1. JOURNAL #17 – THE SOLAR SYSTEM 1.What is the order of the planets from the Sun outward? 2.If during a solar eclipse the moon must be between the Sun and a planet, which planets can have a solar eclipse? 3.What is the difference between a meteor, meteoroid and meteorite?

2. Objective : Understanding the structure of the solar system and what it is composed of. THE SOLAR SYSTEM

3. MODELS OF THE SOLAR SYSTEM Geocentric Model Earth centered Sun, moon and stars revolve around the Earth Proposed by early Greek scientists

4. MODELS OF THE SOLAR SYSTEM Heliocentric Model Sun centered Moon revolves around Earth but all planets revolve around the sun Proposed by Nicholas Copernicus in 1543

5. HOW DID IT FORM? Solar System Formation Large cloud of ice, gas and dust contracted Gravity pulled matter inward forming the sun Planets formed from remaining materials 4.6 billion years ago

6. WHEN DID THE SUN BECOME A STAR? The sun became a star when Its core temperature reached 10 million degrees Celsius

7. NUCLEAR FUSION Nuclear Fusion Atoms with low mass combine to form heavier elements Help in creation of planets

8. THE PLANETS Rocky or Terrestrial Planets Inner planets Rocky in texture Mercury, Venus, Earth, Mars

9. MERCURY Mercury Closest planet to the sun

10. VENUS Venus Similar to Earth Sun rises in the West and sets in the East Rotates in the opposite direction of Earth Active lava flows

11. EARTH Earth Sustainable for life: key is liquid water Weather patterns Distance from sun keeps us warm enough to prevent us from freezing and cool enough to keep us from boiling

12. MARS Mars The red planet Most studied planet Thin atmosphere and distance from sun make it cold Dry river beds evidence of water on Mars in past Two polar ice caps: frozen water, frozen carbon dioxide

13. THE PLANETS Gas or Jovian Planets Outer planets Composed of gases Jupiter, Saturn, Uranus, Neptune

14. JUPITER Jupiter Made of helium and hydrogen Clouds of ammonia and methane Great Red Spot: long lasting storm Radiates more heat into solar system than it takes in from the Sun

15. SATURN Saturn Second largest planet Gives off more heat than taken in by the sun Still forming Rings of Saturn: largest rings of the gas giants; made of icy particles

16. URANUS Uranus Through a telescope it looks like a blue-green disk Smaller gas planet Tipped on side; axis is almost 90 degrees Reason: possibly got hit by an object large than itself

17. NEPTUNE Neptune Atmosphere contains a visible belt of clouds Great Dark Spot: similar to Jupiter’s Great Red Spot (long lasting storm)

18. PLANET ORBITS All planets orbits are elliptical Discovered by Johannes Kepler in 1600’s (Kepler’s Three Laws of Planetary Motion)

19. CELESTIAL BODIES Comet Large “dirty snowball” that circles the sun Composed of frozen gases, ice, cosmic dust particles Loosely packed together Originated: cold, outer solar system Comet Tails: created when they pass close to the sun, the solar radiation melts the ice and gives off gas and dust Halley’s Comet took 76 years to orbit

20. CELESTIAL BODIES Oort Cloud Large collection of comets surrounding the solar system Located beyond the orbit of Pluto

21. CELESTIAL BODIES MeteoroidMeteorMeteorite Piece of rock moving through space Meteoroid that burns up in Earth’s atmosphere Meteor that strikes Earth’s surface **Meteors are commonly called Shooting Stars**

22. CELESTIAL BODIES Asteroid Pieces of rock in space smaller than a planet Asteroid Belt is between Mars and Jupiter Suspected formation: strong gravitational pull from Jupiter kept a planet from forming Kupier Belt: hundreds of icy objects beyond the orbit of Neptune