Preface

Planetary geoscience had its inception with the birth of the Space Age in the early 1960s. In the ensuing decades, it has evolved into a discipline that is recognized by sections of professional organizations such as the Geological Society of America and the American Geophysical Union, as well as being taught at the university level. Much of our understanding of the geology of extraterrestrial objects is derived from remote sensing data – primarily images that portray planetary surfaces. In fact, discoveries such as the dry river beds on Mars, the tectonic deformation of Venus, and the actively erupting volcanoes on Jupiter’s moon Io all came from pictures taken from spacecraft. Thus, the focus of this book is on the geomorphology of solid-surface objects in our Solar System and the interpretations of the processes that led to the diverse landforms observed. Geomorphology, however, must be analyzed in the context of broader geoscience; consequently, in the chapters on the individual planetary systems, the geophysics and interior characteristics are reviewed along with our current understanding of surface compositions and the general geologic histories. Of course, our knowledge of the Solar System is far from uniform from one planet to another, dependent upon the numbers and types of spacecraft that have returned data. Thus, the chapters on the Moon and Mars are more detailed than those on the outermost planet systems, Uranus and Neptune, because dozens of successful spacecraft have visited our nearest planetary neighbors, in contrast to the limited data returned from “flybys” of the Voyager spacecraft to the planets beyond Saturn.

Our journey to explore the geomorphology of the Solar System begins with introductory chapters that introduce the planets and other objects of planetary geoscience interest, discuss the methods used in studying extraterrestrial objects, and review the fundamental geomorphic processes on Earth that can be compared with what we see on other planets and satellites.