Recent events such as the impact of the Schumacher-Levy comet into Jupiter have pushed planetary science into the forefront of public attention, and underlined the progress that the subject has made in recent years. This comprehensive work contains over 500 entries covering important features of all the planets, their environments, and the processes that have shaped them. Techniques and methods such as spectroscopy, photometry and radiometry are covered in detail, and the history of planetary science is represented by entries on key individuals, as well as broader topics such as the major planetary missions, remote sensing and so on. This book should be of interest to professional planetary scientists, geologists, astronomers, space scientists and atmospheric scientists. Included is a CD-ROM of images taken from the Hubble space station.