Name____________________MOON PHASES

Introduction: The Moon, Earth’s natural satellite, appears to rise in the east and set in the west. As you know, this is a result of the Earth’s rotation from west to east. The Moon also appears to change shape during the month in a predictable pattern. The apparent shape change is due to the Moon’s ~28 day revolution around the Earth. In this lab you will see the Moon in several of its positions around the Earth and understand the reason for the apparent change in shape of the Moon. In addition, you will compare the Moon’s period of revolution around the Earth to the Earth’s period of revolution around the Sun. You will understand how the phases of the Moon relate to the position of the Moon relative to the Sun and Earth. You will also understand why we always see the same side of the Moon, and what rotation and revolution have to do with it.

Procedure A: Refer to Diagram 1 on the next page.

1. Lightly shade the half of the Moon that would be in darkness. (this is the side facing AWAY from the Sun).2. Lightly shade the half of the Moon that you CANNOT see from the EARTH (this is the side outside the Moon’s orbit).3. The Moon revolves around the Earth in the same direction that the Earth rotates. Use arrows to show the direction of revolution along the Moon’s orbit.4. Refer to the pictures below to correctly label that name of the phase for each position on diagram 1.5. Answer the questions.

Diagram 1

Sunlight

Sunlight

Sunlight

1

2

8

7

6

5

4

3

A

B

D

C

Questions: Refer to Diagram 1 to answer the following questions. Answer using the numbered position that the Moon is in.

1. _______________ During this phase the Moon is NOT visible from Earth.

2. _______________ During this phase the Moon appears to be COMPLETELY lighted from Earth.

3. _______________ During this phase the Moon appears to be half-lighted from Earth.

4. _______________ What is the motion of the Moon that causes it to have phases?

5. _______________ At what time of day would an observer have the new Moon cross their celestial

meridian? (position A)

6. _______________ At what time of day would the full Moon cross the observer’s celestial meridian?

7. _______________ At what time of day will the first quarter Moon be at the observer’s celestial

meridian?

8. _______________ At what time of day will the last quarter Moon be at the observer’s celestial

meridian?

9. _______________ In which direction will the Full Moon appear to rise?

10. _______________ In which direction will the First quarter Moon appear to set?

11. ______ & _______ At which positions would an observer on Earth experience Spring tides?

12. ______&________ At which positions would an observer on Earth experience Neap tides?

13. _______________ During this phase of the Moon an observer on Earth is able to view a Solar

Eclipse?

14. _______________ During this phase of the Moon an observer on Earth is able to view a Lunar

Eclipse?

15. In the space below, sketch the position of the Earth, Moon and Sun TODAY. You may have to look

this up on the internet or in the newspaper.

Procedure B: Refer to Diagrams 2 and 3 on the next page.

1. Each lab group will receive 8 Oreo cookies and a sheet of paper.2. Carefully separate your cookies so only ONE side/half has all the frosting and the other has NO frosting.

3. Use a plastic spoon/knife to scrap off the frosting from the first cookie to make a shape that resembles the

cookie shown below. This represents the moon in a Waxing Gibbous Phase.

4. Repeat step 3 with the other cookies; scraping the frosting into the shape of the remaining phases as seen

from Earth. You will have to create waxing and waning phases.

5. Place your cookie Moon phases on Diagram 3 in the correct positions. You must refer to Diagram 2 which

shows the Moon’s position in its orbit. Match up the positions on Diagram 3 to those on Diagram 2 and place

your cookies in the correct position. Remember to start at Position 1 and work in a counterclockwise motion

according to Diagram 3.

6. On Diagram 3 label each of the phases in order from Position 1 to Position 8

Diagram 2This diagram represents the Moon in its orbit around the Earth as viewed from the Earth’s North Pole. Position 1 represents a certain location of the Moon in its orbit.

Diagram 3 – The Earthlings View of the Moon (place your cookie moons here)

________________ ______________ ________________ ________________

Position 1 Position 2 Position 3 Position 4

________________ ______________ ________________ ________________

Position 5 Position 6 Position 7 Position 8

Questions:

1. How long is one cycle of Moon phases? ___________________

2. What is the average time (in days) between phases? __________________

3. Describe the processes that cause the Moon to appear in different phases to Earthlings.

4. What is the greatest number of Full-Moon phases that can occur over a one year period? __________

5. The small, white circle on each of the Moon’s in Diagram 2 represents the Impact Crater “Tycho”. Tycho

formed about 108 million years ago and is one of the youngest craters on the Moon. It was named after the

famous astronomer Tycho Brahe. Explain why this crater ALWAYS faces the Earth.

6. Referring to Diagram 2, when would an observer on Earth see an Eclipse?

Solar Eclipse _________; Position _____ Lunar Eclipse _________; Position _____

This diagram below shows the positions of the Moon and Sun at sunset during an evening in New York State.

Points A, B, C and D represent positions along the Western Horizon

.

7. At which position will the Moon be located the Following evening at Sunset? ( A B C D ) ?