part.23. Oort Cloud The Mysterious Boundary of Our Solar System

Far beyond the route of Neptune, beyond the Kuiper Belt and the scattered fragment, lies a vast and mysterious realm — an nearly fabulous boundary marking the edge of our solar system. This region is known as the Oort Cloud, a globular shell of icy objects believed to compass the Sun at a distance between 2,000 and 100,000 astronomical units( AU).