Since the first edition of this book appeared in print, infrared observations have been responsible for a number of significant new results from many objects in the Solar System. Besides highly sophisticated ground-based measurements, instruments on space probes such as Galileo, Mars Global Surveyor, Vega, Giotto, Phobos-2, the Infrared Space Observatory, and others have produced new data leading to interesting conclusions. Even the spectacular impact of comet Shoemaker–Levy 9 yielded unique information on the atmosphere of Jupiter as well as on the structure of comets. More refined analyses of older data sets have also contributed new insight.

Clearly, an identical reprint of the first edition would have been out of date. To bring the book up to the present state of the art it was necessary to incorporate the latest results. Although discussion of the Solar System bodies has been broadened by including Pluto, comets, and asteroids, the basic format and structure of the book has been preserved. The first four chapters, dealing primarily with fundamental aspects, radiative transfer theory, molecular physics, and modeling of atmospheric spectra, have not been affected by new information. Only minor changes have been made to the text, in some cases to correct errors, in others to clarify certain points. The latest results have been added primarily to Chapters 5 through 9. Some new instrumental techniques needed to be included. More recent information on atmospheric composition and structure had to be compared to older results.