Astronomy Today

Cover
Brief Contents
Contents
About the Authors
Preface
PART I: Astronomy and the Universe
	1 Charting the Heavens
		The Foundations of Astronomy
		1.1 Our Place in Space
		1.2 Scientific Theory and the Scientific Method
		1.3 The “Obvious” View
		1.4 Earth’s Orbital Motion
			MORE PRECISELY 1-1 Angular Measure
		1.5 The Motion of the Moon
		1.6 The Measurement of Distance
			MORE PRECISELY 1-2 Measuring Distances with Geometry
		Chapter Review
	2 The Copernican Revolution
		The Birth of Modern ­Science
		2.1 Ancient Astronomy
		2.2 The Geocentric Universe
		2.3 The Heliocentric Model of the Solar System
			DISCOVERY 2-1 Foundations of the Copernican Revolution
		2.4 The Birth of Modern Astronomy
		2.5 The Laws of Planetary Motion
			MORE PRECISELY 2-1 Some Properties of Planetary Orbits
		2.6 The Dimensions of the Solar System
		2.7 Newton’s Laws
		2.8 Newtonian Mechanics
			MORE PRECISELY 2-2 Weighing the Sun
		Chapter Review
	3 Radiation
		Information from the Cosmos
		3.1 Information from the Skies
		3.2 Waves in What?
		3.3 Electromagnetic Spectrum
		3.4 Thermal Radiation
			DISCOVERY 3-1 The Wave Nature of Radiation
			MORE PRECISELY 3-1 The Kelvin Temperature Scale
			MORE PRECISELY 3-2 More About the Radiation Laws
		3.5 The Doppler Effect
			MORE PRECISELY 3-3 Measuring Velocities with the Doppler Effect
		Chapter Review
	4 Spectroscopy
		The Inner Workings of Atoms
		4.1 Spectral Lines
		4.2 Atoms and Radiation
			DISCOVERY 4-1 The Photoelectric Effect
			MORE PRECISELY 4-1 The Hydrogen Atom
		4.3 Formation of Spectral Lines
		4.4 Molecules
		4.5 Spectral-Line Analysis
		Chapter Review
	5 Telescopes
		The Tools of Astronomy
		5.1 Optical Telescopes
		5.2 Telescope Size
		5.3 Images and Detectors
		5.4 High-Resolution Astronomy
		5.5 Radio Astronomy
		5.6 Interferometry
		5.7 Space-Based Astronomy
			DISCOVERY 5-1 The ALMA Array
		5.8 Full-Spectrum Coverage
		Chapter Review
PART II: Our Planetary System
	6 The Solar System
		Comparative Planetology and ­Formation Models
		6.1 An Inventory of the Solar System
		6.2 Measuring the Planets
		6.3 The Overall Layout of the Solar System
		6.4 Terrestrial and Jovian Planets
		6.5 Interplanetary Matter
			DISCOVERY 6-1 Gravitational “Slingshots”
		6.6 How Did the Solar System Form?
			DISCOVERY 6-2 Spacecraft Exploration of the Solar System
			MORE PRECISELY 6-1 Angular Momentum
		6.7 Jovian Planets and Planetary Debris
		Chapter Review
	7 Earth
		Our Home in Space
		7.1 Overall Structure of Planet Earth
		7.2 Earth’s Atmosphere
			MORE PRECISELY 7-1 Why Is the Sky Blue?
			DISCOVERY 7-1 The Greenhouse Effect and Global Warming
		7.3 Earth’s Interior
			MORE PRECISELY 7-2 Radioactive Dating
		7.4 Surface Activity
		7.5 Earth’s Magnetosphere
		7.6 The Tides
		Chapter Review
	8 The Moon and Mercury
		Scorched and Battered Worlds
		8.1 Orbital Properties
		8.2 Physical Properties
		8.3 Surface Features
		8.4 Rotation Rates
		MORE PRECISELY 8-1 Why Air Sticks Around
		DISCOVERY 8-1 Lunar Exploration
		8.5 Lunar Cratering and Surface Composition
		8.6 The Surface of Mercury
		8.7 Interiors
		8.8 Origin of the Moon
		8.9 Evolutionary History of the Moon and Mercury
		Chapter Review
	9 Venus
		Earth’s Sister Planet
		9.1 Orbital Properties
		9.2 Physical Properties
		9.3 Long-Distance Observations of Venus
		9.4 The Surface of Venus
		9.5 The Atmosphere of Venus
		9.6 Venus’s Magnetic Field and Internal Structure
		Chapter Review
	10 Mars
		A Near Miss for Life?
		10.1 Orbital Properties
		10.2 Physical Properties
		10.3 Long-Distance Observations of Mars
		10.4 The Martian Surface
		10.5 Water on Mars
			DISCOVERY 10-1 Life on Mars?
		10.6 The Martian Atmosphere
		10.7 Martian Internal Structure
		10.8 The Moons of Mars
		Chapter Review
	11 Jupiter
		Giant of the Solar System
		11.1 Orbital and Physical Properties
		11.2 Jupiter’s Atmosphere
		11.3 Internal Structure
			DISCOVERY 11-1 A Cometary Impact
		11.4 Jupiter’s Magnetosphere
			DISCOVERY 11-2 Almost a Star?
		11.5 The Moons of Jupiter
		11.6 Jupiter’s Ring
		Chapter Review
	12 Saturn
		Spectacular Rings and Mysterious Moons
		12.1 Orbital and Physical Properties
		12.2 Saturn’s Atmosphere
		12.3 Saturn’s Interior and Magnetosphere
		12.4 Saturn’s Spectacular Ring System
		12.5 The Moons of Saturn
			DISCOVERY 12-1 Dancing Among Saturn’s Moons
		Chapter Review
	13 Uranus and Neptune
		The Outer Worlds of the Solar ­System
		13.1 The Discoveries of Uranus and Neptune
		13.2 Orbital and Physical Properties
		13.3 The Atmospheres of Uranus and Neptune
		13.4 Magnetospheres and Internal Structure
		13.5 The Moon Systems of Uranus and Neptune
		13.6 The Rings of the Outermost Jovian Planets
		Chapter Review
	14 Solar System Debris
		Keys to Our Origin
		14.1 Asteroids
		14.2 Comets
			DISCOVERY 14-1 What Killed the Dinosaurs?
		14.3 Beyond Neptune
		14.4 Meteoroids
		Chapter Review
	15 Exoplanets
		Planetary Systems Beyond Our Own
		15.1 Modeling Planet Formation
		15.2 Solar System Regularities and Irregularities
		15.3 Exoplanet Detection
		15.4 Exoplanet Properties
			DISCOVERY 15-1 Gravitational Microlensing
		15.5 Is Our Solar System Unusual?
		Chapter Review
PART III: Stars and Stellar Evolution
	16 The Sun
		Our Parent Star
		16.1 Physical Properties of the Sun
		16.2 The Solar Interior
			DISCOVERY 16-1 Eavesdropping on the Sun
		16.3 The Sun’s Atmosphere
		16.4 Solar Magnetism
		16.5 The Active Sun
			DISCOVERY 16-2 Solar–Terrestrial Relations
		16.6 The Heart of the Sun
			MORE PRECISELY 16-1 Fundamental Forces
		16.7 Observations of Solar Neutrinos
			MORE PRECISELY 16-2 Energy Generation in the Proton—Proton Chain
		Chapter Review
	17 The Stars
		Giants, Dwarfs, and the Main Sequence
		17.1 The Solar Neighborhood
		17.2 Luminosity and Apparent Brightness
		17.3 Stellar Temperatures
			MORE PRECISELY 17-1 More on the Magnitude Scale
		17.4 Stellar Sizes
		17.5 The Hertzsprung–Russell Diagram
			MORE PRECISELY 17-2 Estimating Stellar Radii
		17.6 Extending the Cosmic Distance Scale
		17.7 Stellar Masses
		17.8 Mass and Other Stellar Properties
			MORE PRECISELY 17-3 Measuring Stellar Masses in Binary Stars
		Chapter Review
	18 The Interstellar Medium
		Gas and Dust Among the Stars
		18.1 Interstellar Matter
		18.2 Emission Nebulae
		18.3 Dark Dust Clouds
		18.4 21-Centimeter Radiation
		18.5 Interstellar Molecules
		Chapter Review
	19 Star Formation
		A Traumatic Birth
		19.1 Star-Forming Regions
			MORE PRECISELY 19-1 Competition in Star Formation
		19.2 Formation of Stars Like the Sun
		19.3 Stars of Other Masses
		19.4 Observations of Cloud Fragments and Protostars
			DISCOVERY 19-1 Observations of Brown Dwarfs
		19.5 Shock Waves and Star Formation
		19.6 Star Clusters
			DISCOVERY 19-2 Eta Carinae
		Chapter Review
	20 Stellar Evolution
		The Life and Death of a Star
		20.1 Leaving the Main Sequence
		20.2 Evolution of a Sun-Like Star
		20.3 The Death of a Low-Mass Star
			DISCOVERY 20-1 Learning Astronomy from History
		20.4 Evolution of Stars More Massive than the Sun
			DISCOVERY 20-2 Mass Loss from Giant Stars
		20.5 Observing Stellar Evolution in Star Clusters
		20.6 Stellar Evolution in Binary Systems
		Chapter Review
	21 Stellar Explosions
		Novae, Supernovae, and the ­Formation of the Elements
		21.1 Life After Death for White Dwarfs
		21.2 The End of a High-Mass Star
		21.3 Supernovae
		21.4 Formation of the Elements
			DISCOVERY 21-1 Supernova 1987A
		21.5 The Cycle of Stellar Evolution
		Chapter Review
	22 Neutron Stars and Black Holes
		Strange States of Matter
		22.1 Neutron Stars
		22.2 Pulsars
		22.3 Neutron-Star Binaries
		22.4 Gamma-Ray Bursts
		22.5 Black Holes
		22.6 Einstein’s Theories of Relativity
			DISCOVERY 22-1 Special Relativity
		22.7 Space Travel Near Black Holes
		22.8 Observational Evidence for Black Holes
			MORE PRECISELY 22-1 Tests of General Relativity
			DISCOVERY 22-2 Gravitational Waves: A New Window on the Universe
		Chapter Review
PART IV: Galaxies and Cosmology
	23 The Milky Way Galaxy
		A Spiral in Space
		23.1 Our Parent Galaxy
		23.2 Measuring the Milky Way
			DISCOVERY 23-1 Early “Computers”
		23.3 Galactic Structure
		23.4 Formation of the Milky Way
		23.5 Galactic Spiral Arms
			DISCOVERY 23-2 Density Waves
		23.6 The Mass of the Milky Way Galaxy
		23.7 The Galactic Center
		Chapter Review
	24 Galaxies
		Building Blocks of the Universe
		24.1 Hubble’s Galaxy Classification
		24.2 The Distribution of Galaxies in Space
		24.3 Hubble’s Law
		24.4 Active Galactic Nuclei
			MORE PRECISELY 24-1 Relativistic Redshifts and Look-Back Time
		24.5 The Central Engine of an Active Galaxy
		Chapter Review
	25 Galaxies and Dark Matter
		The Large-Scale Structure of the Cosmos
		25.1 Dark Matter in the Universe
		25.2 Galaxy Collisions
		25.3 Galaxy Formation and Evolution
			DISCOVERY 25-1 The Sloan Digital Sky Survey
		25.4 Black Holes in Galaxies
		25.5 The Universe on Large Scales
		Chapter Review
	26 Cosmology
		The Big Bang and the Fate of the ­Universe
		26.1 The Universe on the Largest Scales
		26.2 The Expanding Universe
		26.3 The Fate of the Cosmos
		26.4 The Geometry of Space
			MORE PRECISELY 26-1 Curved Space
		26.5 Will the Universe Expand Forever?
			DISCOVERY 26-1 Einstein and the Cosmological Constant
		26.6 Dark Energy and Cosmology
		26.7 The Cosmic Microwave Background
		Chapter Review
	27 The Early Universe
		Toward the Beginning of Time
		27.1 Back to the Big Bang
		27.2 Evolution of the Universe
			MORE PRECISELY 27-1 More on Fundamental Forces
		27.3 Formation of Nuclei and Atoms
		27.4 The Inflationary Universe
		27.5 Large-Scale Structure in the Universe
		27.6 Cosmic Structure and the Microwave Background
		Chapter Review
	28 Life in the Universe
		Are We Alone?
		28.1 Cosmic Evolution
			DISCOVERY 28-1 The Virus
		28.2 Life in the Solar System
		28.3 Intelligent Life in the Galaxy
		28.4 The Search for Extraterrestrial Intelligence
		Chapter Review
Appendices
	APPENDIX 1 Scientific Notation
	APPENDIX 2 Astronomical Measurement
	APPENDIX 3 Tables
GLOSSARY
ANSWERS TO CHECK QUESTIONS
ANSWERS TO SELF-TEST QUESTIONS
PHOTO CREDITS/TEXT PERMISSIONS
INDEX
STAR CHARTS