2. The Earth is Born

3. 1. Was the moon closer or farther when Earth was younger?

4. 2. How old is the Earth?
4.5 billion years old

5. 3. If we imagine Earth’s total history to be just 24 hours long, how long ago did humans begin to walk the Earth?
30 seconds ago
If Earth was “born” at midnight, then humans were “born” at 11:59:30pm

6. 4. What is the name of the small, round, early planets?
Planetessimals

7. 5. When Earth first formed, what was Earth like?
A fiery ball of rock covered with lava

8. 6. What types of objects in the solar system give us information about the conditions under which the solid planets formed?
Meteorites

9. 7. What name do scientists give to Earth when the outer surface was completely molten?
A magma ocean

10. 8.During this time, when the Earth was liquid rock, what type of elements sank towards Earth’s center?
Heavier elements like iron

11. 9. Is the movement of the magnetic poles picking up speed or slowing down?

12. 10. Earth’s iron core creates a magnetic field which protects the planet from ___
Solar winds or CME’s

13. 11. What planet is believed to have once had a magnetic field that disappeared when the planet’s iron core cooled?
Mars

14. 12. How does the moon’s age compare to Earth’s age?
The moon is millions of years younger

15. 13. How did the moon form?
A large planetessimal collided with Earth.

16. 14. How quickly is the moon moving away from the Earth?
1.5 inches per year.

17. 15. How does the moon help stabilize Earth now?
It keeps Earth from wobbling and keeps our seasons steady.

18. Homework What did you know? What did you learn?
What are you confused about?

19. Earth

20. Physical Characteristics of Earth
Spherical shape
-satellite photos
-curved shadow on moon during a lunar eclipse.
-approaching ships “rise” over the horizon

21. Physical Characteristics of Earth
2. Rotation
-Earth spins on its axis (an imaginary vertical line) causing night and day.
-24 hours to rotate once on its axis -rotates 365 times in a year
–pendulum
Foucault’s Pendulum shows the Earth’s rotation as it swings

22. Draw Rotation

23. Draw Day and Night

24. Physical Characteristics of Earth
3. Magnetic Field
-Movement of liquid iron inside Earth and its rotation create a magnetic field.
-Helps protect Earth from harmful CME’s from the sun.

25. Draw Magnetic Field

26. Physical Characteristics of Earth
4. Revolution
-Earth’s yearly orbit around the sun. (365 ¼ days)
-Path is elliptical in shape.
Farthest away from sun in July
Closest to sun in January

27. Draw Revolution