1. The Earth’s Moon

3. Although the moon shines brightly at night, it does not give off its own light. We see the moon from Earth because sunlight is reflected off its surface.

4. The Face and Phases of the Moon
The face (the features on the surface of the Moon) does not change at all because the Moon’s rotation on its axis is the same length of time it takes to orbit the Earth.
The phase (how much and which side of the Moon is illuminated) of the Moon changes within one month period.

5. Key Vocabulary Orbit - The path of the Moon around the Earth.
Rotate - The Earth spins around, like a top, about its axis once each day.
Waning - Shrinking.
Waxing - Growing
Gibbous - Swollen on one side
Crescent – less than ½ the moon is visible.

6. What does that mean?
We are always looking at the same side of the Moon. We have never seen the opposite side from Earth.

7. Earth and the Moon in Space
Pulled by Earth’s gravity, the moon revolves around Earth in an ellipse-shaped orbit.
The Moon is farthest from the Earth at its apogee.
(405,000 to 407,000 km)
The Moon is closest to Earth at its perigee.
(360,000 to 370,000 km)

8. The Phase of the Moon
While the Earth is revolving around the Sun, the Moon is revolving around the Earth with a 29 ½ day period,
The phase of the Moon depends on the relative position between the Sun, the Earth, and the Moon.

9. Phases of the Moon

10. Names of the Phases of the Moon

11. New Moon
New Moon – The moon is between Earth and the sun. The moon can’t be seen because the sun is shining on the part that isn’t visible from the Earth.

12. Waxing Crescent
Waxing Crescent – The moon’s sunlit surface first appears as a growing crescent. A waxing moon seems to grow larger.

13. First Quarter
First Quarter – The moon looks like a half-circle. This phase is called the first quarter because the moon is a quarter of the way around the Earth.

14. Waxing Gibbous
Waxing Gibbous – The word gibbous comes from a word meaning “hump.” It is growing larger, swollen on one side!

15. Full Moon
Full Moon – About two weeks after a new moon, we see the entire sunlit half.

16. Waning Gibbous
Waning Gibbous - A waning moon appears to get smaller. It is swollen on one side, starting to shrink.

17. Third Quarter
Third (Last) Quarter – The moon is three-fourths of the way around Earth. Half of the moon will appear to be lit.

18. Waning Crescent
Waning Crescent – Only one-fourth of the moon appears to be lit. It is still getting smaller, or shrinking.

19. Formation of High Tides
The Moon’s gravity also pulls on the Earth. Because the oceans move more freely than the continents, this pull is more noticeable. The created bulges are the high tides (A).

20. Formation of Low Tides
The bulging water of the high tides also causes two areas of low tides (B) between the two areas of high tides (A) .