Alien Skies: A Travelogue of the Universe

Contents
Acknowledgments
Foreword
Destination 1: The Moon: Out First Step off Earth
	1.1 - In Search of Alien Skies
	1.2 - The Sky from Home
	1.3 - Our First Step
Destination 2: The View From Mars
	2.1 - Terror and Fear in the Sky of Mars
	2.2 - The Riddle of Planetary Motion
	2.3 - Kepler’s Third Law: The Triumph of Simplicity
Destination 3: The Sky from Earth: A Last Look from Home
	3.1 - Preparations for a Long Voyage
	3.2 - Navigating in the Sky
	3.3 - The Distances of Stars: Stellar Parallax
Destination 4: The Sky from α Centauri
	4.1 - A Familiar Light in an Alien Sky
	4.2 - An Alien Light in an Alien Sky
	4.3 - A Faint Light in an Alien Sky
Destination 5: The ‘Empty’ Sky of Deep Space: At ‘Anti-Centauri’
	5.1 - No Place in Particular
	5.2 - The Matter of ‘Empty Space’
	5.3 - Seeing the Invisible: Neutral Hydrogen and 21-cm Radiation
	5.4 - Hot Matter in Cold Space
Destination 6: The Orion Nebula
	6.1 - Secrets of a Celestial Hunter
	6.2 - The Bright Sky of the Orion Nebula
	6.3 - The Dark Clouds of the Orion Nebula
	6.4 - The Stars of the Orion Nebula
Destination 7: Extrasolar Planetary Systems: 51 Pegasi
	7.1 - A Star in Pegasus
	7.2 - What We Really Came to See
	7.3 - The Properties and Formation of Planetary Systems
	7.4 - Do Planets Imply Life?
Destination 8: The Pleiades
	8.1 - A Sky Without Night
	8.2 - The Stars of the Pleiades Cluster
	8.3 - The Spectra of Stars
	8.4 - Why Do Stars Shine?
Destination 9: Exploring the Milky Way
	9.1 - Our Home’s Home
	9.2 - Rising up from the Milky Way
	9.3 - The Galactic Disk
	9.4 - Through the Galactic Plane
	9.5 - Rotation of the Galaxy
	9.6 - A Summary of a Fantastic Journey
Destination 10: Inward Bound: The Galactic Center
	10.1 - To the Galactic Center: Through the Inner Galactic Disk
	10.2 - To the Galactic Center: From the Disk to the Bulge
	10.3 - A Strange New World: The Galactic Center
Destination 11: A Blazing Sky of Stars: The Globular Cluster M 92
	11.1 - Summer in Paris
	11.2 - The Sky Ablaze: The View from M 92
	11.3 - Stellar Death
	11.4 - White Dwarfs: The Corpses of Low-Mass Stars
	11.5 - A Window to an Ancient Past
	11.6 - A Different Way to Stay Together
Destination 12: The Magellanic Clouds: The Nearest Galaxies
	12.1 - The Magellanic Clouds: Beyond the Galaxy
	12.2 - The Case of the Missing White Dwarfs
	12.3 - The Evolution of High-Mass Stars
	12.4 - Witnessing High-Mass Stellar Evolution
	12.5 - Victory of a Relentless Force
Destination 13: Through the Heart of Darkness: The Galactic Halo
	13.1 - The Lonely Outskirts of the Galaxy
	13.2 - Dark Matter in the Galactic Halo
	13.3 - The Structure of the Galactic Halo
Destination 14: The Nearby Spiral Galaxies M 31 and M 33
	14.1 - Leaving Our Galaxy Behind
	14.2 - Cepheid Variable Stars: A New Way to Estimate Extragalactic Distances
	14.3 - The Galaxy, M 31, and M 33: The Closest Spiral Galaxies
	14.4 - What are Spiral Arms?
	14.5 - The Peculiar Role of Dark Matter
	14.6 - The Local Group
Destination 15: The Giant Elliptical Galaxy Maffei 1
	15.1 - Beyond the Local Group
	15.2 - Maffei 1: A Giant Elliptical Galaxy
	15.3 - Classifying Galaxies: The Hubble Sequence
Destination 16: The Virgo Cluster: A Sky of Galaxies
	16.1 - The Virgo Cluster of Galaxies
	16.2 - Galaxies in Collision
	16.3 - The Hubble Law
	16.4 - The Dark Matter of the Virgo Cluster
Destination 17: There’s Something Strange Here: The Seyfert Galaxy M 77
	17.1 - The Monster in the Middle
	17.2 - The Two Faces of the Monster
	17.3 - The Name of the Monster
	17.4 - Einstein’s Legacy: An Introduction
	17.5 - Einstein’s Legacy: Getting Personal
	17.6 - The Maw of the Monster
	17.7  - In Memoriam
Destination 18: The Boötes Void
	18.1 - Mapping the Distribution of Galaxies
	18.2 - The Dark Lumpy Universe
	18.3 - ‘Light’ in the Darkness: The Cosmic Microwave Background
Destination 19: Back in Time to a Distant Galaxy Cluster
	19.1 - Navigating Space and Time
	19.2 - Telling Time in the Universe
	19.3 - What Kind of Universe Do We Inhabit?
	19.4 - MS1054-0321: A Galaxy Cluster at z=0.8
Destination 20: High Redshift Galaxies: The Young and Restless Universe
	20.1 - The Galaxies of the Early Universe
	20.2 - The Golden Era of Galaxy Formation
Destination 21: Quasars at the Dawn of Galaxy Formation
	21.1 - Young Galaxies and ‘False Stars’
	21.2 - Quasars: Extreme Active Galactic Nuclei
	21.3 - Quasars in the Early Universe: Implications for Galaxy Formation
Destination 22: The Dark Ages
	22.1 - A Simpler Universe
	22.2 - The Problem with Being Smooth, Part 1: Why So Lumpy Now?
	22.3 - The Problem with Being Smooth, Part 2: Why Is the CMB So Uniform?
Destination 23: The Era of Recombination
	23.1 - Into the Fog
	23.2 - Lifting the Veil: The Era of ‘Re’-combination
	23.3 - The Seeds of Creation
Destination 24: The First Elements in the Universe
	24.1 - The Evolution of the Chemical Elements: Getting Started
	24.2 - Fusion in an Expanding Universe
Destination 25: To a Time Before Time
	25.1 - The Genesis of Matter
	25.2 - The Genesis of Physical Forces and the Inflation Era
	25.3 - As Far as We Can Go: The Planck Time
Appendices
	Appendix A - Summary of Destinations
	Appendix B - Units, Symbols, and Conversion Factors
	Appendix C - Constants
	Appendix D - Mathematical Formulae
	Appendix E - Basic Data for Selected Planets and Dwarf Planets of the Solar System
	Appendix F - The Constellations of Earth’s Sky
	Appendix G - The Natural Chemical Elements
Figure Credits
Index