Barrie W. Jones - Discovering the solar system.pdf.docx

ITETESlarSystemSecond EditionSWILEY

Discovering the Solar SystemSecond Edition

Discovering the Solar SystemSecond EditionBarrie W. Jones The Open University, Milton Keynes, UK

Copyright 2007 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester,West Sussex PO19 8SQ, EnglandTelephone +44 1243 779777Email (for orders and customer service enquiries): cs-books@wiley.co.uk Visit our Home Page on www.wiley.comAll Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP, UK, without the permission in writing of the Publisher. Requests to the Publisher should be addressed to the Permissions Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England, or emailed to permreq@wiley.co.uk, or faxed to (+44) 1243 770620.Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The Publisher is not associated with any product or vendor mentioned in this book.This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the Publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought.Other Wiley Editorial OfficesJohn Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USAJossey-Bass, 989 Market Street, San Francisco, CA 94103-1741, USAWiley-VCH Verlag GmbH, Boschstr. 12, D-69469 Weinheim, GermanyJohn Wiley & Sons Australia Ltd, 33 Park Road, Milton, Queensland 4064, AustraliaJohn Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore 129809John Wiley & Sons Canada Ltd, 6045 Freemont Blvd, Mississauga, Ontario, L5R 4J3, CanadaWiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.Anniversary Logo Design: Richard J. PacificoLibrary of Congress Cataloging in Publication DataJones, Barrie William.Discovering the solar system / Barrie W. Jones. 2nd ed.p. cm. ISBN 978-0-470-01830-9 1. Solar system. I. Title. QB501.J65 2007 523.2dc222007008860British Library Cataloguing in Publication DataA catalogue record for this book is available from the British LibraryISBN 978-0-470-01830-9 (HB) ISBN 978-0-470-01831-6 (PB)Typeset in 10/12pt Times by Integra Software Services Pvt. Ltd, Pondicherry, India Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire This book is printed on acid-free paper responsibly manufactured from sustainable forestry in which at least two trees are planted for each one used for paper production.

To my wife Anne, the rest of my family, and to my friend and colleague Nick Sleep

ContentsList of Tables xiii Preface and Study Guide to the First Edition xiv Preface to the Second Edition xvi1 The Sun and its Family 1 1.1 The Sun 1 1.1.1 The Solar Photosphere 1 1.1.2 The Solar Atmosphere 3 1.1.3 The Solar Interior 5 1.1.4 The Solar Neutrino Problem 8 1.2 The Suns Family A Brief Introduction 9 1.2.1 The Terrestrial Planets and the Asteroids 11 1.2.2 The Giant Planets 11 1.2.3 Pluto and Beyond 13 1.3 Chemical Elements in the Solar System 14 1.4 Orbits of Solar System Bodies 15 1.4.1 Keplers Laws of Planetary Motion 15 1.4.2 Orbital Elements 18 1.4.3 Asteroids and the TitiusBode Rule 20 1.4.4 A Theory of Orbits 20 1.4.5 Orbital Complications 24 1.4.6 Orbital Resonances 27 1.4.7 The Orbit of Mercury 29 1.5 Planetary Rotation 30 1.5.1 Precession of the Rotation Axis 33 1.6 The View from the Earth 35 1.6.1 The Other Planets 35 1.6.2 Solar and Lunar Eclipses 36 1.7 Summary of Chapter 1 402 The Origin of the Solar System 48 2.1 The Observational Basis 48 2.1.1 The Solar System 48 2.1.2 Exoplanetary Systems 49 2.1.3 Star Formation 53 2.1.4 Circumstellar Discs 55 2.2 Solar Nebular Theories 56 2.2.1 Angular Momentum in the Solar System 57 2.2.2 The Evaporation and Condensation of Dust in the Solar Nebula 60 2.2.3 From Dust to Planetesimals 64

viii CONTENTS2.2.4 From Planetesimals to Planets in the Inner Solar System 65 2.2.5 From Planetesimals to Planets in the Outer Solar System 69 2.2.6 The Origin of the Oort Cloud, the EK Belt, and Pluto 73 2.3 Formation of the Satellites and Rings of the Giant Planets 75 2.3.1 Formation of the Satellites of the Giant Planets 75 2.3.2 Formation and Evolution of the Rings of the Giant Planets 76 2.4 Successes and Shortcomings of Solar Nebular Theories 80 2.5 Summary of Chapter 2 813 Small Bodies in the Solar System 83 3.1 Asteroids 83 3.1.1 Asteroid Orbits in the Asteroid Belt 84 3.1.2 Asteroid Orbits Outside the Asteroid Belt 86 3.1.3 Asteroid Sizes 89 3.1.4 Asteroid Shapes and Surface Features 91 3.1.5 Asteroid Masses, Densities, and Overall Composition 93 3.1.6 Asteroid Classes and Surface Composition 94 3.2 Comets and Their Sources 98 3.2.1 The Orbits of Comets 99 3.2.2 The Coma, Hydrogen Cloud, and Tails of a Comet 101 3.2.3 The Cometary Nucleus 103 3.2.4 The Death of Comets 106 3.2.5 The Sources of Comets 107 3.2.6 The Oort Cloud 108 3.2.7 The EK Belt 109 3.3 Meteorites 111 3.3.1 Meteors, Meteorites, and Micrometeorites 112 3.3.2 The Structure and Composition of Meteorites 113 3.3.3 Dating Meteorites 116 3.3.4 The Sources of Meteorites 118 3.3.5 The Sources of Micrometeorites 121 3.4 Summary of Chapter 3 1234 Interiors of Planets and Satellites: The Observational and Theoretical Basis 126 4.1 Gravitational Field Data 126 4.1.1 Mean Density 126 4.1.2 Radial Variations of Density: Gravitational Coefficients 131 4.1.3 Radial Variations of Density: The Polar Moment of Inertia 134 4.1.4 Love Numbers 135 4.1.5 Local Mass Distribution, and Isostasy 135 4.2 Magnetic Field Data 136 4.3 Seismic Wave Data 139 4.3.1 Seismic Waves 139 4.3.2 Planetary Seismic Wave Data 142 4.4 Composition and Properties of Accessible Materials 143 4.4.1 Surface Materials 143 4.4.2 Elements, Compounds, Affinities 144

CONTENTS ix4.4.3 Equations of State, and Phase Diagrams 145 4.5 Energy Sources, Energy Losses, and Interior Temperatures 149 4.5.1 Energy Sources 150 4.5.2 Energy Losses and Transfers 154 4.5.3 Observational Indicators of Interior Temperatures 159 4.5.4 Interior Temperatures 159 4.6 Summary of Chapter 4 1615 Interiors of Planets and Satellites: Models of Individual Bodies 163 5.1 The Terrestrial Planets 163 5.1.1 The Earth 166 5.1.2 Venus 169 5.1.3 Mercury 170 5.1.4 Mars 171 5.2 Planetary Satellites, Pluto, EKOs 173 5.2.1 The Moon 173 5.2.2 Large IcyRocky Bodies: Titan, Triton, Pluto, and EKOs 176 5.2.3 The Galilean Satellites of Jupiter 179 5.2.4 Small Satellites 183 5.3 The Giant Planets 183 5.3.1 Jupiter and Saturn 185 5.3.2 Uranus and Neptune 189 5.4 Magnetospheres 190 5.4.1 An Idealised Magnetosphere 191 5.4.2 Real Magnetospheres 192 5.5 Summary of Chapter 5 1946 Surfaces of Planets and Satellites: Methods and Processes 197 6.1 Some Methods of Investigating Surfaces 197 6.1.1 Surface Mapping in Two and Three Dimensions 197 6.1.2 Analysis of Electromagnetic Radiation Reflected or Emitted by a Surface 200 6.1.3 Sample Analysis 201 6.2 Processes that Produce the Surfaces of Planetary Bodies 201 6.2.1 Differentiation, Melting, Fractional Crystallisation, and Partial Melting 202 6.2.2 Volcanism and Magmatic Processes 204 6.2.3 Tectonic Processes 206 6.2.4 Impact Cratering 207 6.2.5 Craters as Chronometers 212 6.2.6 Gradation 216 6.2.7 Formation of Sedimentary Rocks 219 6.2.8 Formation of Metamorphic Rocks 220 6.3 Summary of Chapter 6 2207 Surfaces of Planets and Satellites: Weakly Active Surfaces 223 7.1 The Moon 223 7.1.1 Impact Basins and Maria 224 7.1.2 The Nature of the Mare Infill 225