Unlike all the planets closer to the Sun, known since antiquity, the farthest reaches are discoveries of the modern world. Uranus was discovered in 1781; Neptune, 1846; Pluto, 1930; the Kuiper belt group of objects, 1992; and though the Oort cloud had been theorized since 1950, its first member was just found in 2004. The discovery of the outer planets made such an impact on mankind that they were immortalized in the names of the newly discovered elements: uranium, neptunium, and plutonium. In a single, informative reference, "Uranus, Neptune, Pluto, and the Outer Solar System" discusses what data there is on the distant gas planets and investigates theories about their formation and evolution. It also touches on the fact that Pluto and its moon Charon are part of a much larger population of icy and rocky bodies now known as the Kuiper belt and describes what is known about the Oort cloud, along with the reasoning that led to its theorization and the technology that has allowed its actual discovery. Perfect for those interested in understanding the science and history behind the exploration of these celestial bodies, this volume brings the mystery of the outer solar system to the forefront.