The Complete Idiot's Guide to Astronomy (Complete Idiot's Guide To...)

457 Pages·2003·9.04 MB·English

by  Claire J. Creutzfeldt

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Astronomy
Second Edition
by Christopher De Pree and Alan Axelrod
A Pearson Education Company
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To my girls, Julia, Claire, and Madeleine (CGD)
For my stars, Anita and Ian (AA)
Copyright © 2001 by The Ian Samuel Group, Inc.
All rights reserved. No part of this book shall be reproduced, stored in a retrieval sys-
tem, or transmitted by any means, electronic, mechanical, photocopying, recording,
or otherwise, without written permission from the publisher. No patent liability is as-
sumed with respect to the use of the information contained herein. Although every
precaution has been taken in the preparation of this book, the publisher and authors
assume no responsibility for errors or omissions. Neither is any liability assumed for
damages resulting from the use of information contained herein. For information, ad-
dress Alpha Books, 201 West 103rd Street, Indianapolis, IN 46290.
THE COMPLETE IDIOT’S GUIDE TO and Design are registered trademarks of Pearson
Education, Inc.
International Standard Book Number:1-5925-7003-8��
Library of Congress Catalog Card Number: 2001091092
03 02 01 8 7 6 5 4 3 2 1
Interpretation of the printing code: The rightmost number of the first series of num-
bers is the year of the book’s printing; the rightmost number of the second series of
numbers is the number of the book’s printing. For example, a printing code of 01-1
shows that the first printing occurred in 2001.
Printed in the United States of America
Note: This publication contains the opinions and ideas of its authors. It is intended to
provide helpful and informative material on the subject matter covered. It is sold with
the understanding that the authors and publisher are not engaged in rendering profes-
sional services in the book. If the reader requires personal assistance or advice, a com-
petent professional should be consulted.
The authors and publisher specifically disclaim any responsibility for any liability,
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directly, of the use and application of any of the contents of this book.
Making or distributing electronic copies of this book constitutes copyright
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Publisher
Marie Butler-Knight
Product Manager
Phil Kitchel
Managing Editor
Jennifer Chisholm
Acquisitions Editor
Mike Sanders
Development Editor
Amy Gordon
Production Editor
Billy Fields
Copy Editor
Amy Lepore
Illustrator
Brian Moyer
Cover Designers
Mike Freeland
Kevin Spear
Book Designers
Scott Cook and Amy Adams of DesignLab
Indexer
Lisa Wilson
Layout/Proofreading
Angela Calvert
Svetlana Dominguez
Mary Hunt
Gloria Schurick
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Contents at a Glance
Part 1: Finding Our Place in Space 1
1 Naked Sky, Naked Eye: Finding Your Way in the Dark 3
Finding your way around the night sky. No telescope
necessary.
2 Ancient Evenings: The First Watchers 17
What the ancient astronomers saw, thought, and said.
3 The Unexplained Motions of the Heavens 31
Puzzles of planetary motion: early thoughts on the subject.
4 Astronomy Reborn: 1543–1687 47
Everything (well, not really) you need to know about
Copernicus, Tycho Brahe, Kepler, Galileo, and Newton.
Part 2: Now You See It (Now You Don’t) 63
5 The Art of Collecting Light (with a Telescope) 65
Telescopes: what they see and how they work.
6 You and Your Telescope 81
A guide to choosing and using binoculars and telescopes.
7 Over the Rainbow 101
Electromagnetic radiation: what it is, how it travels, and
what it does.
8 Seeing in the Dark 117
Alternatives to visible-light astronomy: radio, infrared,
ultraviolet, and high energy.
9 Space Race: From Sputnik to the International
Space Station 131
A brief history of space exploration.
Part 3: A Walk Around the Block 147
10 The Moon: Our Closest Neighbor 149
All about Earth’s moon.
11 Solar System Home Movie 161
How our solar system was born and developed.
12 Solar System Family Snapshot 173
A tour through our solar system.
13 So Close and Yet So Far: The Inner Planets 189
The lowdown on Mercury, Venus, and Mars.
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14 Great Balls of Gas! The Outer Planets 205
All about Uranus, Neptune, Jupiter, and Saturn.
15 The Far End of the Block 221
The moons and rings of the jovian planets, and the
story of Pluto.
Part 4: To the Stars 235
16 Our Star 237
We explore the sun.
17 Of Giants and Dwarfs: Stepping Out into the Stars 251
Observing, measuring, and classifying stars.
18 Stellar Careers 267
How stars evolve—and how they end their lives.
19 Black Holes: One-Way Tickets to Eternity 279
Stellar endgames: neutron stars, black holes, and the
strange effects they produce.
20 Stellar Nurseries 289
How stars are created.
Part 5: Way Out of This World 301
21 The Milky Way: Much More Than a Candy Bar 303
A tour of our home Galaxy.
22 A Galaxy of Galaxies 317
Observing, measuring, and classifying galaxies.
23 Moving Out of Town 331
Active versus normal galaxies: Seyfert and radio galaxies,
plus quasars.
Part 6: The Big Questions 341
24 Table for One? 343
The odds on life beyond Earth and on other civilizations
in the Milky Way.
25 What About the Big Bang? 359
How it all began (we think).
26 (How) Will It End? 369
Is the universe infinite or finite? Eternal or mortal? Will it
end—and if so, how?
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Appendixes
A Star Words Glossary 379
A glossary of astronomy.
B Upcoming Eclipses 395
A list of lunar and solar eclipses to watch for.
C The Constellations 397
A complete list of the constellations with their approxi-
mate positions.
D The Messier Catalog 401
The classic list of deep-sky objects—available to amateur
astronomers.
E Sources for Astronomers 407
Key sources of information, including books, guides, charts,
astronomical event calendars, and Internet resources.
Index 413
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Contents
Part 1: Finding Our Place in Space 1
1 Naked Sky, Naked Eye: Finding Your Way
in the Dark 3
Sun Days ........................................................................................3
Flat Earth, Big Bowl ........................................................................4
Man in the Moon............................................................................5
Lights and Wanderers ....................................................................7
Celestial Coordinates ......................................................................7
Measuring the Sky ..........................................................................9
The Size of Things, or “I Am Crushing Your Head!” ........................9
Celestial Portraits..........................................................................11
The Dippers First ..........................................................................12
The Stars of Spring ......................................................................13
Summer Nights ............................................................................13
Fall Constellations........................................................................14
Winter Skies ................................................................................15
Who Cares? ..................................................................................16
2 Ancient Evenings: The First Watchers 17
A Dragon Eats the Sun: Ancient Chinese Astronomy ................18
Why the Emperor Executed Hsi and Ho ........................................18
Time, Space, Harmony..................................................................19
Babylon Revisited ........................................................................20
The Venus Tablet..........................................................................20
Draftsmen of the Constellations? ..................................................21
Egypt Looks ..................................................................................22
Celestial Pyramids ........................................................................22
The Universe-in-a-Box ..................................................................23
Stonehenge and the New World ..................................................23
Grecian Formula ..........................................................................24
Anaximander Puts Earth in Space ................................................24
Anaximenes Says Stars Burn ........................................................25
Pythagoras Calls Earth a Globe ....................................................25
Anaxagoras Explains Eclipses ......................................................26
Aristarchus Sets the Sun in the Middle and Us in Motion ..............26
Eratosthenes Sizes Up the Earth ....................................................26
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The Complete Idiot’s Guide to Astronomy, Second Edition
3 The Unexplained Motions of the Heavens 31
Time on Our Hands......................................................................32
What Really Happens in a Day? ..................................................32
A Month of Moons ......................................................................34
Another Wrinkle in Time ..............................................................37
To Everything a Season ................................................................38
The Sun Goes Dark, the Moon Becomes Blood ..........................41
Aristotle Lays Down the Law ......................................................41
Ptolemy’s Picture ..........................................................................43
Night Falls ....................................................................................44
4 Astronomy Reborn: 1543–1687 47
Arabian Nights..............................................................................48
Heresy of a Polish Priest ..............................................................49
“More Pleasing to the Mind” ........................................................50
A Revolution of Revolutions ..........................................................52
The Man with the Golden Nose ..................................................53
Kepler Makes Sense of It ..............................................................54
Three Laws ..................................................................................55
Galileo’s Eye..................................................................................57
Holding It All Together ................................................................58
Newton’s Three Laws of Motion ....................................................59
Weighty Matters ..........................................................................60
It’s Not Just a Good Idea … ..........................................................60
Part 2: Now You See It (Now You Don’t) 63
5 The Art of Collecting Light (with a Telescope) 65
Slice of Light ................................................................................66
The Whole Spectrum ....................................................................67
Buckets of Light............................................................................69
The Telescope Is Born ..................................................................69
Refraction … ................................................................................70
… or Reflection? ..........................................................................71
Variations on an Optical Theme ..................................................73
Size Matters ..................................................................................74
The Power to Gather Light ............................................................75
The Power to Resolve an Image ....................................................75
Twinkle, Twinkle ..........................................................................75
Computer Assist ..........................................................................76
Fun House Mirrors ........................................................................77
Observatory in Space: The Hubble Space Telescope ....................78
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Contents
6 You and Your Telescope 81
Do I Really Need a Telescope?......................................................82
Science Aside, What Will It Cost?................................................87
Decisions, Decisions ....................................................................89
Refractors: Virtues and Vices ........................................................89
Reflectors: Newton’s Favorite ........................................................90
Rich-Field Telescopes: Increasing in Popularity ..............................90
Schmidt-Cassegrain: High-Performance Hybrid..............................90
Maksutov-Cassegrain: New Market Leader ....................................91
Dobsonians: More for Your Money? ..............................................92
The Go-To Revolution ..................................................................93
I’ve Bought My Telescope, Now What? ......................................94
Grab a Piece of Sky ......................................................................94
Become an Astrophotographer ......................................................95
Light Pollution and What to Do About It......................................96
Finding What You’re Looking For..................................................97
Learning to See ............................................................................98
Low-Light Adjustment ..................................................................98
Don’t Look Too Hard ....................................................................99
7 Over the Rainbow 101
Making Waves ............................................................................102
Anatomy of a Wave....................................................................102
New Wave..................................................................................104
Big News from Little Places ........................................................104
Full Spectrum..............................................................................105
The Long and the Short of It ......................................................106
What Makes Color?....................................................................107
Heavenly Scoop ..........................................................................108
Atmospheric Ceilings and Skylights ............................................109
The Black-Body Spectrum............................................................110
Watch Your Head, Here Comes an Equation................................111
Read Any Good Spectral Lines Lately? ........................................112
8 Seeing in the Dark 117
Dark Doesn’t Mean You Can’t See ............................................118
A Telephone Man Tunes In ........................................................118
Anatomy of a Radio Telescope ....................................................121
Bigger Is Better: The Green Bank Telescope ..................................121
Interference Can Be a Good Thing ..............................................123
What Radio Astronomers “See” ................................................124
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