TABLE OF CONTENTS 4 12 CHAPTER 1 Crashing into Earth CHAPTER 2 Shaping Earth CHAPTER 3 Tracking and Using Asteroids ACTIVITIES TOOLS Try This Glossary Index To Learn More 18 22 23 24 24
CHAPTER 1 CRASHING INTO EARTH Dinosaurs once ruled Earth Then about 66 million years ago a giant impact changed our planet What happened CHAPTER 1
A huge asteroid hit Earth Tons of dust filled the atmosphere It blocked the sun Earth was dark for several years The planet cooled Many plants and animals died This included the dinosaurs Earth would not warm again for decades CHAPTER 1
