What is a Planet?

In 2006, the International Astronomical Union (IAU) redefined what it meant to be a planet. With increasing discovery in the Kuiper Belt, and Oort Cloud, the three criteria for an object to be classified as a planet are as follows:
1. is in orbit only around a sun.
2. sufficient mass for self gravity to create circular form and motion.
3. no comparatively sized objects in or near its orbit.
This definition gave us the four terrestrial and for gas giant planets that orbit the sun. it is also why there are only exoplanets named inside the Kuiper belt. Those objects, such as Pluto, do not meet the some criteria in naming an object a planet.
The most commonly used stellar wobble and transit methods has not allowed for much indetification of exoplanets, but the following three rules have made it possible to name any planet around any star when they meet the IAU criteria, including farther out into the Kuiper Belt:
1. the mass of a planet
2. The orbital distance/ period around its parent star
3. life time of planetary system in question.







Jewitt, Dave. "Dave Jewitt: Kuiper Belt: Surfaces of Kuiper Belt Objects." Dave Jewitt: Kuiper Belt: Surfaces of Kuiper Belt Objects. N.p., n.d. Web. 01 Dec. 2015.

The New Challenge

The discovery of the Kuiper belt has lead to many more questions about the objects contained in it. Much like the classifications of the eight planets, scientists are uncovering the sizes and colors and the moons and atmospheres of Kuiper Belt Objects (KBOs). One particularly suggested questions, by previously mentions David Jewitt, is about the surface of these objects. In his studies, Jewitt has found a large array of colors using low resolution spectra data. He proposes two explanations of the wide diversity of color. First, that the diversity in color represents the diversity of the composition of objects. Second, the process of "collision resurfacing" ( impact craters create ray of light on other material, distorting color of said material), creating the diversity in color.

Further study from the scientific community has lead the the conclusion as to why the color and reflectiveness are important in obtaining information about the surface of KBOs. The variety of color identifies the composition and evolution of KBOs. Although it is still difficult to identify specific minerals and ices, the revelation of color diversity is an important step in discovering what the surfaces of KBOs are comprised of.       

Jewitt, Dave. "Dave Jewitt: Kuiper Belt: Surfaces of Kuiper Belt Objects." Dave Jewitt: Kuiper Belt: Surfaces of Kuiper Belt Objects. N.p., n.d. Web. 28 Nov. 2015.

Jewitt, Dave. "Dave Jewitt: Kuiper Belt: Surfaces of Kuiper Belt Objects." Dave Jewitt: Kuiper Belt: Surfaces of Kuiper Belt Objects. N.p., n.d. Web. 28 Nov. 2015.

What is in the Kuiper Belt?

In short, the Kuiper belt is a disc- shaped region beyond Neptune filled with innumerable icy bodies. These ices are made of frozen volatile material, or gases such as methane, ammonia, and nitrogen.  These objects are presumed to be remnants of the formation of the solar system all that time ago (4.6  billion years). They never formed planets, but dwarf planets such as Pluto, Haumea, and MakeMake.

Dave Jewitt and Jane luu were the first the identify and catalog and object further than Pluto. From then on, there was a procession and progression through the 1990's of astronomical technology that lead to many discoveries. The Hubble space craft captured a "double System" inside the Kuiper belt. Where smaller icy bodies orbit a bright object all while orbiting the sun. 

Predicting the size of the objects is difficult because of the distance of the belt itself. Most calculated diameters are assumptions from how reflective an objects surface is. Large objects like, Pluto and its moon Eris, have known sizes because of infrared observation technology (Spitzer Space Telescope). Many of the objects are named after God's and Goddesses, much like many things in the solar system.  

Dunford, Bill, and Philips Davis. "Solar System Exploration." Solar System Exploration. NASA, n.d. Web. 24 Nov. 2015.
"Kuiper Belt Facts - Interesting Facts about the Kuiper Belt." Space Facts RSS. N.p., 10 Sept. 2014. Web. 01 Dec. 2015.

Kuiper Belt Origins

What came first, the Kuiper Belt or the Oort cloud? Both were mere proposals by astronomers of the mid 20th century before the Kuiper belts direct discovery in 1992. It gets its name by the author of its proposal. In 1951, Gerard P. Kuiper developed a strong case for Kenneth E. Edgeworth's speculation of small bodies distribution throughout the solar system. working from Edgeworth's analysis of the mass distribution of spacial bodies in the creation of the solar system, Kuiper demonstrated that large residual amounts of icy, inactive comet nuclei must lie beyond Neptune. He also supported his proposal by explaining short period comets (those whose orbit the sun in less than 200 years). He explained that these comets that orbit the sun in the same direction as all the planets require a closer more flattened source than comets whose periods last longer than 20 years. It is interesting to note that Pluto was discovered 62 years before the first detection of the Kuiper belt. Because of the discovery of the Kuiper belt, Pluto, as of 2006, is considered a dwarf planet because of its location and size in the belt.





"Kuiper belt". Encyclopædia Britannica. Encyclopædia Britannica Online.
Encyclopædia Britannica Inc., 2015. Web. 24 Nov. 2015
<http://www.britannica.com/place/Kuiper-belt>.