Wandering Stars : About Planets and Exo-Planets, an Introductory Notebook

by Cole, George H. A.

• ISBN13: 9781860944765
• ISBN10: 1860944760
• Format: Paperback
• Copyright: 2006-04-30
• Publisher: World Scientific Pub Co Inc

Summary

The space vehicle spectaculars of recent years have been revealing the full scope and beauty of our own solar system but have also shown that a growing number of other stars too have planetary bodies orbiting around them. The study of these systems is just beginning. It seems that our galaxy contains untold numbers of planets, and presumably other galaxies will be similar to our own. Our solar system contains life, on Earth: do others as well? Such questions excite modern planetary scientists and astro-biologists. This situation is a far cry from ancient times when the five planets that can be seen from Earth without a telescope were called the "wandering stars." This notebook-cum-workbook provides an introduction to those profound and still-developing modern studies. Written by an expert in the field, it is pitched at a level suitable for beginning students. It is designed particularly for self-study but can also provide background support for students attending lecture courses or teachers developing such courses. The reader is encouraged to add to the arguments of the book as the subject develops. A special feature here is a substantial glossary of terms and people which serves as a starting point for further entries. "Wandering Stars is a key to unlock the door to an exciting and fascinating universe which is still the object of active discovery.

Table of Contents

Preface	v
Part I. Observations Reveal Gravity
1. Early Observations	3	(19)
1.1 Stars and Planets	3	(3)
1.2 Interpretations of the Observations	6	(3)
1.3 Sun, Moon and Earth	9	(3)
1.4 The Shapes of the Orbits	12	(3)
1.5 Kepler's Laws of Planetary Motion	15	(1)
1.6 Galileo's Law of Inertia: Newton's Laws of Motion	16	(2)
1.7 Newton's Law of Gravitation	18	(1)
1.8 A Passing Encounter without Capture	19	(3)
2. A Planet and a Sun: The Role of Gravity	22	(13)
2.1 Specification of an Elliptic Orbit	22	(2)
2.2 Equal Areas in Equal Times	24	(1)
2.3 Consequences of an Elliptical Path: The Inverse Square Force Law	25	(3)
2.4 The Semi-Major Axis and the Period of the Orbit: The 3rd Law	28	(1)
2.5 Two Immediate Consequences	29	(1)
2.6 The Energy in an Elliptic Orbit	30	(1)
2.7 Specifying the Orbit from Observations	31	(1)
2.8 The Different Possible Orbits	32	(3)
3. Several Planets: The Centre of Mass	35	(16)
3.1 More Than One Planet	35	(3)
3.2 Jupiter, Mars and the Asteroids	38	(1)
3.3 The Centre of Mass: Two Masses	39	(3)
3.4 Transfer Orbits	42	(3)
3.5 Tidal Forces	45	(3)
3.6 The Roche Limit	48	(3)
4. The General Structure of a Planet	51	(14)
4.1 Several Energies	51	(3)
4.2 Packing Atoms Together	54	(3)
4.3 The Mass-Radius Relation	57	(1)
4.4 Maximum Size and Mass	58	(1)
4.5 Defining a Planetary Body	59	(2)
4.6 Cosmic Bodies	61	(2)
4.7 Planets and Satellites: Planetary Bodies	63	(2)
5. Fluid Flows and Magnetism	65	(20)
5.1 The Fluid State	65	(3)
5.2 The Importance of Time Scales	68	(1)
5.3 Specifying Fluid Behaviour	69	(1)
5.4 Isothermal Insulating Fluids	70	(3)
5.5 Thermal Insulating Fluid Flows	73	(3)
5.6 Natural Convection: Volcanic Activities	76	(1)
5.7 Boundary Conditions	77	(2)
5.8 Electrically Conducting Fluids	79	(2)
5.9 Application to Planetary Magnetic Fields	81	(4)
Part II. General Features of the Solar System
6. The Larger Members of the Solar System	85	(13)
6.1 The Sun	85	(1)
6.2 The Planets	85	(5)
6.3 Satellites	90	(3)
6.4 Planetary Rings	93	(2)
6.5 Angular Momentum	95	(1)
6.6 Magnetism and Rotation	96	(2)
7. Smaller Members: Asteroids, Comets and Meteorites	98	(12)
7.1 Asteroids	98	(5)
7.2 Comets and Meteor Showers	103	(3)
7.3 Meteorites	106	(1)
7.4 The Edgeworth-Kuiper Belt	106	(1)
7.5 The Oort Cloud	107	(3)
8. The Material of the Solar System	110	(12)
8.1 The Solar/Cosmic Abundance of the Elements	110	(1)
8.2 The Formation of Molecules	111	(2)
8.3 The Compositions of Terrestrial Materials	113	(3)
8.4 The Moon	116	(2)
8.5 Venus	118	(1)
8.6 The Material of the Solar System	118	(2)
8.7 Material in Orbit	120	(2)
9. Finding the Ages of Rocks: Geochronology	122	(13)
9.1 Atoms and Radioactive Decay	122	(1)
9.1.1 Some comments on atomic structure	122	(4)
9.1.2 Atomic transformations: Isotopes	123	(1)
9.1.3 Radioactive series	124	(1)
9.1.4 Single radioactive decay	125	(1)
9.1.5 A radioactive chain	126	(1)
9.2 Nuclear Reactions	126	(2)
9.3 An Elementary Method for Dating Rocks	128	(1)
9.4 The Closure Temperature	129	(1)
9.5 Selecting a Particular Decay Mode	129	(3)
9.5.1 The rubidium–strontium method	129	(1)
9.5.2 Other decay schemes	130	(2)
9.6 Dating Using Nuclear Reactors	132	(3)
10. Surfaces and Interiors	135	(18)
10.1 The Surface Figure	135	(4)
10.1.1 The shape of a planet	136	(2)
10.1.2 Radar studies	138	(1)
10.2 The Interior	139	(7)
10.2.1 Density with depth	139	(2)
10.2.2 The isothermal bulk modulus: Seismology	141	(2)
10.2.3 Travel times	143	(1)
10.2.4 The quality factor, Q	144	(1)
10.2.5 Seismic tomography	145	(1)
10.2.6 Rotation included	145	(1)
10.3 The Near-Surface Interior Region	146	(1)
10.3.1 Surface waves	146	(1)
10.4 Free Body Oscillations	147	(2)
10.5 Empirical Equations of State	149	(1)
10.6 Fluid Bodies	150	(3)
11. The Solid Earth	153	(20)
11.1 General Parameters	154	(2)
11.2 The Interior Seismic Structure	156	(3)
11.2.1 Seismic tomography	158	(1)
11.3 An Active Structure	159	(4)
11.3.1 Mantle material	160	(1)
11.3.2 Mid-ocean ridges and ocean trenches	160	(3)
11.4 Plates and Plate Tectonics	163	(1)
11.5 The Inner and Outer Cores	164	(1)
11.6 A Dynamic Earth	165	(3)
11.7 Comments on the Atmosphere	168	(5)
12. 'Flu' Planets: Mercury and Mars	173	(19)
12.1 Rotation and Temperature	173	(1)
12.2 Surface Details	174	(4)
12.3 Internal Structure of Mercury	178	(1)
12.4 The Mercury Atmosphere	178	(3)
12.5 The General Topology of Mars	181	(1)
12.6 Martian Geology	182	(3)
12.7 Thermal Mars	185	(1)
12.8 The Internal Structure of Mars	186	(2)
12.9 The Atmosphere of Mars	188	(1)
12.10 A Tentative History of Mars	189	(3)
13. Planet Venus	192	(12)
13.1 First Views of the Surface	193	(2)
13.2 Surface Details	195	(4)
13.3 The Venus Interior	199	(1)
13.4 Venus Atmosphere	200	(4)
13.4.1 Composition	200	(1)
13.4.2 Temperature profile	200	(1)
13.4.3 Structure	201	(3)
14. The Planets: Jupiter and Saturn	204	(15)
14.1 Surface Features	206	(3)
14.2 The Heat Budgets	209	(1)
14.3 Visible Surface Compositions	210	(1)
14.4 General Comments on Internal Conditions	211	(2)
14.5 Detailed Model Interiors	213	(1)
14.5.1 Jupiter model interior	213	(1)
14.5.2 Saturn model interior	214	(1)
14.6 Comment on Interior Heat Flow	214	(1)
14.7 Intrinsic Magnetic Fields	215	(4)
15. The Planets: Uranus and Neptune	219	(9)
15.1 Surface Features	221	(1)
15.2 Heat Budgets	222	(2)
15.3 Visible Surface Compositions	224	(1)
15.4 Internal Structure and Conditions	224	(1)
15.5 Comment on Interior Heat Flow	225	(1)
15.6 Intrinsic Magnetism	226	(2)
16. Satellites of the Solar System	228	(29)
16.1 The Moon	228	(8)
16.1.1 Some historical background	228	(2)
16.1.2 Bulk properties	230	(1)
16.1.3 Surface composition: The lava flows	231	(1)
16.1.4 Surface composition: The highland rocks	232	(1)
16.1.5 Surface composition: The lunar "soil"	233	(1)
16.1.6 The interior	233	(3)
16.1.7 Lunar magnetism	236	(1)
16.1.8 Transient lunar events	236	(1)
16.2 The Satellites of Mars	236	(2)
16.3 The Larger Satellites	238	(13)
16.3.1 Io	240	(3)
16.3.2 Europa	243	(2)
16.3.3 Ganymede and Callisto	245	(2)
16.3.4 Titan	247	(4)
16.3.5 Triton	251	(1)
16.4 The Smaller Satellites	251	(1)
16.5 Internal Conditions: Internal Differentiation	251	(6)
Part III. Magnetism within the Solar System
17. Intrinsic Magnetism of the Earth	257	(16)
17.1 The Magnetic Poles	257	(2)
17.2 The Magnetic Elements	259	(2)
17.3 Separation into a Dipole and Non-dipole Fields	261	(4)
17.4 Short Time Variations: The Secular Variation	265	(1)
17.5 Long Time Variations: Magnetic Field Reversals	265	(3)
17.6 The Geomagnetic Poles have Moved: Continental Drift	268	(3)
17.7 Creation of Ocean Floor	271	(2)
18. The Earth's External Magnetism	273	(11)
18.1 The Effects of the Solar Emissions	273	(4)
18.2 The Interplanetary Magnetic Field	277	(1)
18.3 The Polar Aurorae	278	(1)
18.4 Magnetic Storms and Transient Disturbances	279	(1)
18.5 The Special Effect of the Moon	280	(1)
18.6 van Allen Radiation Belts	281	(3)
19. The Magnetism of the Other Planets	284	(15)
19.1 The Intrinsic Magnetic Fields	284	(2)
19.2 The Magnetospheres	286	(6)
19.3 Other Examples for Planetary Bodies	292	(2)
19.4 Mot ion through the Interstellar Medium	294	(1)
19.5 Companions to Other Stars	294	(5)
Part IV. Stars as a Continuing Source of Energy
20. Evolution of Stars	299	(13)
20.1 Observations and Measurements	299	(2)
20.2 Galaxies and Stars	301	(1)
20.3 The Life Expectancy of a Star	302	(2)
20.4 The Hertztsprung-Russell Diagram	304	(8)
21. The Constitution of Stars	312	(12)
21.1 A Family of Similar Stars: The Assumptions	312	(2)
21.2 Specifying the Family of Stars	314	(1)
21.3 Some Immediate Conclusions	315	(1)
21.4 The Luminosity: The Mass-Radius Relation	316	(1)
21.5 The Mass and Luminosity Relation	317	(1)
21.6 The Central Temperature	317	(1)
21.7 The Life Expectancy: Dependence on the Mass	318	(1)
21.8 The State of Dense Matter	318	(6)
21.8.1 Non-relativistic case	320	(1)
21.8.2 Relativistic case	321	(3)
22. Stellar Energy Source	324	(11)
22.1 Isotopes	324	(1)
22.2 The Binding Energy: Fusion and Fission	325	(2)
22.3 Energy from Fusion	327	(1)
22.4 The Hydrogen-Helium Process	328	(2)
22.4.1 The proton-proton chain	328	(1)
22.4.2 The carbon-nitrogen cycle	329	(1)
22.5 Reactions at Higher Temperatures	330	(1)
22.6 The Escape of Radiation from a Star	331	(1)
22.7 Synthesizing the Heavier Elements: r- and s- processes	332	(3)
23. The Sun and Its Interior	335	(13)
23.1 Internal Conditions	336	(3)
23.2 The Surface: The Photosphere	339	(6)
23.3 Solar Rotation	345	(3)
24. Solar Emissions of Particles: The Solar Wind	348	(13)
24.1 Above the Surface: The Chromosphere and Corona	349	(4)
24.2 Magnetism	353	(2)
24.3 The Solar Wind	355	(2)
24.4 Present and Future Variability	357	(4)
Part V. Exoplanets
25. A Planetary System from Afar: The Solar System	361	(10)
25.1 Observing the Motion of the Central Star	361	(5)
25.2 The Case of a Transit	366	(2)
25.3 Polarimetry	368	(1)
25.4 Nulling Interferometry	368	(1)
25.5 Astrometry	369	(1)
25.6 Direct Imaging - White Dwarf Stars	369	(1)
25.7 Conclusion	369	(2)
26. Observed Exo-Planet Systems	371	(10)
26.1 Pulser Systems	371	(1)
26.2 A Companion to a Solar-Type Star	372	(1)
26.3 Stellar Transits	373	(1)
26.4 A Survey of the Measurements	374	(3)
26.5 Multiple Companion Systems	377	(1)
26.6 Small Eccentricities	378	(1)
26.7 Systems with a Large Semi-Major Axis	378	(2)
26.8 Small Eccentricity and Larger Semi-major Axis	380	(1)
27. Assessing the Observational Data	381	(8)
27.1 Firm Characteristics	381	(1)
27.2 More Massive Companions	382	(1)
27.3 A Special Case: Transit Systems	383	(1)
27.4 Small Semi-Major Axes: Role of Eccentricity	384	(1)
27.5 The Future?	385	(4)
Part VI. Exo-Biology
28. Life on Earth	389	(13)
28.1 Early Life	389	(2)
28.2 The Characteristics of Early Life	391	(2)
28.3 Oxygen in the Atmosphere	393	(1)
28.4 The Evolutionary Sequence	394	(2)
28.5 The Movement of Continents	396	(1)
28.6 Life on the Atlantic mid-Ocean Ridge	397	(1)
28.7 Changes of Climate	398	(1)
28.8 Some Final Comments	399	(3)
29. What Makes a Planet Habitable?	402	(10)
29.1 An Overall Requirement	402	(1)
29.2 Atomic Constraints: Binding Energies	403	(2)
29.3 Stellar Radiation	405	(1)
29.4 Heat from the Central Star	405	(1)
29.5 The Role of an Atmosphere: Planetary Mass	406	(2)
29.6 The Role of Water	408	(1)
29.7 Surface Features: Body Size and Scaling	409	(3)
30. An Anthropic Universe?	412	(13)
30.1 Describing the Physical World	412	(2)
30.2 Consequences of the Strength of the Forces of Nature	414	(1)
30.3 The Beginnings	415	(3)
30.4 The Size of Our Universe	418	(1)
30.5 Model Universes: Anthropic Principles	419	(2)
30.6 Information and the Universe	421	(1)
30.7 Extra-terrestrial Visitations	422	(3)
Epilogue	425	(6)
Some Historic Events in the Space Probe Exploration of the Solar System	431	(2)
Some Useful References	433	(2)
Glossary	435	(40)
Problems and Solutions	475	(10)
Index	485