Book contents
- Frontmatter
- Contents
- Preface to the First Edition
- Preface to the Second Edition
- Acknowledgments
- Prologue
- Chapter 1 A brief history
- Chapter 2 The universe
- Chapter 3 Stars
- Chapter 4 The solar nebula
- Chapter 5 Composition and chemical evolution of the solar nebula
- Chapter 6 The evidence from meteorites
- Chapter 7 Building planets
- Chapter 8 The giant planets
- Chapter 9 Satellites and rings
- Chapter 10 The refugees
- Chapter 11 The survivors: Mercury and Mars
- Chapter 12 The twins: Venus and the Earth
- Chapter 13 The Moon
- Chapter 14 The role of impacts
- Chapter 15 Epilogue: on the difficulty of making Earth-like planets
- Name index
- Subject index
Chapter 4 - The solar nebula
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface to the First Edition
- Preface to the Second Edition
- Acknowledgments
- Prologue
- Chapter 1 A brief history
- Chapter 2 The universe
- Chapter 3 Stars
- Chapter 4 The solar nebula
- Chapter 5 Composition and chemical evolution of the solar nebula
- Chapter 6 The evidence from meteorites
- Chapter 7 Building planets
- Chapter 8 The giant planets
- Chapter 9 Satellites and rings
- Chapter 10 The refugees
- Chapter 11 The survivors: Mercury and Mars
- Chapter 12 The twins: Venus and the Earth
- Chapter 13 The Moon
- Chapter 14 The role of impacts
- Chapter 15 Epilogue: on the difficulty of making Earth-like planets
- Name index
- Subject index
Summary
The initial concept
The fundamental and perhaps the most obvious fact about the solar system is that the planets and satellites mostly lie close to the plane of the ecliptic (the Sun–Earth plane) and, with minor and informative exceptions, rotate in the same sense, both around the Sun and about their axes of rotation. Their orbits, although elliptical, have very low eccentricities. In the 18th century, scientists were unaware of the retrograde rotation of Venus and of other irregularities: what they saw appeared to be as well ordered as a clock. This fortunate lack of too much information enabled the French astronomer and mathematician, Pierre-Simon, marquis de Laplace, to propose in 1796 that the solar system originated from a rotating disk of dust and gas [1]. He called this disk the solar nebula. In his model, the planets condensed successively from rings as the nebula contracted. This elegant concept survived in its original form until late in the 19th century. The crucial and ultimately fatal flaw of the original laplacian theory was the failure to account for the concentration of (i) angular momentum in the planets and of (ii) mass in the Sun [2].
The view that the Sun and the planets formed from a rotating disk of gas and dust, the solar nebula, provides such an obvious explanation that it has become axiomatic. Nevertheless, it is wise to question established viewpoints.
- Type
- Chapter
- Information
- Solar System EvolutionA New Perspective, pp. 47 - 72Publisher: Cambridge University PressPrint publication year: 2001