1. Movements of the Earth

2. 3 basic motions of Earth Rotation:
Earth’s rotation is the rotation of the solid Earth around its own axis.
The earth rotates towards the East.

3. 3 basic motions of Earth Revolution:
The earth’s movement “orbit” around the Sun.
Earth travels around the Sun once every
365 ¼ days.

4. 3 basic motions of Earth Precession:
the movement of the rotational axis of a body
Earth’s will complete one circuit in approximately 25,700 years

5. Reasons for the Seasons

6. This is Saturday…9/22

7. Reasons for the Seasons
Earth’s Axis tilt:
Winter = Away
Spring = Neither
Summer = Towards
Fall = Neither

8. Earth’s Orbit
Aphelion -- the point on its orbit when the Earth is farthest from the sun
152,097,701 km (1.01 AU)
Perihelion -- the point on its orbit when the Earth is closest to the sun
147,098,074 km (0.98 AU)

10. Earth’s Axis Tilt and Sun Angle

11. Sun Angle and INTENSITY

12. Intensity and Earth’s Seasons

13. CLASSWORK/HOMEWORK Do objective’s 2.05 – 2.09
See book (p ) for all answers.

14. Science Tip of the Day
September 23, 2010
Fall officially started this morning at 3am. What did we “officially” call this?
Earth’s tilt (23.5o) causes seasons Explain (use your obj. notes) why.
- Include: Tilt, Sun Angle & Intensity
3. Did you ask your family why it’s warm in summer and cold in winter? What’d they say?

15. EQUINOX September 23
How does the sun appear anywhere on the globe today?

16. Solar System Unit of Measurement
The astronomical unit (AU ) is a unit of length based on the distance from the Earth to the Sun.
1 Astronomical Unit = 149 598 000 kilometers
(93 million miles).