FrontMatter -- Preface -- Contents -- Executive Summary -- 1 Introduction -- 2 Interior and Crustal Structure and Activity -- 3 Geochemistry and Petrology -- 4 Stratigraphy and Chronology -- 5 Surface Processes and Geomorphology -- 6 Ground Ice, Groundwater, and Hydrology -- 7 Life, Fossils, and Reduced Carbon -- 8 Lower Atmosphere and Meteorology -- 9 Climate Change -- 10 Upper Atmosphere, Ionosphere, and Solar Wind Interaction -- 11 Rationale for Sample Return -- 12 Assessment of the Mars Exploration Program -- 13 Conclusions -- Appendixes -- Appendix A The NASA Mars Exploration Program -- Appendix B Compilation of Recommendations Concerning Mars Exploration Made by COMPLEX and Other Advisory Groups -- Appendix C Acronyms.