2. Try This!  How did our solar system form?

3. Solar System Formation  Early universe – hot cloud of mostly hydrogen and helium  Gases clump to form nebula and gravity begins to concentrate mass  Stars are created through nuclear fusion - huge amounts of light and heat!

4. Solar System Origin (4.56 b.y.a.) ROTATING NEBULA THEORY Gravitational contraction and rotation of interstellar gas Planetary disk with central bulge Gravity causes sun to form Fusion and proto-sun Planets form from debris left

5. Evidence for Rotating Nebula Theory 1.The solar system is all the same age approx. 2.The planets all rotate in the same direction and on the same plane http://www.youtube.com/watch?v=xt9Bvc8s_d0 Hubble video 9 minutes

6. We Can Also Look and see solar systems forming elsewhere…. Close-up of “Protoplanets" in Orion

7. What’s in our solar system?

8. TERRESTRIAL PLANETS Density (mass/volume) = 4.0 - 5.5 g/cm 3 Earth is 149 597 871 km from the sun = 1 AU (astronomical unit) The Inner Planets: solid/rocky

9. The Asteroid Belt  Not all solar material formed planets!  Asteroids orbit between Mars and Jupiter  Source of majority of meteorites that fall to Earth  Most get pulled into Jupiter due to its large gravity

10. Stony meteorites  95 % of falls  They are called meteorites if the hit the Earth’s surface  Most burn up in the atmosphere and are called meteors or “shooting stars”

11. Meteoroid, Meteor, Meteorite… http://upload.wikimedia.org/wikipedia/commons/6/6 3/Meteoroid_meteor_meteorite.gif http://www.youtube.com/watch?v=4S6KatI7M3A

12. Captured a greater amount of the lighter materials of the initial solar cloud Density = 0.6 – 1.7 g/cm 3 The Gas Giant Planets

13. Kuiper Belt  Disk of debris at the edge of our Solar System  Pluto is a KB Object (sorry!)  Source of some comets

14. Pluto? considered a dwarf planet – not a true planet  Pluto ranges from 30 – 40 AU’s from the SUN (30 to 40 times farther from the SUN than Earth is!)  It has 3 moons  Frozen and rocky

15. Comets… frozen snowballs Dust tail – white, “smoke,” reflects sun. 600,000 to 6 million miles long tail – Solar UV breaks down CO gas, making them glow blue for of millions of miles

16.  The planets don’t ever all line up like this, but it shows their order and relative size  Earth is 1/1,000,000 the volume of the Sun

17. Try This! Planetary Preview – Complete the table Name of PlanetWhat I knowWhat I wonderWhat I learned

18. Jigsaw “The Universe and Its Stars” A. The origin of the universe B. Measuring distances in space C. The Birth of Stars, including our Sun D. Stars: Old Age, Death and New Life E. Galaxies and our Home: The Milky Way F. Dark Energy and the Expansion of the Universe