Contents -- Foreword -- Preface -- Acknowledgments -- About the Authors -- Introduction -- Section 1 -- 1 Is Earth Really "Round"? -- 2 Where Do People Live? -- 3 Falling Through the Earth -- 4 What Causes Night and Day? -- 5 The Two Rs -- 6 Where Did the Sun Go? -- Section 2 -- 7 Sunrise to Sunset -- 8 No Shadow -- 9 What's Moving? -- 10 Pizza Sun -- 11 How Far Away Is the Sun? -- 12 Sunspots -- 13 Shorter Days in Winter -- 14 Changing Constellations -- 15 Why Is It Warmer in Summer? -- Section 3 -- 16 Seeing the Moon -- 17 Sizing Up the Moon -- 18 Does the Moon Orbit the Earth? -- 19 Earth or Moon Shadow? -- 20 Moon Phase and Solar Eclipse -- 21 Comparing Eclipses -- 22 Moon Spin -- 23 Chinese Moon -- 24 Crescent Moon -- 25 How Long Is a Day on the Moon? -- 26 Does the Earth Go Through Phases? -- 27 Is the Moon Falling? -- Section 4 -- 28 What's Inside Our Solar System? -- 29 How Do Planets Orbit the Sun? -- 30 Is It a Planet or a Star? -- 31 Human Space Travel -- 32 Where Do You Find Gravity? -- 33 Gravity in Other Planetary Systems -- Section 5 -- 34 Shooting Star -- 35 Is the Sun a Star? -- 36 Where Are the Stars in Orion? -- 37 Which Is Bigger? -- 38 What Are Stars Made Of? -- 39 What Happens to Stars When They Die? -- 40 Do Stars Change? -- 41 Are We Made of Star Stuff? -- 42 Seeing Into the Past -- 43 What Is the Milk Way? -- 44 Expanding Universe -- 45 Is the Big Bang "Just a Theory"? -- Index.