ASTRONOMY. Eric Chaisson. Steve McMillan. A Beginner's Guide to the Universe FOURTH EDITION. Tufts University. Drexel University

Transcription

1 ASTRONOMY A Beginner's Guide to the Universe FOURTH EDITION Eric Chaisson Tufts University Steve McMillan Drexel University PEARSON Prentice Hall Pearson Education, Inc. Upper Saddle River, New Jersey 07458

2 CONTENTS Preface xvii SA FOUNDATIONS PROLOGUE Charting the Heavens 2 P.I The "Obvious" View 4 P.2 Earth's Orbital Motion 7 Physlet Illustration Solar vs Sidereal Day 7 Animation The Earth's Seasons 8 P. 3 The Measurement of Distance 10 More Precisely P-l Angular Measure 10 Tutorial Stellar Parallax 12 More Precisely P-2 Measuring Distances with Geometry 13 Physlet Illustration Angular Measurements vs Distance Measurements 13 Discovery P-l Sizing up Planet Earth 14 Chapter Review 14 1 THE COPERNICAN REVOLUTION The Birth of Modern Science The Orbit of the Moon 18 Physlet Illustration Lunar Phases 19 Physlet Illustration Eclipses The Motions of the Planets 22 Discovery 1-1 The Scientific Method The Birth of Modern Astronomy The Laws of Planetary Motion 30 More Precisely 1-1 Some Properties of Planetary Orbits 32 Physlet Illustration Kepler's 3 Laws Newton's Laws 34 Physlet Illustration Universal Gravitation 36 More Precisely 1-2 Weighing the Sun 37 Chapter Review 39

3 LIGHT AND MATTER The Inner Workings of the Cosmos 42 a, 2.1 Information from the Skies 44 Physlet Illustration Basic Wave Properties Waves in What? 46 Physlet Illustration Electromagnetic Waves The Electromagnetic Spectrum Thermal Radiation 51 More Precisely 2-1 The Kelvin Temperature Scale 51 Animation The Planck Spectrum 53 More Precisely 2-2 More on the Radiation Laws Spectroscopy The Formation of Spectral Lines 59 Animation Classical Hydrogen Atom I 61 Animation Classical Hydrogen Atom II 61 Physlet Illustration Bohr Atom and Spectra The Doppler Effect 64 Physlet Illustration Doppler Effect 66 Tutorial Doppler Effect 66 Chapter Review 67 3 TELESCOPES The Tools of Astronomy Optical Telescopes 72 Physlet Illustration Image Formation by Lens 73 Tutorial The Optics of a Simple Lens 73 Tutorial Chromatic Aberration 73 Tutorial Mirrors in Telescopes 73 Physlet Illustration Image Formation by Mirror 73 Physlet Illustration Telescope Designs Telescope Size High-Resolution Astronomy Radio Astronomy 82 Discovery 3-1 The Hubble Space Telescope Other Astronomies 88 Animations Light and Data Path 91 Chapter Review 94

4 OUR PLANETARY SYSTEM 4 THE SOLAR SYSTEM Interplanetary Matter and the Birth of the Planets An Inventory of the Solar System 100 Animation An Astronomical Ruler 100 Animation Size and Scale of the Terrestrial Planets 101 Animation The Gas Giants 101 Physlet Illustration Mass of Planet from Kepler's 3 rd Law Solar System Debris 104 a Discovery 4-1 What Killed the Dinosaurs? 106 Animation Comet Hale-Bopp 108 Animation Anatomy of a Comet Part I 109 Animation Anatomy of a Comet Part II 110 Animation Asteroid Comet Breakup The Formation of the Solar System 114 Animation Beta Pictoris Warp 117 a More Precisely 4-1 Conservation of Angular Momentum 118 Physlet Illustration Conservation of Angular Momentum 118 Animation Solar System Formation Planets Beyond the Solar System 124 Chapter Review EARTH AND ITS MOON Our Cosmic Backyard Earth and the Moon in Bulk The Tides 133 a More Precisely 5-1 Why Air Sticks Around Atmospheres 136 Tutorial Atmospheric Lifetimes 137 Discovery 5-1 Earth's Growing Ozone Hole 138 Physlet Illustration Escape Speed 139 Tutorial Greenhouse Effect 139 H Discovery 5-2 The Greenhouse Effect and Global Warming Interiors Surface Activity on Earth 144

5 5.6 The Surface of the Moon Magnetospheres 150 Physlet Illustration Magnetic Field of Planet v History of the Earth-Moon System 153 Chapter Review 155 O THE TERRESTRIAL PLANETS A Study in Contrasts Orbital and Physical Properties Rotation Rates 161 Physlet Illustration Rotation of Mercury 162 Animation The Phases of Venus Atmospheres 163 Animation The Rotation of Venus The Surface of Mercury 165 Physlet Illustration Meteor Energy The Surface of Venus The Surface of Mars 170 """ Video Mars North Pole 171 Video Rotation of Mars 171 Discovery 6-1 Martian Canals? 172 Discovery 6-2 Life on Mars? Internal Structure and Geological History 180 Animation Terrestrial Planets Atmospheric Evolution on Earth, Venus, and Mars 182 Tutorial Greenhouse Effect The Moons of Mars 184 Chapter Review THE JOVIAN PLANETS Giants of the Solar System Observations of Jupiter and Saturn 190 Animation Galileo Mission to Jupiter 190 More Precisely 7-1 Gravitational "Slingshots" 191 Physlet Illustration Gravitational Slingshot The Discoveries of Uranus and Neptune Bulk Properties of the Jovian Planets Jupiter's Atmosphere The Atmospheres of the Outer Jovian Worlds 198 Video Saturn Storm 200

6 7.6 Jovian Interiors 203 Animation The Gas Giants Part II 204 Discovery 7-1 A Cqmetary Impact 207 Chapter Review MOONS, RINGS, AND PLUTO Small Worlds Among Giants The Galilean Moons of Jupiter 212 Animation Io Cutaway 215 Animation Galileo Flyby of Io 215 Video Jupiter's Moon Europa 216, Video Jupiter's Moon Ganymede The Large Moons of Saturn and Neptune The Medium-Sized Jovian Moons Planetary Rings 223 Physlet Illustration Tidal Forces vs. Self-Gravity Pluto and Its Moon 229 Animation Orbits of Neptune and Pluto 230 Video Historical Observations of Pluto 230 Animation Mutual Eclipses of Charon and Pluto Is Pluto a Planet? 232 Chapter Review 234 THE STARS 9 THE SUN Our Parent Star The Sun in Bulk 240 Tutorial SuperSpaceship Voyage to the Sun The Solar Interior 242 Discovery 9-1 SOHO: Eavesdropping on the Sun 244 Physlet Illustration Random Walk The Solar Atmosphere The Active Sun 249 Physlet Illustration Rotation by Sunspots 250 Video May Solar Flare Event 254 Animation Coronal Mass Ejection The Heart of the Sun 255 More Precisely 9-1 The Strong and Weak Nuclear Forces 259 Chapter Review 259

7 10 MEASURING THE STARS Giants, Dwarfs, and the Main Sequence The Solar Neighborhood Luminosity and Apparent Brightness 267 Discovery 10-1 Naming the Stars 267 Animation The Inverse-square Law 268 More Precisely 10-1 More on the Magnitude Scale Stellar Temperatures 270 Physlet Illustration Blackbody and Stellar Temperature Stellar Sizes 273 More Precisely 10-2 Estimating Stellar Radii The Hertzsprung-Russell Diagram 275 Tutorial Hertzsprung-Russell Diagram Extending the Cosmic Distance Scale Stellar Masses 279 Tutorial Binary Stars-Radial Velocity Curves 279 Tutorial Eclipsing Binary Stars-Light Curves 280 Chapter Review THE INTERSTELLAR MEDIUM Star Formation in the Milky Way Interstellar Matter Interstellar Clouds 290 Discovery 11-1 Ultraviolet Astronomy and the "Local Bubble" 292 Animation M16 Eagle Nebula 293 Video Gaseous Pillars of Star Birth 293 Physlet Illustration Spin Flip and 21-cm Radiation The Formation of Stars Like the Sun 298 Video Orion Nebula Mosaic 302 Animation Bi-Polar Outflow Stars of Other Masses Star Clusters 307 Chapter Review STELLAR EVOLUTION The Lives and Deaths of Stars Leaving the Main Sequence Evolution of a Sun-like Star 315 Animation Death of a Sun 318 Animation Death of a Sun Part II The Death of a Low-Mass Star 319 Animation Bi-Polar Planetary Nebula 320 (

8 Video Formation of Helix Nebula 320 Animation H-R Diagram Tracks Stellar Evolution 321 Animation Recurrent Nova Evolution of High-Mass Stars Supernova Explosions 326 Physlet Illustration Supernova 326 Animation Supernova Explosion 328 n Discovery 12-1 Supernova 1987A 330 Animation Shockwaves Hit the Ring Around Supernova 1987A 331 Animation Composition and Structure of the Ring Around Supernova 1987A Observing Stellar Evolution in Star Clusters 332 n More Precisely 12-1 The Cycle of Stellar Evolution 335 Animation Evolution of a 1-Solar-Mass Star 335 Chapter Review NEUTRON STARS AND BLACK HOLES Strange States of Matter Neutron Stars Pulsars Neutron-Star Binaries 343 Physlet Illustration Period of Pulsar Gamma-Ray Bursts 346 n Discovery 13-1 Gravity Waves Black Holes 349 a More Precisely 13-1 Einstein's Theories of Relativity 350 Physlet Illustration Equivalence Principle 351 Tutorial SuperSpaceship Gravity and Curved Space 352 More Precisely 13-2 Tests of General Relativity Space Travel Near Black Holes Observational Evidence for Black Holes 357 Animation Black Hole Geometry 358 Chapter Review 360 GALAXIES AND THE UNIVERSE 14 THE MILKY WAY GALAXY A Grand Design Our Parent Galaxy Measuring the Milky Way 367 Animation Cepheid Star in Distant Galaxy 369 a Discovery 14-1 Early Computers 371

9 14.3 Galactic Structure The Formation of the Milky Way Galactic Spiral Arms 376 Discovery 14-2 Density Waves The Mass of the Milky Way Galaxy 380 Physlet Illustration The Mass of a Galaxy The Galactic Center 383 Chapter Review NORMAL AND ACTIVE GALAXIES Building Blocks of the Universe Hubble's Galaxy Classification Clusters of Galaxies 399 Animation Cluster Merger Active Galactic Nuclei 403 Discovery 15-1 Colliding Galaxies 404 Animation Collision of Two Spiral Galaxies 404 Animation Birth of a Quasar The Central Engine of an Active Galaxy 412 Animation Active Galaxy 413 Animation Cosmic Jets 413 Animation Black Hole in Galaxy M Animation Supermassive Black Hole Supermassive Black Holes in Galactic Nuclei 416 Chapter Review HUBBLE'S LAW AND DARK MATTER The Large-Scale Structure of the Cosmos Cosmic Expansion 422 More Precisely 16-1 Relativistic Redshifts and Look-Back Time 424 Physlet Illustration Hubble's Law-Doppler Shift & Distance Dark Matter in the Universe 426 Animation Dark Matter Large-Scale Structure 429 Animation Gravitational Lensing Galaxy Formation and Evolution 434 Video Hubble Deep Field Zoom Sequence 435 Animation Starburst Galaxy 436 Physlet Illustration Active Galactic Nuclei 440 Chapter Review 441

10 17 COSMOLOGY The Big Bang and the Fate of the Universe The Universe on the Largest Scales The Expanding Universe 447 Animation Big Bang The Fate of the Cosmos 450 Discovery 17-1 The Cosmological Constant The Geometry of Space 456 More Precisely 17-1 Curved Space 457 Physlet Illustration Creation and Annihilation and Temperature The Early Universe The Formation of Nuclei and Atoms Cosmic Inflation The Formation of Large-Scale Structure in the Universe 465 Animation Cosmic Structure 465 Chapter Review LIFE IN THE UNIVERSE Are We Alone? Cosmic Evolution Life in the Solar System Intelligent Life in the Galaxy 477 Physlet Illustration Drake Equation and Number of Intelligent Civilizations The Search for Extraterrestrial Intelligence 482 Chapter Review 486 Appendices A-l Appendix 1: Scientific Notation A-l Appendix 2: Astronomical Measurement A-2 Appendix 3: Tables A-3 Glossary G-l Answers to Concept Check Questions AK-1 Answers to Self-Test Questions AK-4 Index 1-1