2. Big Idea #1: Earth scientists use repeatable observations and testable ideas to understand and explain our planet.

3. Big Idea #2: Earth is 4.6 billion years old.

4. Big Idea #3: Earth is a complex system of interacting rock, water, air and life. (A SYSTEM OF SYSTEMS!)

5. Big Idea #4: Earth continuously changing.

6. Big Idea #5: Earth is the water planet.

7. Big Idea #6: Life evolves on a dynamic Earth and continuously modifies Earth.

8. Big Idea #7: Humans depend on Earth for resources.

9. Big Idea #8: Natural hazards pose risks to humans.

10. Big Idea #9: Humans significantly alter the Earth.

11. Q. What is the Age of Universe?

12. Q. What is the Age of Universe? A. About 13.7 billion years (Ga)

13. Q. How do we know this?

14. Q. What is the Age of Universe? A. About 13.7 billion years (Ga) Q. How do we know this? A. Intensity vs. Red shift of galaxies

15. Q. What is the Age of Universe? A. About 13.7 billion years (Ga) Q. How do we know this? A. Intensity vs. Red shift of galaxies Q. What is the Age of the Solar System?

16. Q. What is the Age of Universe? A. About 13.7 billion years (Ga) Q. How do we know this? A. Intensity vs. Red shift of galaxies Q. What is the Age of the Solar System? A. 4.56 Ga

17. Q. What is the Age of Universe? A. About 13.7 billion years (Ga) Q. How do we know this? A. Intensity vs. Red shift of galaxies Q. What is the Age of the Solar System? A. 4.56 Ga Q. How do we know this?

18. Q. What is the Age of Universe? A. About 13.7 billion years (Ga) Q. How do we know this? A. Intensity vs. Red shift of galaxies Q. What is the Age of the Solar System? A. 4.56 Ga Q. How do we know this? A. Radiometric dating of meteorites

19. Q. How large is the Milky Way?

20. Q. How large is the Milky Way? 80,000 light years

21. Q. What's a light year?

22. Q. How large is the Milky Way? 80,000 light years Q. What's a light year? (3 x 10 8 m/s x 365.25 days x 24 hr x 60 min x 60 s = about 9.5 x 10 15 m) So the Milky Way is 80,000 x 9.5 x 10 15 m = 7.6 x 10 20 m = 7.6 x 10 17 km = 5 x 10 17 mi 8 x 10 17 km = 800,000,000,000,000,000 km (I have no concept of how big this is)

23. …and the universe is a whole lot bigger than this.

27. Composition of Crust (%): WeightMolesVolume Oxygen47.261.793.8 Silicon28.221.0 0.9 Aluminum 8.2 6.4 0.5 Iron 5.1 1.9 0.4 Composition of Whole Earth (weight %): Iron35 Oxygen30 Silicon15 Magnesium13 Nickel 2.4 Geosphere

28. Hydrosphere: 96.5% in Oceans 3.5% in glaciers, groundwater ~0% in streams, lakes, atmosphere, biosphere 71% of Earth’s surface is covered with water. If Earth were a perfect sphere, it would be covered with 2.25 km of water.

29. Atmosphere:Composition: N 2 - 78.1% O 2 - 20.9% Ar - 0.93% H 2 O - 0.1% CO 2 - 0.039% (increasing) Ne - 0.0018%

30. Earth's magnetic field LOOKS LIKE there is a tilted, offset, wandering, bar magnet in its core. (But there isn’t!!) Fluid flow (convection) of liquid iron in Earth’s outer core creates the magnetic field.  Magnetohydrodynamo

31. The magnetosphere protects us from ionized particles of solar wind.

32. Biosphere: Extends from the seafloor and deep crust, to the tops of mountains and the atmosphere. 3 - 300 million species; ~1.5 million identified VERY significant geological agent (Ex: atmosphere, weathering)

33. Temperature 0ºC (~273 K) ~4000ºC ~6000ºC 3.62 Megabars 1 “bar” Pressure