Structure and Evolutionary History of the Solar System

This monograph is based on four papers which have been published in Astrophysics and Space Sciences 1970--1974. They contain the results of our joint work started in 1968 at the University of California, San Diego, in La Jolla. The work was based on the belief that the complicated processes by which our solar system was formed can only be clarified by close collaboration between representatives of the physical and chemical sciences. Our investigations have also been strongly supported by work at other institu­ tions, especially by a group at the Royal Institute of Technology, Stockholm, where a number of plasma experiments have been made in order to clarify basic processes which are relevant to cosmogonic problems. These experiments were, in their turn inspired by theoretical work on primordial processes carried out during the last thirty-five years. We especially want to acknowledge the contributions by Drs N. Herlofson, B. Lehnert, C.-G. Fiilthammar, and Lars Danielsson in Stockholm and by Drs J.

I. General Principles and Observational Facts.- 1. Introduction and Survey.- 1.1. Structure of the Solar System.- 1.2. The Approach to the Evolutionary History.- 1.3. Planetary System and Satellite Systems.- 1.4. Infrared Stars.- 1.5. Plasma Phenomena.- 1.6. The Actualistic Approach.- 1.7. The Main Features of Evolutionary Processes.- 1.8. Planetary Cosmogonies.- 2. The Orbits of Planets and Satellites.- 2.1. Different Presentations of Celestial Mechanics.- 2.2. Circular Orbits.- 2.3. Oscillation.- 2.4. Coulomb Force.- 2.5. Large Eccentricity.- 2.6. Motion in the Field of a Rotating Central Body.- 2.7. Planetary Motion Perturbed by Other Planets.- 2.8. Orbital Properties of Planets and Satellites.- 2.9. Physical Properties of Planets and Satellites.- 2.10. Other Quantities of Hetegonic Importance.- 2.11. Mass Distribution in the Solar System.- 2.12. Laplacian Model vs Real Conditions.- 2.13. Titius-Bode’s ‘Law’.- 3. The Small Bodies.- 3.1. Forces Acting on Small Bodies.- 3.2. Production of Small Bodies: Fragmentation, Condensation and Accretion.- 3.3. Radiation Pressure. Poynting-Robertson Effect.- 3.4. Viscosity (Collisions).- 3.5. A Basic Mistake.- 3.6. Jet Streams.- 3.7. Collisions Between a Grain and a Jet Stream.- 3.8. Size Spectra.- 3.9. Three Simple Models.- 3.9.1. Non-Gravitational Accretion.- 3.9.2. Gravitational Accretion.- 3.9.3. Fragmentation.- 3.10. Asteroids.- 3.10.1. General Survey.- 3.11. Hirayama Families and Jet Streams.- 3.12. Subvisual Asteroids.- 3.13. Comets.- 3.14. Short-Period Comets.- 3.15. Meteoroids.- 3.16. Relation Between Comets and Meteoroids.- 3.17. Relation Between Asteroids and Comets-Meteoroids.- 4. Resonance Structure.- 4.1. Resonance and the Oscillation of a Pendulum.- 4.2. A Simple Resonance Model.- 4.3. Deviations from Exact Resonance.- 4.4. Resonances in the Solar System.- 4.5. Different Types of Resonances.- 4.6. Orbit-Orbit Resonances in Satellite Systems.- 4.7. On the Absence of Resonance Effects in the Saturnian Ring System.- 4.8. Orbit-Orbit Resonances in the Planetary System.- 4.9. Spin-Orbit Resonances.- 4.10. Near-Commensurabilities.- 4.11. Theory of Resonances.- 5. Spin and Tides.- 5.1. Tides.- 5.2. Amplitude of Tides.- 5.3. Tidal Braking.- 5.3.1. Fluid Body.- 5.3.2. Solid Body.- 5.3.3. Structured Bodies.- 5.4. Satellite Braking of Planetary Spins.- 5.5. Solar Tide Braking of Planetary Spin.- 5.6. Tidal Evolution of Satellite Orbits.- 5.7. The Isochronism of Spins.- 5.8. Conclusions from the Isochronism.- 6. Post-Accretional Changes in the Solar System.- 6.1. Stability of Orbits.- 6.2. Constancy of Spin.- 6.3. On the Possibility of Reconstructing the Hetegonic Processes.- References.- II. Accretion of Celestial Bodies.- 7. Formation of Celestial Bodies.- 7.1. Gravitational Contraction of a Gas Cloud.- 7.2. Condensation and Angular Momentum.- 7.3. The Early Stage of Accretion (Embryonic Growth).- 7.4. Objections to the Embryonic Accretion Mechanism.- 7.5. Accretion of Resonance Captured Grains.- 7.6. Properties Required of the Accretional Process.- 7.7. The Eccentricity of the Grain Orbits.- 7.8. Comparison with the Present State in the Asteroidal Belt.- 8. Spin and Accretion.- 8.1. Grain Impact and Spin.- 8.2. Accretion from Circular Orbits by a Non-Gravitational Embryo.- 8.3. Gravitational Accretion.- 8.4. Giuli’s Theory of Accretion.- 8.5. Statistical Theory of the Accretion.- 9. On the Accretion of Planets and Satellites.- 9.1. Embryonic Accretion.- 9.2. Jet Stream as an Intermediate Step in the Formation of Planets and Satellites.- 9.3. Accretion of an Embryo.- 9.4. Accretion in a Medium of Constant Density.- 9.5 Mass Balance of the Jet Stream.- 9.6. Energy Balance in a Jet Stream.- 9.7. Accretion when the Injection in the Jet Stream is Constant.- 9.8. Numerical Values.- 9.9. Temperature of Accreted Body.- 9.10. Conclusions About the Temperature Structure of Planets.- 9.11. The Accretional Heat Front.- 9.12. Segregation Effect of the Accretional Heat Front.- References.- III. The Plasma Phase.- 10. Plasma Physics and Hetegony.- 10.1. Summary of Parts I and II and Plan for Parts III and IV.- 10.2. Relation Between Experimental and Theoretical Plasma Physics.- 10.3. The First and Second Approach to Cosmic Plasma Physics.- 10.3.1. General Considerations.- 10.3.2. Ionized Gas vs Plasma.- 10.3.3. Some Laboratory Results Relevant to Cosmic Physics.- 10.4. The Strategy of the Analysis of Hetegonic Plasmas.- 10.5. Required Properties of a Model.- 10.6. Some Existing Theories.- 11. Model of the Hetegonic Plasma.- 11.1. Magnetized Central Body.- 11.2. Angular Momentum.- 11.3. The Transfer of Angular Momentum.- 11.3.1. A Simplified Model.- 11.3.2. Discussion of the Model.- 11.4. The Support of the Primordial Cloud.- 11.5. The Plasma as a Transient State.- 11.6. Conclusions About the Model.- 11.7. The Hetegonic ‘Nebula’.- 11.8. Irradiation Effects.- 11.9. The Model and the Hetegonic Principle.- 12. Transfer of Angular Momentum and Condensation of Grains.- 12.1. Ferraro Isorotation and Partial Corotation.- 12.2. Orbital Motion of Plasma Under the Action of Gravitation and Centrifugal Force.- 12.3. Partial Corotation of Magnetic Plasma.- 12.4. Discussion.- 12.5. Condensation of the Plasma: The Two-Thirds Law.- 12.6. Energy Release at the Angular Momentum Transfer.- 13. Accretion of the Condensation Products.- 13.1. Survey.- 13.2. Evolution of Orbits Due to Collisions.- 13.3. The Roche Limit.- 13.4. Model of Orbit Development.- 13.5. Accretion Inside RM.- 13.6. Structure of the Saturnian Rings.- 13.6.1. The Resonance Theory of the Ring Structure.- 13.6.2. Can the Structure of the Saturnian Rings be of Hetegonic Origin ?.- 13.6.3. Hetegonic Theory of the Saturnian Rings.- 13.6.4. Theory of Cassini’s Division.- 13.6.5. Theory of the Limit Between the B and C Rings.- 13.6.6. Discussion.- 13.6.7. The Discovery of Janus.- 13.7. Accretion Outside RM.- 13.8. Formation of the Asteroid Belt.- 13.9. Conclusions About Partial Corotation.- 13.10. Satellite and Planet Formation.- 13.10.1. The Groups.- 13.11. The Accretion of Volatile Substances.- References.- IV. Chemical Differentiation. The Matrix of the Groups of Bodies.- 14. Chemical Compositions in the Solar System.- 14.1. Survey.- 14.2. Sources of Information About Chemical Composition.- 14.2.1. Surface Layers and Atmospheres.- 14.2.2. Bulk Composition.- 14.3. Chemical Differentiation Before and After the Accretion of Bodies in the Solar System.- 14.4. Unknown States of Matter.- 14.4.1. Matter at High Pressure.- 14.4.2. Grain Aggregates.- 14.5. The Composition of Planets and Satellites.- 14.5.1. Earth.- 14.5.2. Mercury.- 14.5.3. Venus.- 14.5.4. Moon and Mars.- 14.5.5. Asteroids.- 14.5.6. Jupiter and Saturn.- 14.5.7. Uranus and Neptune.- 14.5.8. Triton.- 14.5.9. Pluto.- 14.5.10. Bulk Density in Relation to Planetary Mass.- 14.5.11. Composition of Satellites.- 14.6. Composition of the Sun.- 14.6.1. Spectrometric Analysis.- 14.6.2. Analysis of Corpuscular Radiation from the Sun.- 14.6.3. Significance of Solar Abundance Data.- 14.7. Regularity of Bulk Densities in the Solar System.- 14.7.1. Density as a Function of Potential Energy.- 14.7.2. Chemical Meaning of Bulk Densities.- 14.7.3. Density as Influenced by Solar Radiation.- 14.7.4. Theoretical Implications of Bulk Densities in the Solar System.- 15. Meteorites and Their Precursor States.- 15.1. Interpretation of Meteorite Data.- 15.2. Jet Streams as Meteorite Factories.- 15.3. Characteristics of the Compositional Information from Meteorites, Meteoroids and Comets.- 15.4. Upper Size Limits to Meteorite Predecessor Bodies.- 15.5. Predecessor States of Meteorite Parent Bodies.- 15.6. Properties of Jet Streams Inferred from Meteorite Data.- 15.7. Cohesion Forces in Accreting Embryos and the Record of Mobile Particles and Aggregates in Meteorites.- 15.7.1. Cohesion by Electrostatic Bonding and Vapor Deposition.- 15.7.2. Cohesion Due to Magnetic Forces.- 15.7.3. Data from Meteorites.- 15.7.3.1. Particle Track Records in Meteorites.- 15.7.3.2. Conclusions from Particle Track Data.- 15.8. Evolutionary Sequence of Predecessor States of Meteorites.- 15.9. Age Relationships in the Evolution of Meteorite Parent Jet Streams (Asteroidal and Cometary Streams).- 15.9.1. Closure of Chemical Reservoirs with Regard to Gain or Loss of Elements, Unperturbed by Subsequent Heating Events.- 15.9.2. Crystallization Ages.- 15.9.3. Gas Retention Ages.- 15.9.4. Degassing Ages.- 15.9.5. Cosmic Ray Exposure Ages.- 15.10. Concluding Remarks.- 16. Mass Distribution and the Critical Velocity.- 16.1. Mass Distribution in the Solar System.- 16.1.1. Inadequacy of the Homogeneous Disc Theory.- 16.1.2. Origin and Emplacement of Mass.- 16.1.3. Infall of Matter.- 16.2. The Bands of Secondary Bodies as a Function of Gravitational Potential Energy.- 16.3. Comparative Study of the Groups of Secondary Bodies.- 16.4. Theoretical Background for the Band Formation.- 16.5. Attempts to Interpret the Band Structure.- 16.6. Three Objections.- 16.7. Search for a ‘Critical’ Velocity.- 16.8. Experiments on Critical Velocity.- 16.8.1. Homopolar Experiments.- 16.8.2. Plasma Beam Hitting Neutral Gas Cloud.- 16.8.3. Other Experiments.- 16.8.4. Conclusions.- 16.8.5. Possible Space Experiments.- 16.9. Theory of the Critical Velocity.- 16.10. Conclusions About the Critical Velocity.- 16.11. Chemical Composition of Infalling Gas.- 16.11.1. The Basic Model.- 16.11.2. The A, B, C and D Clouds in the Solar System.- 16.11.3. Refinement of the Basic Model.- 16.11.4. Effect of Interstellar Molecules.- 16.12. The Chemical Composition of the Solar System and Inhomogeneous Plasma Emplacement.- 16.12.1. A Model of Band Formation.- 16.12.2. Conclusions About the Chemical Composition of Celestial Bodies.- 16.13. Modification of Critical Velocity Ionization Distance Due to Interaction with a Partially Corotating Plasma.- 17. The Structure of the Groups.- 17.1 Ionization During the Emplacement of Plasma.- 17.2. Complete Ionization.- 17.3. Partial Ionization.- 17.4. Change of Spin at the Formation of Secondary Bodies.- 17.5. Observational Values of ?ion/T.- 17.6. Mass Distribution as a Function of ?ion/T.- 17.7. Discussion of the Structure of the Groups.- 17.8. Complete List of ?ion/T for All Bodies.- 17.9. Completeness.- 17.9.1. Note on the Inner Limit of a Satellite System.- 17.9.2. Tilt of the Bands in the Gravitational Potential Energy Diagram.- 17.10. Conclusions About the Model of Plasma Emplacement.- References.- Summary and Conclusions.- Index of Subjects.