The Solar System 2

Therese Encrenaz is an Astronomer Emeritus at CNRS and the Paris Observatory, France, specializing in planetary atmospheres. She has directed the Observatory’s Space Research Department. James Lequeux is an honorary astronomer at the Paris Observatory, France. He has directed the Nançay Radio Observatory and the Marseille Observatory; he was also editor-in-chief of the Astronomy & Astrophysics journal.

Preface xi

Thérèse Encrenaz and James Lequeux

Chapter 1 Satellites and Rings of the Giant Planets 1

Athena Coustenis, Marcello Fulchignoni and Françoise Roques

1.1 Introduction 1

1.2 Jupiter’s satellites 5

1.2.1 The Galilean satellites 5

1.2.2 The minor Jovian satellites 17

1.3 Saturn’s satellites 17

1.3.1 Titan 19

1.3.2 Enceladus 30

1.3.3 The other icy satellites 33

1.3.4 Challenges for future missions in the Saturn system and Dragonfly 39

1.4 The satellites of Uranus and Neptune 40

1.4.1 The satellites of Uranus 40

1.4.2 The satellites of Neptune 42

1.4.3 Future exploration of the icy giant planets’ systems 43

1.5 The rings 43

1.5.1 Tidal forces and the Roche limit 46

1.5.2 Flattening and ring dispersion 47

1.5.3 Jupiter’s rings 47

1.5.4 Saturn’s rings 48

1.5.5 Uranus’s rings 51

1.5.6 Neptune’s rings 51

1.5.7 The rings of small bodies 53

1.5.8 Ring dynamics 56

1.5.9 The origin of the rings 59

1.5.10 An exo-ring 61

1.6 References 62

Chapter 2 Comets, Asteroids, and Dwarf Planets 65

Jacques Crovisier and Marcello Fulchignoni

2.1 Comets 65

2.1.1 Definition and nomenclature 66

2.1.2 The orbits and families of the comets 71

2.1.3 Cometary magnitude 74

2.1.4 Space exploration of the comets 76

2.1.5 The nucleus 82

2.1.6 The atmosphere 84

2.1.7 Dust and the tail 102

2.1.8 The chemical diversity of the comets: a relationship to their origins? 109

2.1.9 The interaction of comets with solar wind 110

2.2 The “historical” asteroids 112

2.2.1 The asteroids in the main belt 114

2.2.2 The asteroids that cross the orbit of the terrestrial planets 117

2.2.3 The Trojan asteroids 119

2.2.4 The properties of asteroids 120

2.3 The “new” asteroids 129

2.3.1 The Centaurs 130

2.3.2 Trans-Neptunian objects 131

2.3.3 Interstellar objects 136

2.3.4 The origin and evolution of the asteroids 137

2.4 The dwarf planets 139

2.4.1 Ceres 140

2.4.2 Pluto and its satellites 144

2.4.3 Eris, Haumea, and Makemake 149

2.5 References 152

Chapter 3 Meteorites and Cosmochemistry 157

Brigitte Zanda

3.1 Rocks falling from the sky 157

3.2 Origin of meteorites 162

3.3 Planetary differentiation and groups of meteorites 165

3.4 Chondrites and the origin of the Solar System 169

3.4.1 The chemical composition of chondrites 170

3.4.2 The mineralogy of chondrites 173

3.4.3 The isotopic characteristics of bulk meteorites 180

3.5 Differentiated meteorites 184

3.5.1 Fragments of the asteroid Vesta 184

3.5.2 Iron meteorites 187

3.5.3 Pallasites 190

3.5.4 Fragments of the planet Mars 191

3.6 Witnesses to the formation and evolution of the Solar System 195

3.7 References 197

Chapter 4 Formation and Dynamic History of the Solar System 205

Françoise Roques

4.1 Introduction 205

4.2 Laws of motion of the planets and satellites 207

4.2.1 Kepler’s laws 207

4.2.2 Gravity 209

4.2.3 Newton’s fundamental laws of dynamics 209

4.2.4 The orbital elements 211

4.3 The two-body problem 212

4.4 The three-body problem 213

4.4.1 Jacobi constant and Lagrange points 214

4.4.2 Tadpole and horseshoe orbits 215

4.4.3 Hill sphere 216

4.5 Perturbations and resonances 217

4.6 Stability and chaos in the Solar System 218

4.7 Orbits in relation to a flattened body 220

4.8 Tidal effect 223

4.8.1 Tidal deformation 224

4.8.2 Tidal torque 225

4.8.3 Roche limit 226

4.9 Nongravitational forces and orbits of small bodies 227

4.9.1 Radiation pressure (micrometer-sized grains) 227

4.9.2 Poynting-Robertson effect (small macroscopic particles) 229

4.9.3 The Yarkovsky Effect (meter to kilometer-sized particles) 230

4.9.4 Yorp torque (asymmetric bodies) 230

4.9.5 Friction from solar particles (submicrometer dust) 230

4.9.6 Friction in gas 230

4.10 Formation of planetary systems 231

4.10.1 A disk of planetoids 233

4.10.2 Formation of terrestrial planets 233

4.10.3 Formation of Jupiter 235

4.10.4 Formation of giant planets by core accretion 237

4.10.5 Formation by disk instability 239

4.10.6 Disappearance of the gas 240

4.10.7 Catastrophic collisions 243

4.10.8 Small bodies 245

4.10.9 Planetary migration 246

4.10.10 Fate of the small bodies 249

4.10.11 Exoplanetary formation 252

4.11 References 255

Chapter 5 Origin of Life and Extraterrestrial Life 257

James Lequeux

5.1 Definition of life 257

5.2 The appearance of life on Earth 258

5.2.1 Physicochemical conditions 258

5.2.2 The first forms of life 260

5.2.3 The formation of living cells 265

5.3 Life elsewhere in the Solar System 268

5.3.1 Mars 269

5.3.2 Venus 270

5.3.3 Satellites of the giant planets 271

5.4 How can life be detected on exoplanets? 274

5.5 Communicating with other civilizations? 275

5.6 References 275

Chapter 6 Methods for Studying the Solar System 277

Thérèse Encrenaz, Marcello Fulchignoni, Laurent Lamy, Françoise Roques and James Lequeux

6.1 History 277

6.2 Observational techniques 280

6.2.1 Remote sensing 280

6.2.2 Methods of space exploration 291

6.2.3 Virtual Observatory and databases 303

6.2.4 Perspectives of ground-based and space observations 306

6.3 Computer simulations 314

6.3.1 Dynamics 314

6.3.2 Global climate models 319

6.4 References 324

Appendix Web links 327

Glossary 329

List of Authors 341

Index 343