1. Introduction. 1.1. Relevance of Planetary Geology. 1.1.1. Origin and Evolution of the Solar System. 1.1.2. Origin and Evolution of Life. 1.1.3. Our Terrestrial Environment. 1.2. The Planetary Geology Approach. 1.2.1. Present Geologic State. 1.2.2. Geological Evolution of Planets. 1.3. Comparative Planetology.

2. Surface Features and Processes. 2.1. Structural Geology and Tectonics. 2.1.1. Basic Questions. 2.1.2. Geologic Maps. 2.1.3. Experimental Stress/Strain Studies. 2.1.4. Stress Field Indicators. 2.1.5. Tectonic Energy and the Generation of Stress Fields. 2.1.6. Methodology. 2.1.7. Summary. 2.2. Volcanism. 2.2.1. Geomorphology of Volcanic Landforms. 2.2.2. Modeling of Volcanic Processes. 2.2.3. Experimental Petrology. 2.2.4. Summary. 2.3. Cratering. 2.3.1. Impact Cratering: An Introduction. 2.3.2. Methods of Study. 2.3.3. Craters in Geologic Studies: Some Established and Emerging Uses. 2.3.4. Persistent Problems and Unanswered Questions. 2.3.5. Summary. 2.4. Eolian Processes. 2.4.1. Review of Eolian Activity on the Planets. 2.4.2. Relevance of Eolian Studies to Planetary Geology. 2.4.3. Suggested Approach for Investigating Eolian Processes. 2.4.4. Summary. 2.5. Fluvial Processes. 2.5.1. Water as a Geologic Agent. 2.5.2. Dynamics of Fluvial Sedimentation. 2.5.3. Channel and Valley Morphology on Mars. 2.5.4. Summary. 2.6. Mass Movement. 2.6.1. Mass Movement on Earth. 2.6.2. Mass Movement on the Moon and Mercury. 2.6.3. Mass Movement on Mars. 2.6.4. Mass Movement on Other Bodies. 2.6.5. Summary. 2.7. Glacial and Periglacial Processes 2.7.1. Physical Properties of Water Ice of Interest to Geology. 2.7.2. Ice Masses in the Solar System. 2.7.3. Periglacial Processes on Planetary Surfaces. 2.7.4. Summary.

3. Chronology of Planetary Surface. 3.1. Absolute Dating. 3.2. Relative Dating. 3.3. Potential New Information on Solid Bodies. 3.3.1. Mercury 3.3.2. Venus... 3.3.3. Mars. 3.3.4. Asteroids. 3.3.5. Satellites of Jupiter and Saturn. 3.4. Summary.

4. Geochemistry in the Planetary Geology Context. 4.1. Information from Sample Analysis. 4.2. Information from Atmospheres. 4.3. Geochemical Clues to Surface Processes. 4.3.1. Surface Processes on Planets with Atmospheres. 4.3.2. Surface Processes on Bodies with No Atmospheres. 4.4. Examples of Key Issues and Problems. 4.4.1. Venus. 4.4.2. Mars. 4.5. Summary.

5. Geophysics in the Planetary Geology Context.: 5.1. Geological Constraints on Thermal Histories.; 5.2. Gravity and Topography Data.; 5.3. Shapes of Planets and Satellites.; 5.4. Magnetic Fields.; 5.5. Outer Planet Satellites.; 5.6. Summary.

6. Geodesy and Cartography.: 6.1. Introduction.; 6.2. Available Data Base.; 6.3. The Coordinate Systems of Planets and Satellites.; 6.4. Geometric Geodesy.; 6.5. Physical Geodesy.; 6.6. Cartography.; 6.7. Summary.

7. The Geology of Smell Bodies. 7.1. What is a Small Body?. 7.2. Inventory. 7.3. Why Study Small Bodies?.. 7.3.1. Effects of Small Bodies on Larger Objects. 7.3.2. Unique Surface Features and Processes. 7.3.3. Small Bodies as Natural Laboratories. 7.3.4. Evolution and Interrelationship. 7.4. Summary.

8. Remote Sensing and Supporting Earth-Based Studies. 8.1. Analog Studies. 8.2. Laboratory Studies. 8.2.1. Cratering. 8.2.2. Volcanic Processes. 8.2.3. Tectonics. 8.2.4. Fluvial Processes. 8.2.5. Aeolian Phenomena. 8.2.6. Cometary Processes. 8.2.7. Regolith Processes. 8.3. Remote Sensing. 8.3.1. Remote Sensing Using Earth-Based Telescopes. 8.3.2. Observations from Earth Orbit. 8.3.3. Radar and Radio Observations.

9. Summary and Recommendations. 9.1. Inner Solar System. 9.1.1. Mercury. 9.1.2. Venus. 9.1.3. Moon. 9.2. Outer Solar System. 9.2.1. Satellites of Jupiter. 9.2.2. Saturn Satellites. 9.3. Small Bodies. 9.4. Geodesy and Cartography. 9.5. Laboratory Studies and Instrumental Techniques. 9.6. Analog Studies. 9.7. Remote Sensing from Earth. 9.8. Remote Sensing of Earth. 9.9. Archiving and Dissemination of Planetary Data. 9.10. Continuity and Future of the Planetary Geology Program.

References.