Table of Contents for Isaac Asimov's Guide to Earth and Space

Introduction 1
1 What Is the Shape of the Earth? 2
2 What Is the Size of the Earth? 6
3 If the Earth Is a Sphere, Why Don't We Slide Off? 10
4 Does the Earth Move? 11
5 When You Jump Up, Why Don't You Come Down in a Different Place? 14
6 What Makes the Wind Blow? 16
7 Why Is Summer Warmer than Winter? 18
8 How Do We Measure Time? 21
9 How Do We Measure Time Intervals Less than a Day Long? 23
10 How Old Is the Earth? 26
11 How Was the Age of the Earth Finally Determined? 29
12 What Is Mass? 31
13 What Is the Mass of the Earth? 33
14 What Is Density? 34
15 Is the Earth Hollow? 35
16 What Is the Earth's Interior Really Like? 37
17 Do the Continents Move? 40
18 What Causes Earthquakes and Volcanoes? 43
19 What Is Heat? 48
20 What Is Temperature? 48
21 How Do We Measure Temperature? 50
22 What Is Energy? 52
23 Is It Possible to Run Out of Energy? 55
24 What Is the Internal Temperature of the Earth? 56
25 Why Doesn't the Earth Cool Off? 57
26 Does the Sky Turn in One Piece? 59
27 Is the Earth the Center of the Universe? 62
28 Once Again, Then, Is the Earth the Center of the Universe? 64
29 Can Copernicus' View Be Improved? 68
30 How Was the Earth Formed? 70
31 Is the Earth a Magnet? 74
32 Is the Earth a Perfect Sphere? 76
33 Why Does the Moon Change Its Shape? 79
34 Does the Earth Shine? 81
35 Why Are There Eclipses of the Sun and the Moon? 82
36 Does the Moon Turn? 85
37 How Far Away Is the Moon? 87
38 What Is the Mass of the Moon? 89
39 What Are the Tides? 92
40 How Do the Tides Affect the Earth? 94
41 Is There Life on the Moon? 95
42 What Caused the Craters on the Moon? 98
43 How Was the Moon Formed? 99
44 Can We Reach the Moon? 103
45 What Are Meteorites? 107
46 Might Meteorites Be Dangerous to Life and Property? 109
47 What Are Asteroids? 110
48 Are There Asteroids Only in the Asteroid Belt? 112
49 What Are Comets? 115
50 Why Do Comets Look Fuzzy? 117
51 What Happens to Comets? 119
52 Where Do Comets Come From? 120
53 How Far Is the Sun? 121
54 Is the Earth Large? 123
55 Are There Planets the Ancients Didn't Know? 125
56 In What Ways Are the Giant Planets Different? 127
57 Is There Life on Venus? 131
58 Is There Life on Mars? 134
59 Is There Life in the Outer Solar System? 137
60 What Does the Sun Look Like? 141
61 What Is Sunlight? 143
62 What Are Spectral Lines? 145
63 What Is the Mass of the Sun? 147
64 What Is the Sun Made Of? 148
65 What Are the Planetary Bodies Made Of? 149
66 How Hot Is the Sun? 152
67 What Is the Solar Corona? 154
68 What Are Solar Flares? 156
69 Why Doesn't the Sun Cool Off? 157
70 How Does Nuclear Energy Power the Sun? 160
71 Are There Stars the Ancients Didn't Know? 163
72 Are the Fixed Stars Really Fixed? 164
73 Is There a Sphere of the Stars? 166
74 What Are Stars? 167
75 How Far Are the Stars, Actually? 168
76 How Fast Does Light Travel? 171
77 What Is a Light-Year? 174
78 Is the Sun Moving? 175
79 Are the Laws of Nature the Same Everywhere? 176
80 What Are Variable Stars? 179
81 How Do Stars Differ from One Another? 180
82 What Happens When the Hydrogen Supply of a Star Runs Low? 183
83 Will Our Sun Ever Become a Red Giant? 185
84 Why Do Very Luminous Stars Still Exist? 186
85 What Is a White Dwarf? 187
86 What Is a Nova? 191
87 What Is a Supernova? 194
88 Is There Anything Useful About Supernovas? 198
89 Is There Life on Planets Circling Other Stars? 199
90 What Are Globular Clusters? 203
91 What Are Nebulas? . 204
92 What Is the Galaxy? 205
93 Where Is the Center of the Galaxy? 208
94 What Is the Doppler Effect? 211
95 Is the Galaxy Rotating? 214
96 Does Anything Reach Us from the Stars Besides Light? 215
97 What Is the Electromagnetic Spectrum? 219
98 How Did Radio Astronomy Develop? 222
99 What Are Pulsars? 224
100 What Are Black Holes? 228
101 What Is in Interstellar Dust Clouds? 230
102 What Is SETI? 233
103 Is the Galaxy the Entire Universe? 235
104 Are the Galaxies Moving? 238
105 Is There a Center of the Universe? 241
106 How Old Is the Universe? 242
107 What Are Quasars? 243
108 Can We See the Big Bang? 246
109 How Did the Big Bang Arise? 248
110 Will the Expansion of the Universe Continue Forever? 249
111 Is There Matter in the Universe We Can't See? 251
Index 253