Astronomy 2e

Senior Contributing Authors

Andrew Fraknoi, Fromm Institute, University of San Francisco
David Morrison, NASA (Emeritus) and SETI Institute
Sidney Wolff, NOIRLab (Emerita)



Contributing Authors

John Beck, Stanford University
Susan D. Benecchi, Planetary Science Institute
John Bochanski, Rider University
Howard Bond, Pennsylvania State University, Emeritus, Space Telescope Science Institute
Jennifer Carson, Occidental College
Bryan Dunne, University of Illinois at Urbana-Champaign
Martin Elvis, Harvard-Smithsonian Center for Astrophysics
Debra Fischer, Yale University
Heidi Hammel, Association of Universities for Research in Astronomy
Tori Hoehler, NASA Ames Research Center
Douglas Ingram, Texas Christian University
Steven Kawaler, Iowa State University
Lloyd Knox, University of California, Davis
Todd Young, Wayne State College
Mark Krumholz, Australian National University
James Lowenthal, Smith College
Siobahn Morgan, University of Northern Iowa
Daniel Perley, California Institute of Technology
Claire Raftery, National Solar Observatory
Deborah Scherrer, retired, Stanford University
Phillip Scherrer, Stanford University
Sanjoy Som, Blue Marble Space Institute of Science, NASA Ames Research Center
Wes Tobin, Indiana University East
William H. Waller, retired, Tufts University, Rockport (MA) Public Schools

Chapter 1 Science and the Universe: A Brief Tour
• Introduction
• 1.1 The Nature of Astronomy
• 1.2 The Nature of Science
• 1.3 The Laws of Nature
• 1.4 Numbers in Astronomy
• 1.5 Consequences of Light Travel Time
• 1.6 A Tour of the Universe
• 1.7 The Universe on the Large Scale
• 1.8 The Universe of the Very Small
• 1.9 A Conclusion and a Beginning
• For Further Exploration

Chapter 2 Observing the Sky: The Birth of Astronomy
• Thinking Ahead
• 2.1 The Sky Above
• 2.2 Ancient Astronomy
• 2.3 Astrology and Astronomy
• 2.4 The Birth of Modern Astronomy
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 3 Orbits and Gravity
• Thinking Ahead
• 3.1 The Laws of Planetary Motion
• 3.2 Newton’s Great Synthesis
• 3.3 Newton’s Universal Law of Gravitation
• 3.4 Orbits in the Solar System
• 3.5 Motions of Satellites and Spacecraft
• 3.6 Gravity with More Than Two Bodies
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 4 Earth, Moon, and Sky
• Thinking Ahead
• 4.1 Earth and Sky
• 4.2 The Seasons
• 4.3 Keeping Time
• 4.4 The Calendar
• 4.5 Phases and Motions of the Moon
• 4.6 Ocean Tides and the Moon
• 4.7 Eclipses of the Sun and Moon
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 5 Radiation and Spectra
• Thinking Ahead
• 5.1 The Behavior of Light
• 5.2 The Electromagnetic Spectrum
• 5.3 Spectroscopy in Astronomy
• 5.4 The Structure of the Atom
• 5.5 Formation of Spectral Lines
• 5.6 The Doppler Effect
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 6 Astronomical Instruments
• Thinking Ahead
• 6.1 Telescopes
• 6.2 Telescopes Today
• 6.3 Visible-Light Detectors and Instruments
• 6.4 Radio Telescopes
• 6.5 Observations outside Earth’s Atmosphere
• 6.6 The Future of Large Telescopes
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 7 Other Worlds: An Introduction to the Solar System
• Thinking Ahead
• 7.1 Overview of Our Planetary System
• 7.2 Composition and Structure of Planets
• 7.3 Dating Planetary Surfaces
• 7.4 Origin of the Solar System
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 8 Earth as a Planet
• Thinking Ahead
• 8.1 The Global Perspective
• 8.2 Earth’s Crust
• 8.3 Earth’s Atmosphere
• 8.4 Life, Chemical Evolution, and Climate Change
• 8.5 Cosmic Influences on the Evolution of Earth
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 9 Cratered Worlds
• Thinking Ahead
• 9.1 General Properties of the Moon
• 9.2 The Lunar Surface
• 9.3 Impact Craters
• 9.4 The Origin of the Moon
• 9.5 Mercury
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 10 Earthlike Planets: Venus and Mars
• Thinking Ahead
• 10.1 The Nearest Planets: An Overview
• 10.2 The Geology of Venus
• 10.3 The Massive Atmosphere of Venus
• 10.4 The Geology of Mars
• 10.5 Water and Life on Mars
• 10.6 Divergent Planetary Evolution
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 11 The Giant Planets
• Thinking Ahead
• 11.1 Exploring the Outer Planets
• 11.2 The Giant Planets
• 11.3 Atmospheres of the Giant Planets
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 12 Rings, Moons, and Pluto
• Thinking Ahead
• 12.1 Ring and Moon Systems Introduced
• 12.2 The Galilean Moons of Jupiter
• 12.3 Titan and Triton
• 12.4 Pluto and Charon
• 12.5 Planetary Rings (and Enceladus)
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 13 Comets and Asteroids: Debris of the Solar System
• Thinking Ahead
• 13.1 Asteroids
• 13.2 Asteroids and Planetary Defense
• 13.3 The “Long-Haired” Comets
• 13.4 The Origin and Fate of Comets and Related Objects
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 14 Cosmic Samples and the Origin of the Solar System
• Thinking Ahead
• 14.1 Meteors
• 14.2 Meteorites: Stones from Heaven
• 14.3 Formation of the Solar System
• 14.4 Comparison with Other Planetary Systems
• 14.5 Planetary Evolution
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 15 The Sun: A Garden-Variety Star
• Thinking Ahead
• 15.1 The Structure and Composition of the Sun
• 15.2 The Solar Cycle
• 15.3 Solar Activity above the Photosphere
• 15.4 Space Weather
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 16 The Sun: A Nuclear Powerhouse
• Thinking Ahead
• 16.1 Sources of Sunshine: Thermal and Gravitational Energy
• 16.2 Mass, Energy, and the Theory of Relativity
• 16.3 The Solar Interior: Theory
• 16.4 The Solar Interior: Observations
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 17 Analyzing Starlight
• Thinking Ahead
• 17.1 The Brightness of Stars
• 17.2 Colors of Stars
• 17.3 The Spectra of Stars (and Brown Dwarfs)
• 17.4 Using Spectra to Measure Stellar Radius, Composition, and Motion
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 18 The Stars: A Celestial Census
• Thinking Ahead
• 18.1 A Stellar Census
• 18.2 Measuring Stellar Masses
• 18.3 Diameters of Stars
• 18.4 The H–R Diagram
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 19 Celestial Distances
• Thinking Ahead
• 19.1 Fundamental Units of Distance
• 19.2 Surveying the Stars
• 19.3 Variable Stars: One Key to Cosmic Distances
• 19.4 The H–R Diagram and Cosmic Distances
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 20 Between the Stars: Gas and Dust in Space
• Thinking Ahead
• 20.1 The Interstellar Medium
• 20.2 Interstellar Gas
• 20.3 Cosmic Dust
• 20.4 Cosmic Rays
• 20.5 The Life Cycle of Cosmic Material
• 20.6 Interstellar Matter around the Sun
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 21 The Birth of Stars and the Discovery of Planets outside the Solar System
• Thinking Ahead
• 21.1 Star Formation
• 21.2 The H–R Diagram and the Study of Stellar Evolution
• 21.3 Evidence That Planets Form around Other Stars
• 21.4 Planets beyond the Solar System: Search and Discovery
• 21.5 Exoplanets Everywhere: What We Are Learning
• 21.6 New Perspectives on Planet Formation
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 22 Stars from Adolescence to Old Age
• Thinking Ahead
• 22.1 Evolution from the Main Sequence to Red Giants
• 22.2 Star Clusters
• 22.3 Checking Out the Theory
• 22.4 Further Evolution of Stars
• 22.5 The Evolution of More Massive Stars
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 23 The Death of Stars
• Thinking Ahead
• 23.1 The Death of Low-Mass Stars
• 23.2 Evolution of Massive Stars: An Explosive Finish
• 23.3 Supernova Observations
• 23.4 Pulsars and the Discovery of Neutron Stars
• 23.5 The Evolution of Binary Star Systems
• 23.6 The Mystery of the Gamma-Ray Bursts
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 24 Black Holes and Curved Spacetime
• Thinking Ahead
• 24.1 Introducing General Relativity
• 24.2 Spacetime and Gravity
• 24.3 Tests of General Relativity
• 24.4 Time in General Relativity
• 24.5 Black Holes
• 24.6 Evidence for Black Holes
• 24.7 Gravitational Wave Astronomy
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 25 The Milky Way Galaxy
• Thinking Ahead
• 25.1 The Architecture of the Galaxy
• 25.2 Spiral Structure
• 25.3 The Mass of the Galaxy
• 25.4 The Center of the Galaxy
• 25.5 Stellar Populations in the Galaxy
• 25.6 The Formation of the Galaxy
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 26 Galaxies
• Thinking Ahead
• 26.1 The Discovery of Galaxies
• 26.2 Types of Galaxies
• 26.3 Properties of Galaxies
• 26.4 The Extragalactic Distance Scale
• 26.5 The Expanding Universe
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 27 Active Galaxies, Quasars, and Supermassive Black Holes
• Thinking Ahead
• 27.1 Quasars
• 27.2 Supermassive Black Holes: What Quasars Really Are
• 27.3 Quasars as Probes of Evolution in the Universe
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 28 The Evolution and Distribution of Galaxies
• Thinking Ahead
• 28.1 Observations of Distant Galaxies
• 28.2 Galaxy Mergers and Active Galactic Nuclei
• 28.3 The Distribution of Galaxies in Space
• 28.4 The Challenge of Dark Matter
• 28.5 The Formation and Evolution of Galaxies and Structure in the Universe
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 29 The Big Bang
• Thinking Ahead
• 29.1 The Age of the Universe
• 29.2 A Model of the Universe
• 29.3 The Beginning of the Universe
• 29.4 The Cosmic Microwave Background
• 29.5 What Is the Universe Really Made Of?
• 29.6 The Inflationary Universe
• 29.7 The Anthropic Principle
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself

Chapter 30 Life in the Universe
• Thinking Ahead
• 30.1 The Cosmic Context for Life
• 30.2 Astrobiology
• 30.3 Searching for Life beyond Earth
• 30.4 The Search for Extraterrestrial Intelligence
• Key Terms
• Summary
• For Further Exploration
• Collaborative Group Activities
Exercises
o Review Questions
o Thought Questions
o Figuring for Yourself