized structure of astronomical bodies has been theorized to exist called the Oort cloud, named for Jan Oort who originally theorized its existence in 1950. Light is so scarce in the far reaches of the proposed solar system that it is extremely difficult to identify the existence the cloud. The main evidence for the belt is the passage of long-period comets that pass through the inner solar system only once. The Oort cloud is home to astronomical bodies that vary in size from 50km to the size of Pluto. It has been theorized that several there might be larger bodies within the Oort cloud as well.

Celestial bodies within the Kuiper belt and the Oort cloud continue to spur on the study of deep space. As it stands now, no spacecraft has left the bounds of the known solar system, but that is slated to change in 2015. The unmanned craft, New Horizons, will arrive at Pluto in 2015 and begin the exploration of the dwarf planet and its moons as well as exploring further into the Kuiper belt. With the exciting advances in optics and long range study devices such as New Horizons, the understanding of the outlying areas of the solar system will continue to bring further insight into Earth’s small corner of the galaxy and the universe as a whole.

New Horizons Mission

References

http://solarsystem.nasa.gov/planets/profile.cfm?Object=KBOs

http://solarsystem.nasa.gov/planets/profile.cfm?Object=OortCloud

http://www.nasa.gov/mission_pages/newhorizons/main/index.html