1. Solar System Formation

2. Quick Write In this chapter, you will learn about the formation of the Solar System. Write down these questions and answer them in complete sentences. 1. What do all planets and stars begin as? 2. Describe condensation when planets form.

3. 1. How does SS formation begin? Gas and dust or interstellar cloud of dust and gas or a nebula (all same thing). 2. Most abundant gas in the universe? Hydrogen (H) 1st, and Helium (He) 2nd.

4. 4. Diagram of condensation. 5. How long does gravity take to condense a nebula? Starts slowly, speeds up as cloud becomes denser. 3. Do nebulas give off light? No, but stars near them or behind them cause them to glow.

5. Check for Understanding All stars and planets begin as what? Sketch a nebula beginning to condense into a planetesimal. Movie

6. 6. What two things come from nebulas? Stars and planets. 7. Planet formation? Starts with condensation of a cloud of dust and gas until a dense object forms (planetesimal).

7. 8. Diagram of solar system so far… 9. Then what? Planetesimals attract more dust and gas, and eventually become planets.

8. Check for Understanding Beginning with a nebula of dust and gas, the process of ______ will eventually cause planets and stars to form. Gravity or Condensation or Both Objects that form and eventually turn into planets are called _______. Nebular Clouds or Planetesimals

9. 10. Why few asteroid impacts now? Little dust and gas left after Earth, Moon and Sun have attracted it over 4.6 billion yrs. 11. Asteroids? Concentrated between Mars and Jupiter in the asteroid belt.

10. 12. Comets? Made of mostly ice. 13. Pieces of asteroids are called what? Approaching Earth = meteoroid. Burning up in Earth’s atmosphere = meteor. Impacts the surface of Earth = meteorite.

11. Check for Understanding Why are asteroid impacts on Earth and the Moon rare? Match the following: 1.Meteor a. burning up in Earth’s atmosphere 2.Meteoroid b. impacts surface of Earth 3.Meteorite c. approaching Earth Movie