Satellites Of The Outer Planets

Extensively revised and updated, this new edition of David A. Rothery's acclaimed geological guide to the outer solar system includes results and close-up color and black and white images from both the 1995-1999 Galileo mission to Jupiter and the Voyager space probe. Rothery, a noted planetary scientist, explains the geological aspects of the major satellites of the outer planets, from Jupiter to Neptune and the Pluto-Charon system. In particular he shows how tectonic and volcanic processes, driven by heat from within, have shaped the rigid outer layers of these worlds. Rothery also discusses the similarities and differences among them and the ways in which they resemble Earth-like planets. This fascinating book is written in an introductory style ideal for first- or second-year college courses. Amateur geologists and astronomers will also find its insights rewarding.

One of the most fundamental discoveries of the solar system was the detection of four moons in orbit around Jupiter by Galileo Galilei in 1610. The discovery was significant not only in the context of Jupiter; it gave credence to and was instrumental in firmly establishing the heliocentric system of Nicolaus Copernicus. Almost four centuries after Galileo's discovery, exten sive observations by the two Voyager spacecrafts have once again revolu tionized our thinking about the major planets, their composition, structure, origin, and evolution. This book is an attempt at summarizing our present understanding of the atmospheres and ionospheres in the outer solar system, with particular emphasis on the relevant physics and chemistry. I was motivat ed to prepare this manuscript for the following reasons. First, after under going rapid expansion in the recent past, the subject has finally attained suf ficient maturity to warrant a monograph of its own. Second, I have felt that as a result of recent observations, new and challenging problems have arisen whose resolution requires unconventional analysis and theoretical interpreta tion of existing data, as well as the collection of new kinds of data. I believe the time is ripe to put these issues in the appropriate scientific perspective, with the hope of stimulating novel theoretical, observational, and laboratory studies. I have highlighted the significant scientific problems throughout the book, especially at the end of each chapter.

As our ability to observe space improves with ever-progressing technology, we better grasp the farthest reaches of the cosmos and heighten our understanding of the universe in its entirety. Spacecraft exploration of the outermost planets in our solar system—Jupiter, Saturn, Uranus, and Neptune—reveals many features of these seemingly harsh environments and moves us closer to comprehending the origins of our own planet as well as others. This insightful volume examines the characteristics of these remote planets and the paths they illuminate in our quest for celestial knowledge.

Recent space missions to the outer solar system, Galileo (1996–2003) and Cassini-Huygens (2004–today), together with ground observations, have revealed that the moons of the outer solar system are enigmatic objects, introducing extraordinary challenges for geologists, astrobiologists, organic chemists, and planetologists. Chemical exchange exists through the different layers that form their interiors, and also from the interior to the surface. The most convincing evidence is certainly the discovery of water vapour and ice particles emerging from Enceladus’s active south polar region. Evidence for exchange with a subsurface liquid ocean has also been provided by the inference of hydrated salts on the surfaces of Jupiter’s moons, Europa and Ganymede, as well as the detection of sodium salts in particles originating in Enceladus’s plumes. Aqueous exchange with the rocky core may also be possible, considering that 40Ar has been observed in the plumes of Enceladus during one flyby of Cassini and in the atmosphere of Titan. The ongoing CH4 replenishment in Titan’s atmosphere is additional striking evidence of exchange processes within the moons.

For centuries, astronomers have placed a special interest on the other planets of the solar system. But with the advent of spacecraft and the tremendous missions undertaken by the Voyager and Cassini probes, astronomers have discovered that the natural satellites of the planets—the solar system's moons—are some of the most extraordinary places imaginable. There are moons with towering geysers, erupting volcanoes, and subterranean oceans of warm, mineral-rich water. Some of the highest mountains and deepest canyons can be found on the moons. There are moons that have shattered into pieces and then reassembled. There is even a moon where it rains rocket fuel. Recently, scientists have turned to the moons for answers in their investigations of the origins of the solar system and the evolution of life on our own planet. Featuring full-color, scientifically accurate illustrations by NASA artist Ron Miller, Natural Satellites: The Book of Moons chronicles these investigations and the questions we have yet to answer in our exploration of the solar system's moons.

Representatives of several scientific communities, such as planetary scientists, astronomers, space physicists, chemists and astrobiologists have met with the aim to review the knowledge on four major themes: (1) the study of the formation and evolution processes of the outer planets and their satellites, beginning with the formation of compounds and planetesimals in the solar nebula, and the subsequent evolution of the interiors of the outer planets, (2) a comparative study of the atmospheres of the outer planets and Titan, (3) the study of the planetary magnetospheres and their interactions with the solar wind, and (4) the formation and properties of satellites and rings, including their interiors, surfaces, and their interaction with the solar wind and the magnetospheres of the outer planets. Beyond these topics, the implications for the prebiotic chemical evolution on Europa and Titan are reviewed. At the time of publication, the study of the outer planets is particularly motivated by the fact that the Saturn system is being investigated by the Cassini-Huygens mission.