Ch. 6 Study Questions 1. What caused the giant cloud of gas and dust, that formed the solar system, to heat up? 2. Where did most of the water on Earth probably come from? 3. Why is most of the hydrogen and helium in the outer solar system? 4. What is the Kuiper Belt? 5. How did all the objects in the Kuiper Belt and the Oort Cloud probably get out there? 6. Where is the asteroid belt? 7. Why didn’t the asteroid belt clump up into a single big object. 8. Where did the craters in the Moon come from? 9. What are comets mostly made of? 10. What is the largest planet in the solar system?