Final answer:
The Oort Cloud is a spherical shell of cometary nuclei far beyond the Kuiper Belt, reaching up to 50,000 AU and acting as a source for long-period comets. The Kuiper Belt is a disk-shaped region beyond Neptune, extending to 50 AU, and is the source of short-period comets. The study of these regions helps us understand the origins and composition of comets in our Solar System.
Step-by-step explanation:
The Oort Cloud is a vast spherical shell of cometary nuclei that exists far beyond the orbits of the planets, including Neptune and the Kuiper Belt. The main function of the Oort Cloud is to serve as a reservoir for long-period comets. It stretches out to about 50,000 astronomical units (AU) from the Sun, reaching near the limit of the Sun's gravitational sphere of influence. The cloud is believed to contain between 1012 and 1013 comets, serving as a source of new comets that can be perturbed by gravitational interactions and sent into the inner Solar System.
In comparison, the Kuiper Belt is a disk-shaped region that exists beyond Neptune's orbit and extends to approximately 50 AU from the Sun. It is the source of short-period comets and is made up of ice-and-rock planetesimals, the remnants of the building blocks of the planets. The difference in composition between Kuiper Belt Objects (KBOs) and Oort Cloud objects is of great interest to astronomers.
While many comets have been studied from both the Kuiper Belt and the Oort Cloud, occurrences such as the collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 highlight the volatile and dynamic nature of these ancient celestial bodies.