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The CosmosAstronomy in the New Millennium
F IFTH EDIT ION
The Fifth Edition of The Cosmos: Astronomy in the New Millennium
provides you with the fundamentals of
astronomical knowledge that have been built up over decades,
with an expanded discussion of the incredible
advances that are now taking place in this fast-paced field,
such as New Horizons’ flyby of Pluto, exoplanets,
“dark matter,” and the direct detection of gravitational waves
by LIGO.
Written in a clear and easily understandable style, this
textbook has been thoroughly revised to include
(among other things) updated data and figures, new images from
recent space missions and telescopes, the
latest discoveries on supernovae, and new observations of the
region around the four-million-solar-mass
black hole at the center of our Milky Way Galaxy.
Jay M. Pasachoff, Field Memorial Professor of Astronomy at
Williams College, teaches the astronomy
survey course. He is also Director of the Hopkins Observatory
there. He received his undergraduate and grad-
uate degrees from Harvard and then had postdoctoral fellowships
at the Harvard College Observatory and
the California Institute of Technology, where he has also had
recent sabbatical leaves. He now has a visiting
appointment at the Carnegie Observatories.
He has observed 70 solar eclipses. He also studies occultations
of stars by Pluto and other objects in the
outer Solar System.
Pasachoff is Chair of the Working Group on Eclipses of the
International Astronomical Union and was
Chair of the American Astronomical Society’s Historical
Astronomy Division. He is also co-editor of Teaching
and Learning Astronomy (2005) and Innovation in Astronomy
Education (2008).
He received the American Astronomical Society’s Education Prize
(2003); the Janssen Prize from the
Société Astronomique de France (2012); and the Richtmyer
Memorial Lecture Award, American Association
of Physics Teachers (2017). Asteroid (5100) Pasachoff is named
after him.
Alex Filippenko is a Professor of Astronomy, and the Richard
& Rhoda Goldman Distinguished Professor
in the Physical Sciences, at the University of California,
Berkeley. He received his undergraduate degree
from the University of California, Santa Barbara (1979) and his
doctorate from the California Institute of
Technology (1984).
His primary areas of research are exploding stars, gamma-ray
bursts, active galaxies, black holes, and obser-
vational cosmology. Filippenko was the only person to have been
a member of both teams that revealed the
Nobel-worthy accelerating expansion of the Universe. He is one
of the world’s most highly cited astronomers
and was elected to the National Academy of Sciences (2009).
Filippenko has won many prestigious teaching awards, including
the Carnegie/CASE National Professor of
the Year among doctoral institutions (2006). He has appeared
frequently on science newscasts and television
documentaries, especially The Universe series. He received the
Carl Sagan Prize for Science Popularization
(2004). He enjoys world travel and observing total solar
eclipses (16, all successfully).
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An artist’s conception of two black holes, GW170104, as they
merged, similar to the ones detected by the Laser Interferometer
Gravitational-wave
Observatory (LIGO).
Credit: LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)
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The CosmosAstronomy in the New Millennium
F IFTH EDIT ION
Jay M. PasachoffWilliams College, Massachusetts
Alex FilippenkoUniversity of California, Berkeley
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It furthers the University’s mission by disseminating knowledge
in the pursuit of
education, learning, and research at the highest international
levels of excellence.
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© Jay M. Pasachoff and Alex Filippenko 2019
This publication is in copyright. Subject to statutory
exception
and to the provisions of relevant collective licensing
agreements,
no reproduction of any part may take place without the
written
permission of Cambridge University Press.
Fourth edition published in 2013. The previous edition (The
Cosmos, 3rd Edition) was
published in 2007 by Brooks/Cole Cengage.
Printed and bound in Great Britain by Clays Ltd, Elcograf
S.p.A.
A catalog record for this publication is available from the
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ISBN 978-1-108-43138-5 Paperback
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v
Contents
Preface xix
1. A Grand Tour of the Heavens 1
2. Light, Matter, and Energy: Powering the Universe 23
3. Light and Telescopes: Extending Our Senses 41
4. Observing the Stars and Planets: Clockwork of the Universe
75
5. Gravitation and Motion: The Early History of Astronomy
107
6. The Terrestrial Planets: Earth, Moon, and Their Relatives
133
7. The Jovian Planets: Windswept Giants 189
8. Pluto, Comets, Asteroids, and Beyond 225
9. Our Solar System and Others 263
10. Our Star: The Sun 289
11. Stars: Distant Suns 317
12. How the Stars Shine: Cosmic Furnaces 357
13. The Death of Stars: Recycling 381
14. Black Holes: The End of Space and Time 415
15. The Milky Way: Our Home in the Universe 447
16. A Universe of Galaxies 479
17. Quasars and Active Galaxies 523
18. Cosmology: The Birth and Life of the Cosmos 553
19. In the Beginning 589
20. Life in the Universe 623
Epilogue 644
Appendix 1/2. Measurement Systems/Basic Constants 645
Appendix 3. Planets and Dwarf Planets 647
Appendix 4. The Brightest Stars 649
Appendix 5. The Nearest Stars 651
Appendix 6. The Messier Catalogue 654
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vi Contents
Appendix 7. The Constellations 656
Appendix 8. Star Names 658
Selected reading 661
Glossary 668
Index 685
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vii
Preface xix
1. A Grand Tour of the Heavens 1 1.1 Peering Through the
Universe: A Time Machine 2
1.2 How Do We Study Things We Can’t Touch? 2
Figure It Out 1.1 Keeping Track of Space and Time 3
Figure It Out 1.2 Scientific Notation 3
1.3 Finding Constellations in the Sky 5
1.3a The Autumn Sky 6
Star Party 1.1 Using the Sky Maps 7
1.3b The Winter Sky 9
1.3c The Spring Sky 10
1.3d The Summer Sky 10
1.4 How Do You Take a Tape Measure to the Stars? 11
A Closer Look 1.1 A Sense of Scale: Measuring
Distances 12
1.5 The Value of Astronomy 14
1.5a The Grandest Laboratory of All 14
1.5b Origins 15
1.6 What Is Science? 16
1.7 Why Is Science Far Better Than Pseudoscience? 17
2. Light, Matter, and Energy: Powering the Universe 23
2.1 Studying a Star Is Like Looking at a Rainbow 24
Figure It Out 2.1 The Nature of Light 24
2.2 “Blackbodies” and Their Radiation 26
Figure It Out 2.2 Blackbody Radiation and Wien’s
Law 26
Figure It Out 2.3 Blackbody Radiation and the
Stefan–Boltzmann Law 27
2.3 What Are Those Missing Colors and Where Are They? 28
2.4 The Story Behind the Bohr Atom 30
2.5 The Doppler Effect and Motion 33
Figure It Out 2.4 Temperature Conversions 35
3. Light and Telescopes: Extending Our Senses 41 3.1 The First
Telescopes for Astronomy 41
3.2 How Do Telescopes Work? 43
3.3 Modern Telescopes 46
3.3a Current Large Telescopes Around the World 46
Figure It Out 3.1 Light-Gathering Power of a
Telescope 47
Figure It Out 3.2 Changing Units 47
3.3b The Next Generation of Optical and Infrared
Ground-Based Telescopes 51
3.4 The Big Picture: Mapping the Sky 52
Detailed Contents
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Asteroid trails, curved because of parallax across an image
of a cluster of galaxies in Hubble Frontier Field Abell 370.
3.5 Amateurs Are Participating 53
3.6 Glorious Hubble After Initial Trouble 54
3.7 You Can’t Look at the Sun at Night 56
3.8 How Can You See the Invisible? 57
3.8a X-ray and Gamma-ray Telescopes 57
3.8b Telescopes for Ultraviolet Wavelengths 60
3.8c Infrared Telescopes 60
3.8d Radio Telescopes 62
Figure It Out 3.3 Angular Resolution of a
Telescope 63
A Closer Look 3.1 A Night at Maunakea 65
3.8e The Major New Radio Projects 66
4. Observing the Stars and Planets: Clockwork of the Universe
75
4.1 The Phases of the Moon and Planets 76
4.2 Celestial Spectacles: Eclipses 77
Star Party 4.1 Observing Total Solar Eclipses 80
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4.2a Eerie Lunar Eclipses 81
4.2b Glorious Solar Eclipses 82
A Closer Look 4.1 Colors in the Sky 83
4.3 Twinkle, Twinkle, Little Star … 87
4.4 The Concept of Apparent Magnitude 87
Figure It Out 4.1 Using the Magnitude Scale 88
4.5 Rising and Setting Stars 88
A Closer Look 4.2 Photographing the Stars 89
Figure It Out 4.2 Sidereal Time 90
4.6 Celestial Coordinates to Label the Sky 91
4.7 The Reason for the Seasons 92
Star Party 4.2 The Paths of the Moon and Planets 95
4.8 Time and the International Date Line 95
4.9 Calendars 98
4.10 Keeping Time 100
5. Gravitation and Motion: The Early History of Astronomy
107
5.1 A Brief Survey of the Solar System 107
Star Party 5.1 Prograde and Retrograde Motions 108
5.2 The Earth-Centered Astronomy of Ancient Greece 109
A Closer Look 5.1 Ptolemaic Terms 110
A Closer Look 5.2 The Antikythera Mechanism 111
5.3 A Heretical Idea: The Sun-Centered Universe 111
Lives in Science 5.1 Copernicus 113
5.4 The Keen Eyes of Tycho Brahe 114
5.5 Johannes Kepler and His Laws of Orbits 114
5.5a Kepler’s First Law 114
5.5b Kepler’s Second Law 114
Lives in Science 5.2 Tycho Brahe 115
A Closer Look 5.3 Kepler’s Laws 116
Lives in Science 5.3 Johannes Kepler 117
Cre
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A
The James Webb Space Telescope being tested.
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5.5c Kepler’s Third Law 118
5.6 The Demise of the Ptolemaic Model: Galileo Galilei 118
5.7 On the Shoulders of Giants: Isaac Newton 119
5.8 Clues to the Formation of Our Solar System 120
Figure It Out 5.1 Kepler’s Third Law 121
Lives in Science 5.4 Galileo Galilei 121
Star Party 5.2 Galileo’s Observations 124
A Closer Look 5.4 Newton’s Law of Universal
Gravitation 124
Figure It Out 5.2 Newton’s Version of Kepler’s Third
Law 125
Lives in Science 5.5 Isaac Newton 126
Figure It Out 5.3 Orbital Speed of Planets 127
6. The Terrestrial Planets: Earth, Moon, and Their Relatives
133
6.1 Earth: There’s No Place Like Home 134
A Closer Look 6.1 Comparative Data for the Terrestrial
Planets and Their Moons 134
6.1a Earth’s Interior 134
A Closer Look 6.2 Density 136
6.1b Continental Drift 138
6.1c Tides 139
6.1d Earth’s Atmosphere 139
6.1e The Van Allen Belts 143
6.2 The Moon 144
6.2a The Moon’s Appearance 145
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A double page from Galileo’s Sidereus Nuncius (1610) showing his
engravings of the face of the Moon as seen through his
newfangled telescope.
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A Closer Look 6.3 The First People on the
Moon 145
6.2b The Lunar Surface 146
6.2c The Lunar Interior 151
6.2d The Origin of the Moon 152
6.2e Rocks from the Moon 153
6.3 Mercury 153
6.3a The Rotation of Mercury 154
6.3b Mercury’s History 155
6.3c Mercury Observed from Earth 155
A Closer Look 6.4 Naming the Features of
Mercury 156
6.3d Spacecraft Views of Mercury 156
6.3e Mercury Research Rejuvenated 158
6.3f Mercury from MESSENGER 158
6.3g Continuing Exploration of Mercury 160
6.4 Venus 160
6.4a Transits of Venus 161
6.4b The Atmosphere of Venus 162
6.4c The Rotation of Venus 162
6.4d Why Is Venus So Incredibly Hot? 162
6.4e Spacecraft Observations of Venus’s
Atmosphere 164
6.4f Radar Observations of Venus’s Surface 165
6.4g Venus Exploration in the Twenty-First Century 166
6.5 Mars 168
6.5a Characteristics of Mars 169
6.5b Mars’s Surface 169
6.5c Mars’s Atmosphere 172Mae Jemison and Sally Ride, NASA
astronauts, in a 2017
LEGO™ set, in front of a Space Shuttle.
Cre
dit
: Jay M
. P
asach
off
NASA’s Cassini mission farewell image of Saturn and its rings.
The image is the last full mosaic taken two days before the
spacecraft plunged into Saturn.
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: N
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6.5d Mars’s Satellites 173
A Closer Look 6.5 Mars Exploration Rovers,
Mars Phoenix, and Mars Science Lab with
Curiosity 174
6.5e The Search for Life on Mars 177
6.5f Crewed Missions to Mars 180
7. The Jovian Planets: Windswept Giants 189 7.1 Jupiter 190
A Closer Look 7.1 Comparative Data for the Major
Worlds 190
Star Party 7.1 Observing the Giant Planets 191
7.1a Spacecraft to Jupiter 191
Figure It Out 7.1 The Size of Jupiter 192
7.1b The Great Red Spot 192
7.1c Jupiter’s Atmosphere 193
7.1d Jupiter’s Interior 194
7.1e Jupiter’s Magnetic Field 194
7.1f Jupiter’s Ring 195
7.1g Jupiter’s Amazing Satellites 195
A Closer Look 7.2 Jupiter and Its Satellites in
Mythology 200
7.1h JUICE at Jupiter 201
7.2 Saturn 201
7.2a Saturn’s Rings 201
7.2b Saturn’s Atmosphere 204
7.2c Saturn’s Interior and Magnetic Field 204
7.2d Saturn’s Moon Titan 204
A Closer Look 7.3 Saturn’s Satellites in
Mythology 207
7.2e Saturn’s Other Satellites 207
A Closer Look 7.4 Saturn’s Rings and Moons from
Cassini 208
7.3 Uranus 209
A Closer Look 7.5 Uranus and Neptune in
Mythology 210
Terrain on Pluto, a close-up from NASA’s New Horizons.
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7.3a Uranus’s Atmosphere 210
7.3b Uranus’s Rings 211
7.3c Uranus’s Interior and Magnetic Field 212
7.4 Neptune 212
7.4a Neptune’s Atmosphere 213
7.4b Neptune’s Interior and Magnetic Field 215
7.4c Neptune’s Rings 216
A Closer Look 7.6 Naming the Rings of
Neptune 216
7.4d Neptune’s Moon Triton 217
7.5 The Formation of the Giant Planets 218
8. Pluto, Comets, Asteroids, and Beyond 225 8.1 Pluto 226
8.1a Pluto’s Mass and Size 226
8.1b Pluto’s Atmosphere 228
8.1c What Is Pluto? 228
A Closer Look 8.1 Dwarf Planets 230
8.1d The Pluto System from New Horizons 230
8.1e Beyond Pluto 230
8.2 Kuiper-Belt Objects and Dwarf Planets 232
8.3 Comets 235
8.3a The Composition of Comets 235
8.3b The Origin and Evolution of Comets 236
8.3c Halley’s Comet 237
8.3d Comet Shoemaker–Levy 9 239
8.3e Some Bright Comets 241
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8.3f Spacecraft to Comets 243
8.3g Rosetta Orbits Its Comet 244
8.4 Meteoroids 244
8.4a Types and Sizes of Meteorites 244
8.4b Meteor Showers 247
A Closer Look 8.2 Meteor Showers 248
Star Party 8.1 Observing a Meteor Shower 248
8.5 Asteroids 249
8.5a General Properties of Asteroids 249
A Closer Look 8.3 The Extinction of the
Dinosaurs 249
8.5b Asteroids Viewed Close-Up 250
8.5c Near-Earth Objects 254
8.5d Interstellar Visitor 256
8.5e Future Asteroid Missions 256
9. Our Solar System and Others 263 9.1 The Formation of the
Solar System 264
9.1a Collapse of a Cloud 264
9.1b Models of Planet Formation 265
9.2 Extrasolar Planets (Exoplanets) 266
9.2a Astrometric Method 267
9.2b Timing of Radio Pulsars 267
9.2c Periodic Doppler Shifts: The Doppler-Wobble
Method 267
9.2d Transiting Planets: The Blink Method 269
9.2e Direct Imaging of Exoplanets 272
9.2f Gravitational Microlensing 275
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A white-dwarf star, Stein 2051 B, only 17 light-years from
Earth, seen with the Hubble Space Telescope, with a more
distant star appearing below it. The white dwarf passed
in front of the other star, providing a successful test of
Einstein’s general theory of relativity.
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A multiwavelength view of Supernova 1987A, with
green showing Hubble views of how the expanding
shock wave from the star that exploded is colliding
with material ejected previously, and the red showing
dust imaged with the ALMA millimeter/submillimeter
array. Blue is hot gas imaged with the Chandra X-ray
Observatory.
9.2g Future Observing Plans and Projects 275
9.3 The Nature of Exoplanet Systems 278
A Closer Look 9.1 Naming Stars, Exoplanets, and
Kuiper-Belt-Objects 278
9.4 Goldilocks Planets 279
9.5 Brown Dwarfs 279
9.6 Planetary Systems in Formation 280
10. Our Star: The Sun 289 10.1 What Is the Sun’s Basic
Structure? 290
10.1a The Photosphere 291
A Closer Look 10.1 The Most Common
Elements in the Sun’s Photosphere 292
10.1b The Chromosphere 294
10.1c The Corona 295
10.1d The Scientific Value of Eclipses 301
10.2 Sunspots and Other Solar Activity 302
10.2a What Are Those Blemishes on the Sun? 302
Star Party 10.1 Observing Sunspots 303
10.2b The Solar-Activity Cycle 303
10.2c Fireworks on the Sun, and Space Weather 304
10.2d Filaments and Prominences 307
10.2e Decades Ahead of Solar Monitoring 307
10.3 The Sun and the Theory of Relativity 307
Lives in Science 10.1 Albert Einstein 308
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Detailed Contents xiii
Star cluster R136 in the Tarantula Nebula in the Large
Magellanic Cloud, imaged with Hubble.
Cre
dit
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The Bubble Nebula, NGC 7635, gas expanding around a
massive star. The object is 7 light-years across, and is
imaged
here with Hubble.
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11. Stars: Distant Suns 317 11.1 Colors, Temperatures, and
Spectra of Stars 318
11.1a Taking a Star’s Temperature 318
11.1b How Do We Classify Stars? 319
11.1c The Coolest Stars 320
11.2 How Distant Are the Stars? 320
Figure It Out 11.1 Stellar Triangulation 323
11.3 How Powerful Are the Stars? 323
A Closer Look 11.1 Using Absolute Magnitudes 325
11.4 Temperature–Luminosity Diagrams 325
Figure It Out 11.2 The Inverse-Square Law 326
11.5 How Do Stars Move? 328
11.5a Proper Motions of Stars 328
Figure It Out 11.3 A Star’s Luminosity 329
11.5b Radial Velocities of Stars 329
A Closer Look 11.2 Proxima Centauri: The
Nearest Star Beyond the Sun 331
11.6 “Social Stars”: Binaries 332
Figure It Out 11.4 Doppler Shifts 333
11.6a Pairs of Stars and Their Uses 333
Figure It Out 11.5 Binary Stars 335
11.6b How Do We Weigh Stars? 337
11.6c The Mass–Luminosity Relation 337
A Closer Look 11.3 A Sense of Mass: Weighing
Stars 338
Figure It Out 11.6 The Mass–Luminosity
Relation 339
11.7 Stars That Don’t Shine Steadily 339
11.8 Clusters of Stars 343
11.8a Open and Globular Star Clusters 343
A Closer Look 11.4 Star Clusters in Our
Galaxy 344
11.8b How Old Are Star Clusters? 345
11.8c Gaia’s Hertzsprung–Russell Diagram 346
A Closer Look 11.5 How We Measure Basic
Stellar Parameters 348
12. How the Stars Shine: Cosmic Furnaces 357 12.1 Star Birth
358
12.1a Collapse of a Cloud 358
12.1b The Birth Cries of Stars 362
12.2 Where Stars Get Their Energy 364
12.3 Atoms and Nuclei 365
12.3a Subatomic Particles 365
12.3b Isotopes 365
Figure It Out 12.1 Energy Generation in the
Sun 366
12.3c Radioactivity and Neutrinos 367
12.4 Stars Shining Brightly 367
12.5 Why Stars Shine 368
12.6 Brown Dwarfs 368
12.7 The Solar Neutrino Experiment 370
12.7a Initial Measurements 370
12.7b Further Solar Neutrino Experiments 371
12.7c Beyond Solar Neutrinos 372
12.8 The End States of Stars 374
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A pair of spiral galaxies, NGC 4302 and 4298, both about 55
million light-years away and imaged with the Hubble Space
Telescope.
Cre
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A cluster of galaxies 10 billion light-years from Earth,
with
500 trillion times the mass of our Sun. Hot gas in the
middle,
imaged with the Chandra X-ray Observatory, shows as blue-
white overlaying Hubble’s visible-light image in green and
the Spitzer Space Telescope’s image in red.
Cre
dit
: N
AS
A, E
SA
, an
d M
. B
rod
win
(U
niv
ers
ity o
f M
isso
uri
)
13. The Death of Stars: Recycling 381 13.1 The Death of the Sun
381
13.1a Red Giants 381
13.1b Planetary Nebulae 383
13.1c White Dwarfs 384
13.1d Summary of the Sun’s Evolution 386
13.1e Binary Stars and Novae 387
13.2 Supernovae: Stellar Fireworks! 388
13.2a Core-Collapse Supernovae 389
13.2b White-Dwarf Supernovae (Type Ia) 391
13.2c Superluminous Supernovae 393
13.2d Observing Supernovae 393
13.2e Supernova Remnants 393
A Closer Look 13.1 Searching for
Supernovae 395
13.2f Supernovae and Us 396
13.2g Supernova 1987A! 397
13.2h Cosmic Rays 401
13.3 Pulsars: Stellar Beacons 402
13.3a Neutron Stars 402
13.3b The Discovery of Pulsars 402
13.3c What Are Pulsars? 403
13.3d The Crab, Pulsars, and Supernovae 404
13.3e Slowing Pulsars and Fast Pulsars 406
13.3f Binary Pulsars and Gravitational Waves 406
13.3g A Pulsar with a Planet 408
13.3h X-ray Binaries 408
14. Black Holes: The End of Space and Time 415 14.1 The
Formation of a Stellar-Mass Black Hole 416
14.2 The Photon Sphere 416
14.3 The Event Horizon 417
14.3a A Newtonian Argument 417
14.3b Black Holes in General Relativity 418
14.4 Time Dilation 419
14.5 Properties of Black Holes 419
14.5a Rotating Black Holes 419
14.5b Measuring Black-Hole Spin 420
14.6 Passageways to Distant Lands? 422
14.7 Detecting a Black Hole 422
14.7a Hot Accretion Disks 422
14.7b Cygnus X-1: The First Plausible Stellar-Mass
Black Hole 423
14.7c Other Black-Hole Candidates 424
Figure It Out 14.1 Binary Stars and Kepler’s
Third Law 424
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Detailed Contents xv
An all-sky map made with the European Space Agency’s Planck
spacecraft, which was also used to map the cosmic background
radiation. The image is a composite of magnetic-field, atomic
“free-free,” dust, and carbon-monoxide components.
Cre
dit
: E
uro
pean
Sp
ace A
gen
cy/P
lan
ck C
on
so
rtiu
m
14.7d The Strange Case of SS433 425
14.8 Supermassive Black Holes 426
14.9 Moderation in All Things 428
14.10 Gamma-ray Bursts: Birth Cries of Black Holes? 430
14.10a How Far Away Are Gamma-ray Bursts? 430
14.10b Models of Gamma-ray Bursts 431
14.11 Mini Black Holes 433
14.12 The Detection of Gravitational Waves 433
Proposal: The Maxwell–Einstein speed 440
15. The Milky Way: Our Home in the Universe 447 15.1 Our Galaxy:
The Milky Way 448
Star Party 15.1 Observing the Milky Way 448
15.2 The Illusion That We Are at the Center 450
15.3 Nebulae: Interstellar Clouds 451
15.4 The Parts of Our Galaxy 453
15.5 The Center of Our Galaxy 456
15.6 All-Sky Maps of Our Galaxy 460
15.7 Our Pinwheel Galaxy 461
15.8 Why Does Our Galaxy Have Spiral Arms? 463
15.9 Matter Between the Stars 464
15.10 Radio Observations of Our Galaxy 465
15.11 Mapping Our Galaxy 466
15.12 Radio Spectral Lines from Molecules 468
15.13 The Formation of Stars 468
15.14 At a Radio Observatory 471
16. A Universe of Galaxies 479 16.1 The Discovery of Galaxies
480
16.1a The Shapley–Curtis Debate 480
16.1b Galaxies: “Island Universes” 482
16.2 Types of Galaxies 483
16.2a Spiral Galaxies 483
16.2b Elliptical Galaxies 485
16.2c Other Galaxy Types 486
16.3 Habitats of Galaxies 488
16.3a Clusters of Galaxies 488
Star Party 16.1 Observing Galaxies 488
16.3b Superclusters of Galaxies 491
16.4 The Dark Side of Matter 491
16.4a The Rotation Curve of the Milky Way
Galaxy 491
16.4b Dark Matter Everywhere 493
Figure It Out 16.1 Calculating the Mass from
the Rotation Curve 494
16.4c What Is Dark Matter? 495
16.5 Gravitational Lensing 497
16.6 The Birth and Life of Galaxies 503
16.7 The Expanding Universe 503
Figure It Out 16.2 Redshifts and the Hubble–Lemaî tre
Law 505
Figure It Out 16.3 Using the Hubble–Lemaî tre Law to
Determine Distances 506
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xvi Detailed Contents
A gravitationally lensed embryonic galaxy, only half a billion
years after the big bang. It is only 1% the mass of our Milky
Way
Galaxy, and is revealing an early stage of galaxy formation. The
lensing smeared it into an arc; other galaxies about that far
away and far back in time appear only as reddish dots. The image
was taken with the Hubble Space Telescope.
NA
SA
, E
SA
, an
d B
. S
alm
on
(S
TS
cI)
16.8 The Search for the Most Distant Galaxies 506
Figure It Out 16.4 Relativistic Effects 508
16.9 The Evolution of Galaxies 511
16.10 Evolution of Large-Scale Structure 514
17. Quasars and Active Galaxies 523 17.1 Active Galactic Nuclei
524
17.2 Quasars: Denizens of the Distant Past 526
17.2a The Discovery of Quasars 526
17.2b Puzzling Spectra 527
17.2c The Nature of the Redshift 528
17.3 How Are Quasars Powered? 529
17.3a A Big Punch from a Tiny Volume 531
17.3b What Is the Energy Source? 531
17.3c Accretion Disks and Jets 532
17.4 What Are Quasars? 533
17.5 Are We Being Fooled? 536
17.6 Finding Supermassive Black Holes 537
Figure It Out 17.1 The Central Mass in a Galaxy 538
17.7 The Effects of Beaming 540
17.8 Probes of the Universe 543
18. Cosmology: The Birth and Life of the Cosmos 553 18.1
Olbers’s Paradox 554
18.2 An Expanding Universe 555
18.2a The Hubble-Lemaître Law 555
18.2b Expansion Without a Center 556
18.2c What Is Actually Expanding? 558
18.3 The Age of the Universe 559
18.3a Finding Out How Old 559
Figure It Out 18.1 The Hubble Time 560
18.3b The Quest for Hubble’s Constant 560
18.3c A Key Project of the Hubble Space
Telescope 562
18.3d Deviations from Uniform Expansion 566
18.3e Type Ia Supernovae as Cosmological
Yardsticks 566
18.4 The Geometry and Fate of the Universe 567
18.4a The Cosmological Principle: Uniformity 567
18.4b No “Cosmological Constant”? 567
18.4c Three Kinds of Possible Universes 569
Figure It Out 18.2 The Critical Density and
ΩM
569
A Closer Look 18.1 Finite Flat and Hyperbolic
Universes 571
18.4d Two-Dimensional Analogues 572
18.4e What Kind of Universe Do We Live In? 573
18.4f Obstacles Along the Way 574
18.5 Measuring the Expected Deceleration 574
18.5a The High-Redshift Hubble Diagram 574
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Detailed Contents xvii
18.5b Type Ia (White-Dwarf) Supernovae 575
18.5c An Accelerating Universe! 575
18.5d Einstein’s Biggest Blunder? 577
18.5e Dark Energy 578
18.5f The Cosmic Jerk 579
18.6 The Future of the Universe 581
19. In the Beginning 589 19.1 The Steady-State Theory 590
19.2 The Cosmic Microwave Background Radiation 591
19.2a A Faint Hiss from All Directions 591
19.2b Origin of the Microwave Radiation 592
19.3 Deviations from Isotropy 594
19.3a Ripples in the Cosmic Microwave
Background 594
19.3b The Overall Geometry of the Universe 595
19.3c The Wilkinson Microwave Anisotropy Probe
(WMAP) 596
19.3d The Planck Spacecraft 596
19.3e Evaluating the Cosmic Background
Radiation 596
19.3f Planck Maps Objects in Space 599
Cre
dit
: Jay M
. P
asach
off
A balloon alien, as yet unknown in reality.
19.3g Ground-Based Telescopes for the Cosmic
Background Radiation 599
19.3h Polarization of the Cosmic Background
Radiation 599
19.4 The Early Universe 600
19.4a Going Back in Time 600
19.4b A Brief History of the Early
Universe 602
19.4c Primordial Nucleosynthesis 604
19.5 The Inflationary Universe 606
19.5a Problems with the Original Big-Bang
Model 606
19.5b Inflation to the Rescue 607
Figure It Out 19.1 Inflation of the Early
Universe 609
19.5c Forces in the Universe 609
19.5d Supercooling the Universe 612
19.5e Successes of Inflation 612
19.5f The Ultimate Free Lunch? 613
Figure It Out 19.2 Virtual Particles 614
19.6 A Universe of Universes 614
19.7 A Universe Finely Tuned for Life? 616
20. Life in the Universe 623 20.1 The Origin of Life 624
20.2 Life in the Solar System 626
20.3 Suitable Stars for Intelligent Life 626
20.4 The Search for Extraterrestrial Intelligence 627
Figure It Out 20.1 Interstellar Travel and Einstein’s
Relativity 628
20.5 Communicating with Extraterrestrials 632
20.6 The Statistics of Intelligent Extraterrestrial Life 633
20.6a The Drake Equation 633
20.6b Where Is Everyone? 635
Figure It Out 20.2 The Drake Equation 636
20.7 UFOs and the Scientific Method 637
20.7a UFOs 637
20.7b Of Truth and Theories 639
20.8 Conclusion 639
Epilogue 644
Appendix 1/2. Measurement Systems/Basic Constants 645
Appendix 3. Planets and Dwarf Planets 647
Appendix 4. The Brightest Stars 649
Appendix 5. The Nearest Stars 651
Appendix 6. The Messier Catalogue 654
Appendix 7. The Constellations 656
Appendix 8. Star Names 658
Selected reading 661
Glossary 668
Index 685
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Saturn and Mars at their closest places to Earth as they orbit,
the oppositions of 2018, imaged with the Hubble Space
Telescope.
Saturn’s northern-hemisphere summer triggered a large storm,
seen here as it disintegrates near Saturn’s north pole. Mars’s
southern-hemisphere spring triggered a huge dust storm that
eventually covered the whole planet.
NA
SA
, E
SA
, and S
TS
cI
NA
SA
, E
SA
, and S
TS
cI
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xix
Astronomy continues to flourish, with huge discoveries such as
the
one that pairs of giant black holes merge, sending ripples
through
space-time – so-called gravitational waves – that we can pick up
on
Earth. Even the merger of a pair of neutron stars has been
detected
not only from the gravitational waves – let’s say by ear, given
the
“chirp” of detection – but also with ordinary telescopes, the
eyes of
the Universe. So, as of 2018, we have the eyes and the ears of
the
Universe working together.
The Universe’s expansion – which was long thought to be
slow-
ing down – is, astonishingly, accelerating, presumably as a
conse-
quence of mysterious “dark energy.” We have discovered
thousands
of planets around other stars – other solar systems abound! A
gen-
eration of large optical telescopes has been built on
mountaintops,
and arrays of dozens of radio telescopes such as the Atacama
Large
Millimeter/submillimeter Array (ALMA) at an extremely
high-alti-
tude site explore their part of the spectrum at high resolution.
Still
larger telescopes are being planned or built, including the
Thirty
Meter Telescope, the Giant Magellan Telescope, and the
European
Extremely Large Telescope, all for optical and near-infrared
studies,
and the Daniel K. Inouye Solar Telescope in Hawaii for
detailed
studies of the Sun. The Hubble Space Telescope, with its
latest
updated set of cameras, sends down exciting data all the time,
and
we anticipate the launch in 2019 of the James Webb Space
Telescope
with its mirror much larger than Hubble’s. The latest space
obser-
vatories transmit images made with gamma rays, with x-rays,
and
with infrared radiation. The overall structure of the Universe
is
being mapped and analyzed, with catalogues of millions of
objects
being compiled. Cosmology has become an observationally rich
science.
In Solar System studies, NASA’s Curiosity rover triumphantly
travels around Mars, bearing instruments to investigate Mars’s
past
habitability. The Cassini spacecraft that orbited Saturn for 13
years
plunged into its surface in 2017, to protect Saturn’s moons
from
being contaminated with terrestrial microbes. Spacecraft
recently
orbited the asteroid and dwarf planet Ceres and a comet.
Another
spacecraft flew right by Pluto and its moons and is now en route
to a
tiny object beyond them. Moreover, new electronic instruments
and
computer capabilities, new space missions to Solar-System
objects,
and advances in computational astronomy and in theoretical
work
will continue to bring forth exciting results.
In this latest edition of The Cosmos: Astronomy in the New
Millennium, we describe the current state of astronomy, both
the
fundamentals of astronomical knowledge that have been built
up
over decades and the incredible advances that are now taking
place.
We want simply to share with students the excitement and
magnifi-
cence of the Universe.
We try to cover all branches of astronomy without slighting
any
of them; each teacher and each student may well find special
inter-
ests that are different from our own. One of our aims in writing
this
book is to educate citizens in the hope that they will
understand the
value and methods of scientific research in general and
astronomical
research in particular.
In writing this book, we share the goals of a commission of
the
Association of American Colleges, whose report on the college
cur-
riculum stated:
A person who understands what science is recognizes that
scientific
concepts are created by acts of human intelligence and
imagination;
comprehends the distinction between observation and inference
and
between the occasional role of accidental discovery in
scientific inves-
tigation and the deliberate strategy of forming and testing
hypoth-
eses; understands how theories are formed, tested, validated,
and
accorded provisional acceptance; and discriminates between
conclu-
sions that rest on unverified assertion and those that are
developed
from the application of scientific reasoning.
The scientific method permeates the book.
Preface
The dot between two of Saturn’s rings is Earth, our planet.
NASA’s
Cassini spacecraft orbited in the Saturn system through
2017,
when it was directed to plunge into Saturn’s atmosphere to
safely
destroy it without risking contaminating any of Saturn’s
moons
with terrestrial life-forms.
NA
SA/J
PL-C
alte
ch/S
pace
Sci
ence
Inst
itut
e
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xx Preface
What is science? The following statement was originally
drafted
by the Panel on Public Affairs of the American Physical Society,
in
an attempt to meet the perceived need for a very short
statement
that would differentiate science from pseudoscience. This
state-
ment has been endorsed as a proposal to other scientific
societies
by the Council of the American Physical Society, and was
endorsed
by the Executive Board of the American Association of
Physics
Teachers:
Science is the systematic enterprise of gathering knowledge
about the
world and organizing and condensing that knowledge into
testable
laws and theories. The success and credibility of science is
anchored
in the willingness of scientists to:
Expose their ideas and results to independent testing and
replica-
tion by other scientists; this requires the complete and open
exchange
of data, procedures, and materials;
Abandon or modify accepted conclusions when confronted with
more complete or reliable experimental evidence. Adherence to
these
principles provides a mechanism for self-correction that is the
foun-
dation of the credibility of science.
Our book, through the methods it describes, should reveal this
sys-
tematic enterprise of science to the readers.
Because one cannot adequately cover the whole Universe in a
few
months, or even a year, we have had to pick and choose topics
from
within the various branches of astronomy, while trying to
describe a
wide range, to convey the spirit of contemporary astronomy and
of
the scientists working in it. Our mix includes much basic
astronomy
and many of the exciting topics now at the forefront.
Two examples are the currently hottest topics in astronomy:
the
discovery of thousands of planets around other stars (so-called
ex-
oplanets) and the discovery of gravitational waves from
merging
black holes and neutron stars. Our exoplanet coverage brings
the
discoveries and the new techniques and spacecrat being used
up
to 2018, with a graph of the Kepler spacecrat’s discoveries,
men-
tion of the K2 version of the spacecrat including an image with
its
ields of view overlain, and a discussion of new instruments,
such
as NASA’s Transiting Exoplanet Survey Satellite (TESS),
launched
in 2018.
For the fantastic discovery of gravitational waves from
collisions of
black holes over a billion light-years away, which was honored
with
the 2017 Nobel Prize in Physics, we have expanded our previous
cov-
erage of the Laser Interferometer Gravitational-wave
Observatory
(LIGO). We include the latest update to the graph of spiraling
neu-
tron stars that led to an indirect veriication of the existence
of grav-
itational waves, which was recognized with the 1993 Nobel Prize
in
Physics. Moreover, we discuss LIGO’s August 2017 detection of
two
such neutron stars merging, and the result not only of the
gravita-
tional waves themselves but also of concomitant gamma rays,
visible
light, and other forms of electromagnetic waves.
For the 2017 total solar eclipse whose path crossed the
United
States, we have the latest imaging and a discussion of why such
ob-
servations were scientiically important.
Anyone choosing an astronomy textbook should consider the
following:
• Readability. Our prose is extremely clear and readable.
• Scientific accuracy. Our book is written by experts in the
field and
has the various chapters checked by other experts.
• Up to date. Our book has sunspot numbers up to date to show
the
current phase of the sunspot cycle; exoplanet lists and diagrams
up
to the current situation; the latest on the Cassini mission to
Saturn
and to Curiosity roaming around on Mars; images of the
corona
at the 2017 total solar eclipse; a discussion of the Hubble
constant
and the expansion of the Universe, with slightly different
values
coming from an overall measurement of the cosmic background
radiation from the Planck spacecraft compared with the latest
val-
ues of the Universe’s expansion and acceleration from
supernova
observations; and more.
• Features like A Closer Look, Figure It Out, and Star Party
that help
this book be useful for astronomy survey courses of one
semester
or of those that spread the material out over two or more
semesters.
NEW IN THIS EDITION
• Updated data (such as sunspot numbers showing the current
min-
imum of the sunspot cycle) and figures throughout the text, as
well
as new images from recent space missions (such as the Cassini
mis-
sion to Saturn as well as Curiosity roaming around on Mars)
and
ground-based telescopes (such as images of the corona at the
2017
total solar eclipse).
• Expanded discussions of the hottest current topics, such as
New
Horizons’ flyby of Pluto (Chapter 8), the latest on
exoplanets
(Chapter 9) and dark matter (Chapter 18), and the direct
detection
of gravitational waves by LIGO (Chapter 14).
• The latest discoveries on supernovae, including pictures of
the first
known strongly gravitationally lensed supernova (showing
five
separate images of that supernova).
• New observations of the 4-million-solar-mass black hole at
the
center of our Milky Way Galaxy.
• The latest progress on precision measurement of the Hubble
con-
stant for the expansion of the Universe.
• Additional end-of-chapter questions and updated summaries
and
glossary.
ORGANIZATION
The fifth edition of The Cosmos: Astronomy in the New Millennium
is
generally organized in an Earth-outward approach. Chapter 1
gives
an overview of the Universe. Chapter 2 presents fundamental
astro-
nomical concepts about light, matter, and energy, while Chapter
3
summarizes the various types of telescopes used to explore
the
electromagnetic spectrum. In Chapter 4, we discuss easily
observed
astronomical phenomena and the celestial sphere. Some
professors
prefer to cover that material at the very beginning of the
course or at
other points, and there is no problem with doing so.
Chapter 5 examines the early history of the study of
astronomy.
Chapters 6 through 8 cover the Solar System and its
occupants,
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Preface xxi
although a thorough discussion of the Sun is reserved for later,
in
Chapter 10. Chapter 6 compares Earth to the Moon and Earth’s
nearest planetary neighbors, Venus and Mars. Based largely on
the
Voyager, Galileo, and Cassini data, Chapter 7 compares and
contrasts
the Jovian gas/liquid giants – Jupiter, Saturn, Uranus, and
Neptune.
Chapter 8 looks at the outermost part of the Solar System,
including
Pluto and its moon, Charon, as well as other Kuiper-belt objects
still
farther out; the chapter also spotlights comets and meteoroids,
the
Solar System’s vagabonds. Chapter 9 discusses the formation of
our
own Solar System and describes the exciting discovery of
thousands
of exoplanets and exoplanet candidates around other stars.
Chapter 10 concentrates on the Sun, our nearest star,
exploring
its various components and the solar activity cycle. Moving
out-
ward, Chapters 11 through 14 examine all aspects of stars.
Chapter
11 begins by presenting observational traits of stars – their
colors
and types – and goes on to show how we measure their
distances,
brightnesses, and motions. It also discusses binary stars,
variable
stars, and star clusters, in the process showing how we derive
stellar
masses and ages. Chapter 12 answers the question of how stars
shine
and reveals that all stars have life cycles. Chapter 13 tells
what hap-
pens when stars die and describes some of the peculiar objects
that
violent stellar death can create, including neutron stars and
pulsars.
Black holes, the most bizarre objects to result from star death,
are the
focus of Chapter 14. We end the chapter by describing how the
Laser
Interferometer Gravitational-wave Observatory (LIGO)
detected,
several times, the tiniest possible variation in the length of a
light
beam, with the waves interpreted as coming from the merger of
two
black holes each containing 10−30 times as much mass as the
Sun.
And in August 2017, LIGO even detected the merger of two
neutron
stars simultaneously with telescopes around the world and in
space
seeing the event in ordinary, electromagnetic radiation. We are
in the
era of “Multi-Messenger Astronomy,” as NASA has recently put
it:
“photons, gravitational waves, and particle astrophysics.”
As we explore further, Chapter 15 describes the parts of the
Milky
Way Galaxy and our place in it. Chapter 16 pushes beyond the
Milky
Way to discuss galaxies in general, the fundamental units of
the
Universe, and evidence that they consist largely of dark matter.
Ways
in which we are studying the evolution of galaxies are also
described.
Chapter 17 looks at quasars, distant and powerful objects that
shine
because gigantic black holes are swallowing gas in the central
regions
of galaxies.
Chapters 18 and 19 consider the ultimate questions of cosmo-
logical creation by analyzing recent findings and current
theories.
Evidence that the expansion of the Universe is currently
speeding
up with time (probably propelled by a mysterious “dark
energy”),
possibilities for the overall geometry and fate of the Universe,
rip-
ples in the cosmic background radiation, the origin and early
expo-
nential growth of the Universe, and the idea of multiple
universes
are among the fascinating (and sometimes very speculative)
topics
explored. Lastly, Chapter 20 discusses the always-intriguing
search
for extraterrestrial intelligence.
FEATURES
The Cosmos: Astronomy in the New Millennium offers instructors
a
concise overview of a wide range of astronomical topics. An
early
discussion of the scientific method stresses its importance in
the ver-
ification of observations. The text presents up-to-date coverage
of
many important findings and theories as well as the latest
images,
including observations of Jupiter and Saturn from the
Cassini–
Huygens mission (including the landing on Titan), close-up
obser-
vations of Mars, images of stars in formation and of gas near
them
from the largest telescopes in space, and coverage of recent
total
solar eclipses and of the pair of transits of Venus – the like
of which
will not be seen on Earth until the year 2117, in the
twenty-second
century.
We provide, as well, a sampling of the many significant
find-
ings from the Hubble Space Telescope. Numerous images from
the
Chandra X-ray Observatory, the Spitzer Space Telescope, the
Planck
spacecraft that studied the cosmic background radiation, and
the
Gaia spacecraft that is mapping a billion of the nearest stars,
also
appear, as do results from the Swift spacecraft that is
monitoring
gamma-ray bursts, among the most powerful and violent
phenom-
ena in the Universe (the origin of one type of which is now
proven
by observations of the merging neutron stars). Of particular
interest
is the recent advance in our understanding of the age and
expansion
of the Universe, both through better measurements of the
current
expansion rate and through the discovery that the Universe’s
expan-
sion is now speeding up with time. We also present the recent
excit-
ing measurements that allow astronomers to determine the
overall
geometry of the Universe and the early appearance of
large-scale
structure through detailed observations of the cosmic
background
radiation.
PEDAGOGY
1. Chapteropener. Each chapter includes the following
features:
• Origins. NASA has chosen Origins as one of its major
themes
for the organization of its missions and has several
spacecraft
in the Origins program. Inspired by this choice, each
chapter
piques the reader’s interest with some of the discoveries,
tools,
and theories behind our effort to understand the Universe
and
its relationship to us.
• Chapter introduction, summarizing the main topics
discussed
in each chapter and how these fit into the rest of the book.
• Aims, setting out what students should expect to learn
from
the material that follows.
2. StarParties. An occasional feature that shows students how
to
find things in the sky. These include observing exercises and
links
to the star maps that appear on the inside covers of the book.
For
example, Star Party 5.1 explains how to sketch the position
of
Mars or Jupiter in relation to the stars near them, repeating
this
exercise every 6–9 days over the course of 2–3 months.
Students
examine their results to see the planets in their prograde and
ret-
rograde motions, which are important to understand in order
to
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xxii Preface
properly comprehend the work of Copernicus and how it super-
seded the model of Ptolemy.
3. FigureItOut. In some astronomy courses, it may be
appropri-
ate to elaborate on equations. Because we wrote The Cosmos:
Astronomy in the New Millennium to be a descriptive
presenta-
tion of modern astronomy for liberal-arts students, we kept
the use of mathematics to a minimum. However, we recognize
that some instructors wish to introduce their students to
more
of the mathematics associated with astronomical phenomena.
Consequently, we provide mathematical features, numbered so
they can be assigned or not, at the instructor’s option. Figure
It
Out 5.1, for example, gives a mathematical treatment of
Kepler’s
third law that can be included in a course in a way that is easy
to
mark on a syllabus; similarly, Figure It Out 5.2 gives
professors the
option of introducing Newton’s formulation of Kepler’s third
law
to find masses.
4. LivesinScience. These boxes provide biographies of
important
historical figures like 5.1 Copernicus, 5.2 Tycho, 5.3 Kepler,
5.4
Galileo, and 5.5 Newton. Lives in Science 10.1 discusses
Albert
Einstein.
5. ACloserLook. Using these boxes, students can further
explore
interesting topics, such as size scales in the Universe,
observing
with large telescopes, various celestial phenomena,
mythology,
and naming systems. For example, we are pleased to supply
some
exciting new close-up views of Mars from NASA’s Curiosity
rover
that is now on its surface in A Closer Look 6.5, whereas in A
Closer
Look 5.1 we specifically define the main features of the
Ptolemaic
system: deferent, epicycle, and equant.
6. Keywordsandglossary. New vocabulary is boldfaced in the
text
and in the expanded summaries that are given at the end of
each
chapter, and defined in the glossary.
7. Chaptersummary. Each chapter includes the following
features:
• Concept Review, summarizing the main topics discussed.
• Questions. An expanded set of end-of-chapter questions
cov-
ers a range of material and includes some that are straight-
forward to answer from the text and others that require more
thought.
• Topics for Discussion. A list of themes and questions aimed
at
engaging students in deeper explorations of the material
dis-
cussed in each chapter.
8. Appendices for additional coverage. Appendices at the end
of
the book provide additional information on planets, stars,
con-
stellations, and nonstellar objects.
9. SkyMaps. Inside the covers of the book, students will find
the
exceptionally beautiful sky maps by Wil Tirion to help them
find
their way around the sky when they go outside to observe the
stars.
ONLINE RESOURCES
Adopters of The Cosmos, 5th edition, can access a rich array of
teach-
ing and learning resources at http://thecosmos5.com. The
website
(together with the authors’ personal website
http://www.solarcorona
.net) is regularly updated to include the latest discoveries and
photo-
graphs from various sources. It features the following:
• Multiple-choice self-tests and other useful information such
as lists
of typographical errors, updates to various new scientific
discov-
eries since the publication of the textbook, and links to
websites
such as those with new discoveries as yet unknown at the time
of
this printing.
• “Misconceptions.” Recent educational research has shown that
stu-
dents often need to unlearn incorrect ideas in order to
understand
the correct ones. A list of these misconceptions – as well as
the
correct alternatives – is available on our website.
• Links to relevant websites on a wide variety of astronomical
mate-
rial, such as http://photojournal.jpl.nasa.gov for planetary
images;
http://sidc.oma.be/silso for the latest sunspot cycle plots;
http://
spaceweather.com for the latest on daily sunspots or
auroras;
and http://hubblesite.org for a wide range of new Hubble
Space
Telescope observations.
• People in Astronomy. A series of interviews presenting a
famous
contemporary astronomer engaged in conversation about a
variety of topics, such as: current and future work in
astron-
omy, what led that person to study and pursue astronomy as
a career, and why learning about astronomy is an important
scientific and human endeavor. We interviewed a diverse set
of astronomers – diverse both personally and in astronomical
field of study. We discussed Saturn with Carolyn Porco, the
head of the Saturn imaging team on the Cassini spacecraft;
brown dwarfs and exoplanet astronomy with Gibor Basri and
how he got interested in astronomy; space astronomy with
Jeff
Hoffman, a former astronaut who helped upgrade the Hubble
Space Telescope in orbit; and Sandra Faber about galaxies.
We
hope that students enjoy reading their comments as much as
we enjoyed speaking with them and learning about their
varied
interests and backgrounds.
STAR CHARTS
Pasachoff ’s Peterson Field Guide to the Stars and Planets is a
suggested
accompaniment for those wanting monthly star maps, star
charts,
and other detailed observing aids; see
http://www.solarcorona.com.
Quarterly star maps, improved and redrawn for us for The
Cosmos:
Astronomy for the New Millennium by the foremost celestial
cartog-
rapher, Wil Tirion of The Netherlands, appear on the inside
covers
in The Cosmos, 5th edition.
ACKNOWLEDGMENTS
The publishers join us in placing a heavy premium on accuracy,
and
we have made certain that the manuscript and past editions
have
been carefully read and considered. As a result, students will
find that
the statements in this book, brief as they are, are
authoritative.
This fifth edition of The Cosmos benefited from new and
updated
photographs and comments on text from Seth Shostak (SETI
Institute)
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Preface xxiii
on SETI, Daniel Wertheimer (University of California, Berkeley)
on
SETI, Lynn Cominsky (Sonoma State University) on gamma-ray
astron-
omy, Leon Golub (Harvard-Smithsonian Center for Astrophysics)
on
heliophysics, Joel Weisberg (Carleton College) on gravitational
waves
from the double pulsar, Richard Manchester (CSIRO, Australia)
on
pulsars, Rosemary Killen (NASA’s Goddard Space Flight
Center)
and Carl Schmidt (University of Virginia) on Mercury,
Augustin
Sanchez Lavega (Valencia) on the winds of Jupiter and Saturn,
Laura
Brenneman (Harvard-Smithsonian Center for Astrophysics) on
future
x-ray missions, Alan Guth (MIT) and Adrienne Erickcek
(University
of North Carolina) on the inflationary universe, and Eric
Nash
(NASA’s Goddard Space Flight Center) on the ozone hole. We
also
thank William Graham for useful comments. The fourth edition
of
The Cosmos benefited from the advice and special images
provided
by Lynn Cominsky (Sonoma State University), Leon Golub
(Harvard-
Smithsonian Center for Astrophysics), Joel Weisberg
(Carleton
College), Daniel Seaton (Royal Observatory of Belgium), John
Johnson
(Harvard-Smithsonian Center for Astrophysics), Robert Simmon
(NASA’s Goddard Space Flight Center), Richard McCray (University
of
Colorado), Richard Manchester (CSIRO, Australia), Daniel Stern
(Jet
Propulsion Laboratory), Daniel Mortlock (Imperial College,
London),
Matthew Templeton and Arne Hernden (AAVSO), Stefan Fichtel
(Ixtract), Federica Bianco (Las Cumbres Observatory Global
Telescope
Network and the University of California, Santa Barbara),
Gareth
Williams (Harvard-Smithsonian Center for Astrophysics),
Lorne
McKee (National Resources Canada), Jens Vellev (Aarhus
University),
Gerard van Belle (Lowell Observatory), Geoff Marcy (University
of
California, Berkeley), Wayne Hammond (Chapin Library of
Williams
College), and Axel Mellinger (Central Michigan University).
At the time of proof for the fifth edition, we benefitted
from
additional consultations with Gerald Williger (U. Louisville;
cur-
rently a Fulbright Scholar at Konkoly Observatory) on the
full
set of chapters; Mark Showalter (SETI Institute), Jupiter’s
moons;
Carolyn Porco (Southwest Research Institute),
Cassini/Saturn;
Imke de Pater (U. California, Berkeley), outer planets; Lindy
Elkins-
Tanton (Arizona State U.), lunar minerals and water; Beatriz
Garcia (Pierre Auger Observatory, Argentina), cosmic rays;
David
Ehrenreich (U. Geneva), exoplanets; Bruce Elmegreen (IBM)
and
Clare Dobbs (U. Exeter), M51 modeling; Mansi Kasliwal
(Caltech),
Palomar Transient Factory and Zwicky Telescope Facility; Doug
Gies
(Georgia State U.), CHARA; Howard Bond (Penn State and
STScl),
V838 Cygni; Lorenzo Reynard (South African Radio Astronomy
Observatory), Square Kilometer Array; Marek Demianski
(Williams
College and University of Warsaw), supernovae and cosmology;
Alan Stern and Cathy Olkin (SwRI), Dale Cruikshank (NASA
Ames),
Rick Binzel (MIT), Bill McKinnon (Washington U.), Pluto; and
Eric Mamajek (NASA’s JPL-Caltech), planetary and stellar data
and
names.
For her extensive editorial consulting, we thank Madeline
Kennedy
in Williamstown. For additional assistance, we thank Michele
Rech
in Williamstown.
At Cambridge University Press, we thank our commissioning
editor Vince Higgs, and Ilaria Tassistro and her editorial team,
as well
as Charlie Howell and his production team.
J.M.P. thanks various members of his family, who have pro-
vided vital and valuable editorial services in addition to their
gen-
eral support. His wife, Naomi, has always been very helpful
both
personally and editorially. He is grateful for the family
support of
Deborah Pasachoff/Ian Kezsbom/Lily Kezsbom/Jacob Kezsbom/
Xander Kezsbom and of Eloise Pasachoff/Tom Glaisyer/Samuel
Glaisyer/Jessica Glaisyer.
A.F. thanks his children, Zoe, Simon, Caprielle, and Orion
Filippenko, for the long hours they endured while he was busy
work-
ing on this book rather than spending time with them; they
mean
the universe to him. A.F. also thanks his wife, Noelle
Filippenko, for
her incredible patience, advice, and support; he could not have
suc-
ceeded without her, and he looks forward to sharing more of
the
wonders of the cosmos with her.
We are extremely grateful to all the individuals named above
for
their assistance. Of course, it is we who have put this all
together,
and we alone are responsible for the content. We would
appreciate
hearing from readers with suggestions for improved
presentation
of topics, with comments about specific points that need
clarifi-
cation, with typographical or other errors, or just to tell us
about
your astronomy course. We invite readers to write to us,
respec-
tively, at Williams College, Hopkins Observatory, 33 Lab
Campus
Drive, Williamstown, MA 01267–2565, [email protected],
and
Department of Astronomy, University of California, Berkeley,
CA
94720–3411, [email protected], or through the book’s
web-
sites. We promise a personal response to each writer.
Jay Pasachoff
Alex Filippenko
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Cambridge University Press978-1-108-43138-5 — The Cosmos5th
EditionFrontmatterMore Information
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A close-up view of the surface of dwarf planet Pluto, taken as
NASA’s New Horizons spacecraft lew by on July 14, 2015, along with
a full-disk view taken as the spacecraft
approached. The heart-shaped region is Sputnik Planitia. At
bottom right, in enhanced color, we see features that rise
1.5 miles high, scarred by clusters of pits 5–8 miles across
and
up to 1.5 miles deep, deeper than our Earth’s Grand Canyon.
NASA/Johns Hopkins University Applied Physics
Laboratory/Southwest Research Institute
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