Bell Work1. What causes the seasons to change on Earth?

2. How is the Earth positioned when the southern hemisphere is experiencing summer?

3. What is the vernal equinox different from the autumnal equinox, and how are they the same?

Lesson 4:Phases of the Moon

Earth in Space

Phases of the Moon

: different shapes of the moon seen from Earth: different shapes of the moon seen from Earth• phases:

• phases are caused by the amount of sunlight reflecting off of the Moon that we can see on Earth

• phases change because the positions of the Sun, the Earth, and the Moon change

• there are eight phases of the moon

Phases of the Moon1. New Moon

• the sunlit side of the Moon faces away from Earth and it is not visible

Phases of the Moon2. Waxing Crescent

• the portion of the visible Moon grows

Phases of the Moon3. First Quarter

• the right half of the sunlit side of the Moon is visible

Phases of the Moon4. Waxing Gibbous

• the portion of the visible Moon continues to grows

Phases of the Moon5. Full Moon

• the entire sunlit side of the Moon faces Earth

Phases of the Moon6. Waning Gibbous

• the portion of the visible Moon begins to shrink

Phases of the Moon7. Third Quarter

• the left half of the sunlit side of the Moon is visible

Phases of the Moon8. Waning Crescent

• the portion of the visible Moon continues to shrink

Review Questions1. What is are lunar phases?

2. What causes the moon to change phases?

3. Why is a new moon not visible from Earth?

4. During which phases does the moon appear to be a perfect half circle?

5. What is the difference between waxing and waning?

6. What is the difference between a crescent moon and a gibbous moon?

7. How is a full moon similar to a new moon, and how are they different?