Chapter 25 The Solar System 792
25.1 Exploring the Solar System 794
25.2 The Earth-Moon System 800
25.3 The Inner Solar System 807
25.4 The Outer Solar System 814
Concepts in Action
Comets and Meteoroids 820
25.5 The Origin of the Solar System 822
Chapter 26 Exploring the Universe 830
26.1 The Sun 832
26.2 Stars 838
26.3 Life Cycles of Stars 844
26.4 Groups of Stars 850
Concepts in Action
Scale of the Universe 854
26.5 The Expanding Universe 856
Skills Handbook 868
Science Skills 868
Reading and Study Skills 874
Math Skills 876
21st Century Skills 883
Map Skills 884
Appendices 893
Appendix A: SI Units 893
Appendix B: Using a Laboratory Balance 894
Appendix C: The Chemical Elements 895
Appendix D: Identifying Common Minerals 896
Appendix E: United States Physical Map 898
Appendix F: Weather Map 900
Appendix G: Relative Humidity Chart 901
Appendix H: Star Charts 902
Appendix I: Problem Bank 904
Appendix J: Selected Answers 906
Glossary 907
Spanish Glossary 922
Index 941
Acknowledgments 954