2. Grab a piece of lined paper and your Unit 4 packets, and a BOOK
Let’s write test questions to begin our review
2 questions about the Earth’s Formation
2 questions about Earth’s layers

3. Day and Night
Summer and Winter
How would you adapt if the length of these changed?
How would that effect our society?

4. Earth’s Orientation
NOTES

5. EARTH’S REVOLUTION & ROTATION

7. Earth has 2 motions: rotation and revolution.
Rotation- the Earth completes one whole turn on its axis about every 24 hours

8. Earth’s axis is tilted 23.5°
Earth’s axis points toward Polaris, the North Star

11. Rate of Rotation
Earth makes on complete turn equal to a rotation of 360° approximately every 24 hours.
Every location on Earth’s surface rotates at a rate of 15° per hour; however, because of Earth’s spheroidal shape, the speed of rotation varies from point to point

13. Earth’s rotation makes the Sun appear to move across the sky everyday
Earth’s rotation makes the Sun appear to move across the sky everyday. It also causes the Sun’s apparent path across the sky to change throughout the year.

16. Revolution- the movement of Earth in its orbit around the Sun.

17. Question: How long does it take for the Earth to make one revolution around the Sun?

18. Rate of revolution
Earth makes one revolution around the Sun every days

19. Question:
This is the explanation for what occurrence every four years?

20. Constellations have been used for years as evidence of the Earth’s revolution.
Constellations which are visible on a winter evening are either in a different place in the summer night sky, or they are not visible at all

22. PATH AND RATE OF REVOLUTION
Direction
The direction of Earth’s revolution is the same as its direction of rotation: Counterclockwise when viewed from the North Pole, clockwise when viewed from the South Pole.

25. Distance from the Sun
Earth’s orbit is elliptical, therefore the distance the distance between Earth and the Sun changes.

26. Question:
Is the varying distance from the Sun a cause for the change of seasons?

27. Average distance the Earth is from the Sun = 150 million km (94 million miles)

28. At perihelion the Earth is closest to the Sun
At perihelion the Earth is closest to the Sun. Perihelion occurs at or around January 2nd.
At aphelion the Earth is the farthest away from the Sun. Aphelion occurs on or around July 4th.

30. Do you know a Leap Year Baby?

31. Quick Video….Earth’s Rotation

32. Effects of Revolution and Tilt
Effects of Earth’s revolution include the season and variation in the length of days and nights.

33. Earth’s tilt also has a profound effect on the seasons.
At any given time one hemisphere is pointed away from the Sun, while the other is pointed toward the Sun

35. Question:
How would changing the degree of the tilt effect life on the Earth?

37. Unit 4 Packets Page 1: PreAssessment Page 2: Latitude/Longitude
Page 3: Notes-Nebular Hyp/Earth’s layers
Page 4: Notes-Earth’s Shape/Magnetic F.
Page 5: Notes-Gravity
Page 6: Notes-Rotation & Revolution
Page 7: Equinox/Solstices
Page 8: Review Questions