Physics and Chemistry of Comets

1. Introduction.- 1.1 Plan of the Book.- 1.2 General Concepts.- 1.3 Orbits of Some Comets for Spacecraft Missions.- 1.4 The Oort Cloud Compared to the Planetary Orbits.- 1.5 Summary of Spacecraft Data from Comets.- 1.6 Summary of New Data from Remote Sensing.- 1.7 Reasons for Planned and Proposed Comet Missions.- 1.8 Laboratory and Space Experiments and Simulations.- 2. The Nucleus.- 2.1 Introduction.- 2.2 Observational Techniques.- 2.3 Models of the Nucleus.- 2.4 The Nucleus of Comet P/Halley.- 2.5 Modeling and Laboratory Experiments.- 2.6 Physical Parameters of the Nucleus.- 2.7 Summary.- 3. The Neutral Coma.- 3.1 Introduction.- 3.2 The Coma: A Transient Phenomenon.- 3.3 Excitation and Emission Mechanisms.- 3.4 Composition of the Coma.- 3.5 Summary and Prospectus.- 4. Dust.- 4.1 Introduction.- 4.2 What is Comet Dust?.- 4.3 Dust Release from the Nucleus.- 4.4 Dust Emission.- 4.5 Dust Coma Structure.- 4.6 Dust Tails.- 4.7 Mass Distribution.- 4.8 Optical and Infrared Properties.- 4.9 Dust Composition.- 4.10 Dust Production Rate and the Dust to Gas Ratio.- 4.11 Summary.- 5. The Plasma.- 5.1 Introduction.- 5.2 Large-Scale Processes of the Solar Wind-Comet Interaction.- 5.3 Ion Composition.- 5.4 Ionospheric Processes.- 5.5 Plasma Wave Turbulence.- 5.6 Ion Acceleration.- 6. Orbital Distribution of Comets.- 6.1 Introduction.- 6.2 Origin and Dynamical Evolution.- 6.3 Time Scales.- 6.4 The Outer Part of the Presolar Nebula.- 6.5 The Distribution of the Reciprocal Semimajor Axes.- 6.6 Other Theories for the Origin and Evolution.- 6.7 Short-Period Comets.- 6.8 Differences Between Long- and Short-Period Comets.- 7. Comet Formation and Evolution.- 7.1 Introduction.- 7.2 Chemical and Physical Clues from Observations.- 7.3 Formation of Comet Nuclei.- 7.4 Dynamical Evolution of Comets.- 7.5 Physical Evolution of Comet Nuclei.- 7.6 Summary.- 8. Implications of Comet Research.- 8.1 Introduction.- 8.2 Progress in Physics and Chemistry of Comets.- 8.3 Progress on the History of the Early Solar System.- 8.4 Comets and the Origins of Life.- 8.5 Unsolved and New Problems.- References.