1. By: Mrs. Marnien and Mr. Huppert
Chapter 20
By: Mrs. Marnien and Mr. Huppert

2. Section 2 – Earth’s Moon
Unlike the Sun, the Moon does NOT emit its own light.
The moon seems to shine because it reflects light from the sun.

3. Earth’s Moon
1. Scientists hypothesize that the Moon formed from rock that was in a ring around Earth. The ring formed when Earth collided with an object about the size of Mars.

5. Earth’s Moon
2. Craters form from the impact of objects from space like meteors. Light-colored streaks called rays extend in all directions from some craters. 3. Craters on the moon are approximately 3.5 billion years old 4. On Earth, wind, water and plate tectonics have erased craters. The Moon has no wind, water or plate tectonics.

6. Earth’s Moon
5. Large, flat areas on the Moon are called Maria. They formed after most impacts on the Moon’s surface had stopped; lava flowed up through the Moon’s crust and solidified.

7. Earth’s Moon
5a. Highlands are light-colored areas on the Moon’s surface.

9. The Moon’s Motion
6. Gravity keeps the moon in orbit around the Earth. 7. It takes 27.3 days for the moon to orbit the Earth. 8. We always see the same side of the moon because the moon rotates at the same rate it revolves around the sun. The near side of the moon always faces the Earth Here is a video to explain:

11. Phases of the Moon
A phase is the lit part of the Moon or a planet that can be seen from Earth. 9. The motion of the moon around the Earth causes the phases. 10. A lunar cycle takes 29.5 days

12. Phases continued:
11. A waxing phase occurs when more and more of the moons near side is lit each night
12. A waning phase occurs when less and less of the moons near side is lit each night.
13. The moon does not give off its own light! It reflects sunlight.

14. Section 3 – Eclipses and Tides
When one object blocks light from another object a shadow results. 14. A solar eclipse occurs when the moons shadow appears on Earth’s surface 15. A solar eclipse will only occur during a new moon because the Earth, moon, and Sun are all lined up.

15. Eclipses Continued
16. A solar eclipse does not occur every month because the orbit of the moon is tilted.

16. Eclipses Continued:
16a. The darker central part of a shadow where light is totally blocked out is called the umbra. 16b. The lighter part of the shadow where light is partially blocked is called the penumbra.

17. Solar Eclipse
When the moon passes between Earth and the Sun, it casts a shadow on Earth.
During a solar eclipse the Moon’s shadow passes over Earth’s surface
A solar eclipse can occur ONLY during a NEW moon.

18. Lunar Eclipse
17. During a lunar eclipse, Earth casts a shadow on the Moon. A lunar eclipse can occur ONLY during a FULL moon phase.

19. Tides 19. The daily rise and fall of sea level is called a tide.
20. The main cause of tides is the gravitational pull of the Moon on Earth.
21. The sun has about half of the moons affect

20. Tides Continued: High tides occur at tidal bulges
Low tides occur between tidal bulges

21. Tides
22. During a Spring tide, Earth, the Sun and the Moon are positioned in a straight line (Full and new moons). At this time, high tides are higher than usual, and low tides are lower.

22. Tides
23. During a neap tide, Earth, the Sun and the Moon form a right angle. At this time, high tides are lower than usual, and low tides are higher.

23. Highest tidal range in the world. (Extreme high and low)
Bay of Fundy Canada
Highest tidal range in the world. (Extreme high and low)
Oceanographers attribute it to tidal resonance. The time it takes a large wave to go from the mouth of the bay to the inner shore and back is practically the same as the time from one high tide to the next.