At the distant edges of the Solar System are planets Neptune and Uranus, dwarf planets such as Pluto, and other orbiting bodies. This book includes the latest discoveries about all these far-off objects, including the first close-up pictures taken of Pluto. What are these worlds like that live so far from the heat of the sun? How were they formed? Why is Neptune blue? And why did Pluto lose its place as a planet? The mysteries of these far-off worlds are all revealed inside.