Giant as it is, Neptune is so remote that it is below naked-eye visibility and so was not discovered until the development of the telescope. As the most distant major planet in the solar system, Neptune was the last to be visited by a spacecraft from Earth. The encounter of NASA's Voyager 2 spacecraft with Neptune in August 1989 has provided a wealth of new information about the planet, its ghostly rings, remarkable satellites and environment, and has led to some amazing discoveries. This book gives the fascinating historical background to the discovery of Neptune, its satellites and rings and goes on to describe the Voyager mission in detail. This allows the reader to appreciate the dramatic leap in the knowledge and understanding of the Neptunian environment that planetary scientists found from the Voyager flyby. All the latest information is given, illustrated with the definitive pictures from the NASA mission. No more visits by space-probes to the outer planets are likely for several decades; this book therefore represents a timely summary of our knowledge of Neptune of lasting value and enjoyment to professionals and amateurs alike.