1. The Earth-Moon Relationship

2. What is revolution? - When an object moves around another object
What is the revolution of the Earth?
-365 days

3. What is a rotation? When an object moves around it’s own axis.
What is the rotation of the Earth?
-24 hours

4. Just the Facts…. Earth Moon Diameter= 12,756km Rotation= 24 hours
Revolution around the sun =365 days
Moon
Diameter= 3,476km
Rotation= About 27 days and 8 hours
Revolution around Earth= 27 days and 8 hours
Average Distance from Earth 240,000 miles

5. The Moon does not make any light of its own, but just reflects sunlight down to earth.

6. Why do we only see one side of the moon?
…because the period of rotation for the moon is the same as its period of revolution.
Try it…….
Mark a ball (moon) with an “x” on it. This represents the near side of the moon.
Hold the ball out in front of you (sun) and rotate with the “moon” a complete circle.
Notice-the sun and moon both made a complete rotation

7. Now, rotate around with the “x” facing the same direction the entire time.
If this were the case, the moon would not be rotating, and we would see the far side of the moon!

8. Phases of the Moon
Within a month, the moon changes from a fully lit circle to a thin crescent and then back to a circle
Result of the changing position with respect to the Earth and the sun.
The different appearances of the moon due to its changing position are called phases

9. Waxing vs. Waning
Waxing-when the sunlit fraction we see from the Earth is getting LARGER.
Waning- when the sunlit fraction we see is getting SMALLER.

10. Like Clockwork… EARTH SUN 12 3 9 6 3. First Quarter Moon
4. Waxing Gibbous
Waxing Crescent 12 M M M
EARTH
EARTH
SUN M M 3
5. Full Moon 9 M M M M
1. New Moon 6
6. Waning Gibbous
8. Waning Crescent
7. Last Quarter

11. Phases of the Moon…

12. Let’s Try…
You are the Earth. Hold the pencil with the Styrofoam ball (moon).
Have another friend hold the light (sun) at 3:00.
Rotate your body with the moon and observe the various phases of the moon.

13. What’s an Eclipse?
Occurs when the shadow of one celestial body falls on another.
Lunar Eclipse- Earth comes between the sun and the moon and the shadow of the Earth falls on the moon. This happens every 6 months.

14. October 27,2004 Lunar Eclipse

15. Solar Eclipse- Happens when the moon comes between the Earth and the sun and the shadow of the moon falls on part of the Earth.

16. Movie of Solar Eclipses

17. Tides
The effect of gravity between the sun, moon and earth causes tides.
Tides are a result of the moon pulling the water toward it.
When the moon is on your side of the Earth, you have a high tide.
When the moon is on the opposite side of Earth, you have a low tide.