Objectives: The purpose of this lab is to get you to understand the phases of the moon and the relationships between the Sun, Earth, and Moon. I. Night and Day For the first section of this lab you will be pretending that your head is the Earth (the North Pole will be the top of your head, and the South Pole will be under your chin), and a light bulb will be the Sun. SETUP: (Yes you really need to do this -- but don't worry, it's fun, and easy!) You will need a fairly dark room (the darker the better!) with one bright lamp at about head level while you are standing or sitting. A single bright, uncovered light bulb works best. 1. Stand (or sit) facing the light bulb (Sun). The diagram below illustrates this setup as seen from above your head, so from above the North Pole of the Earth. Which of the lettered locations indicates the position of a person who lives on the end of your nose? abcdef 2. Which of the lettered locations indicates the position of a person who lives on your left ear? A B C D E F Not visible from this vantage point 3. Let's say you wanted to shade in the night side of Earth in the above diagram. Which of the numbered diagrams below shows the night side of Earth properly shaded in? 1 2 3 4 5 4. As seen from above the North Pole, the Earth rotates counter-clockwise. Refer to the lettered locations in the first diagram at the top. Indicate the places on your head where it is the following times of day: A. a B. b C. c D. d E. e noon sunset midnight sunrise no time -- this is the lightbulb, not a location on your head 5. What time of day would it be for a person that lives on the end of your nose when you are directly facing the light bulb? 12am midnight 3am 6am (sunrise) 9am 12pm noon 3pm 6pm (sunset) 9pm 6. Turn your body in place a quarter circle to the left (counterclockwise as viewed from the top down), but do not move the lightbulb. Now the light bulb should be off your right ear. Now what time is it for someone who lives on the end of your nose? 12am midnight 3am 6am (sunrise) 9am 12pm noon 3pm 6pm (sunset) 9pm 7. Turn your body another quarter turn to the left. Now the light bulb will be directly behind you. Now what time is it for someone who lives on the end of your nose? 12am midnight 3am 6am (sunrise) 9am 12pm noon 3pm 6pm (sunset) 9pm 8. Turn your body another quarter turn to the left. Now the light bulb will be off your left ear. Now what time is it for someone who lives on the end of your nose? 12am midnight 3am 6am (sunrise) 9am 12pm noon 3pm 6pm (sunset) 9pm II. Moon Phases Now we are going to examine the phases of the moon. Hold up a small ball to represent the moon at about head level, taking care not to block your view of the side of the ball facing you with your fingers. (Ideally, if you have access to a small styrofoam ball with a small hole in it, place this ball on the tip of an upright pen or pencil, so none of the ball's surface is blocked.) You will be holding the Moon out at arm'.

1. Objectives: The purpose of this lab is to get you to understand
the phases of the moon and the relationships between the Sun,
Earth, and Moon.
I. Night and Day
For the first section of this lab you will be pretending that your
head is the Earth (the North Pole will be the top of your head,
and the South Pole will be under your chin), and a light bulb
will be the Sun.
SETUP: (Yes you really need to do this -- but don't worry, it's
fun, and easy!) You will need a fairly dark room (the darker the
better!) with one bright lamp at about head level while you are
standing or sitting. A single bright, uncovered light bulb works
best.
1.
Stand (or sit) facing the light bulb (Sun). The diagram below
illustrates this setup as seen from above your head, so from
above the North Pole of the Earth. Which of the lettered
locations indicates the position of a person who lives on the end
of your nose?
abcdef
2.
Which of the lettered locations indicates the position of a
person who lives on your left ear?
A
B
C
D
E
F

2. Not visible from this vantage point
3.
Let's say you wanted to shade in the night side of Earth in the
above diagram. Which of the numbered diagrams below shows
the night side of Earth properly shaded in?
1
2
3
4
5
4.
As seen from above the North Pole, the Earth rotates counter-
clockwise. Refer to the lettered locations in the first diagram at
the top. Indicate the places on your head where it is the
following times of day:
A. a
B. b
C. c
D. d
E. e
noon
sunset
midnight
sunrise
no time -- this is the lightbulb, not a location on your head
5.
What time of day would it be for a person that lives on the end
of your nose when you are directly facing the light bulb?
12am midnight
3am
6am (sunrise)

3. 9am
12pm noon
3pm
6pm (sunset)
9pm
6.
Turn your body in place a quarter circle to the left
(counterclockwise as viewed from the top down), but do not
move the lightbulb. Now the light bulb should be off your right
ear. Now what time is it for someone who lives on the end of
your nose?
12am midnight
3am
6am (sunrise)
9am
12pm
noon
3pm
6pm (sunset)
9pm
7.
Turn your body another quarter turn to the left. Now the light
bulb will be directly behind you. Now what time is it for
someone who lives on the end of your nose?
12am midnight
3am
6am (sunrise)
9am
12pm
noon
3pm
6pm (sunset)

4. 9pm
8.
Turn your body another quarter turn to the left. Now the light
bulb will be off your left ear. Now what time is it for someone
who lives on the end of your nose?
12am midnight
3am
6am (sunrise)
9am
12pm
noon
3pm
6pm (sunset)
9pm
II. Moon Phases
Now we are going to examine the phases of the moon. Hold up a
small ball to represent the moon at about head level, taking care
not to block your view of the side of the ball facing you with
your fingers. (Ideally, if you have access to a small styrofoam
ball with a small hole in it, place this ball on the tip of an
upright pen or pencil, so none of the ball's surface is blocked.)
You will be holding the Moon out at arm's length and describing
its appearance at different points in its orbit. You will turn
around in place, keeping the moon at arm's length, to simulate
the orbit of the Moon (the ball) around Earth (you). The light
from the lightbulb will simulate sunlight. Stand as far away
from the lightbulb as possible, still staying within your
otherwise dark room, and make sure you can turn in place all
the way around without hitting anything with your outstretched
arm.
Below is a diagram, as seen from above your head (above the
Earth's North Pole), of the Moon's orbit around the Earth.

5. (Note: it is NOT drawn to scale.) In this diagram the Earth
rotates (spins) counter-clockwise in place, and the Moon orbits
the Earth in a counter-clockwise direction. Each of these
motions are shown with arrows. To represent that the sun is
very far away, the sunlight is represented as arrows coming in
from off the side of the diagram. You will notice eight different
numbered positions in the moon's orbit that we will be
examining in this exercise: Each location corresponds with a
different "phase" of the moon, as listed immediately below the
diagram.
9.
Copy the diagram above onto a blank piece of paper. Make it
nice and large so you have plenty of room to annotate it. Now
shade the "night" side of the Earth as seen from space high
above the North pole of the Earth, which is the perspective of
the diagram. Leave the "day" side of Earth blank. Which of the
lettered diagrams below shows how the Earth should be shaded?
Type the letter of your answer in the box here:
10.
Now label the "noon", "midnight", "sunrise", and "sunset"
points on the Earth in your diagram. This is a summary of what
you should have already figured out in the questions in Part I,
above.
Which of the lettered locations on the zoom-in diagram of Earth
below best represents each of those times?
Type one letter for each:
Noon:

6. Midnight:
Sunrise:
Sunset:
11.
Does the number of moons shown in the diagram correspond to
the number of moons that are orbiting the Earth in real life?
EXPLAIN in one or two sentences.
12.
In the diagram you have drawn on your paper, shade in the
"night" side of the MOON, leaving the day side blank, for each
of the numbered positions 1-8 of the moon in its orbit, as seen
from space above the Earth and Moon. Use the same perspective
as the diagram here (repeated from the top of this page), which
you should have previously copied onto your paper.
For each numbered circle, indicate which of the lettered options
below best matches how you shaded that circle, using the same
perspective as the diagram above.
Type one letter for each 1: 2: 3: 4: 5: 6: 7: 8:
Letters may be repeated or not used at all.
13.
Now comes the main part -- and the fun part! -- of this exercise,
where you will actually SEE the phases of the moon directly.
Using your head (Earth), ball (Moon), and light bulb (Sun)
model, you will simulate the Moon at different places in its
orbit and see what the phases look like directly. Starting with
the Moon at position 1, follow the Moon through one orbit
around the Earth by physically turning your body
counterclockwise (left) in place, and see what the moon looks
like at each position. (Make sure the shadow of your head

7. doesn't fall on the moon at position 5 -- that would be an
eclipse! That doesn't happen most months.) Here is a video clip
of a person demonstrating.
Shade in the dark portion of each circle so it matches the
appearance of the Moon as seen from the Earth at the eight
positions in the diagram.
For each circle, indicate which of the lettered options above (A
through N) best matches how you shaded that circle to represent
how you saw it in your physical simulation.
Type one letter for each 1: 2: 3: 4: 5: 6: 7: 8:
Letters may be repeated or not used at all.
14.
In a few sentences, describe how the apparent shape of the
moon changes during one orbit as seen from the Earth. Include
in your explanation: (a) Which side of the Moon (left or right)
is illuminated during the various stages? (b) How does the
apparent amount of illumination change over time? (c) Do the
physical size and shape of the Moon change during its orbit?
III: Times of Visibility
Now you will investigate what times of day the different phases
are visible from Earth. The diagram you have been creating on
paper will be your most useful tool for answering the questions
that follow. If you have not done it already, be sure you have
the day/night shadows drawn on Earth and Moon, the times of
day labeled at the different locations of Earth, and the names of
the different phases labeled on the diagram. A quick glance at
this diagram will tell you immediately what time of day (or
night) a given phase is high overhead. For the phase in question,

8. just look at the time of day it is on the location on Earth
directly under that phase. That is the time when that phase is
high overhead, because an observer standing at that location
would have to look nearly straight up to see that phase of the
moon. Several hours later, the moon will still be in that phase,
but the Earth (and the observer standing on it) will have rotated
counterclockwise, so the moon will not be high overhead for
that observer anymore. As viewed by that observer, the moon
will have appeared to move lower in the sky, on its way to
setting. For help visualizing this, or with any of the questions
that follow, experiment with the interactive animation at
http://astro.unl.edu/naap/lps/animations/lps.html. You can
advance the animation by pressing "start/pause animation", or
you can increment the animation one hour (or minute, or day) at
a time.
15.
Approximately how long does it take for the moon to complete
one orbit around the Earth? Pick one:
1 hour
1 day (24 hours)
1 week
1 month (a "moonth")
16.
How many phases will the Moon go through in that time?
17.
About how long does it take the Earth to spin once on its axis?
Pick one:
1 hour
1 day (24 hours)
1 week
1 month (a "moonth")
18.

9. How many phases will the Moon go through in that time? AND
How far will the moon have moved in its orbit? Explain in one
sentence or so.
19.
As viewed from Earth, what is the one PRIMARY reason that
the moon rises and sets in our sky? Explain in one sentence.
20.
Between one rising and subsequent setting, approximately how
long is the moon visible in the sky at a time? Pick one:
A) 1 hour
B) 12 hours
C) 24 hours
D) 1 week
E) 2 weeks
F) 1 month
21.
Now you will put together everything you have learned from the
previous sections in order to figure out when each moon phase
rises, sets, and transits through its highest point in the sky. This
is one of the biggest parts of this lab! It will take some time and
effort to figure it out. Be sure to use the hints at the beginning
of this section, and your answers to earlier questions. If you get
stuck, please consult your instructor ASAP. Keep in mind that
the moon rises and sets in our sky just like the sun does (as do
the stars and galaxies we can see from Earth!) and for the same
reason -- because the Earth spins on its axis. So the Moon is
visible for approximately 12 hours at a time on any given day,
just like the sun is. However, WHICH 12 hours it is visible
varies throughout the lunar cycle, as the moon is in different
parts in its orbit with respect to the Sun and Earth, and is
therefore often in a different part of the sky than the Sun.
At what time of the day would the New Moon be high overhead?

10. (Technically the moon is never directly overhead -- we are
looking for the time of day when the moon is highest in the sky.
For an observer in the northern hemisphere, it would be located
toward the South.) We call this time the transit time for the
Moon. At what time does the First Quarter Moon transit? The
Full Moon? The Third Quarter Moon?
To answer these questions, hold the moon ball out in your hand
at the position in question, say First Quarter. Then turn your
head to determine what time the Moon rises and sets for a
person who lives on the end of your nose (look at where the sun
is to figure out the time, referring to your diagram if necessary).
Record your answers to the transit questions in the table below,
then fill out the rest of the table by determining the rise and set
times of the four listed phases.
Your answer choices for all twelve boxes are "noon", "sunset",
"midnight", and "sunrise". Spelling counts!
Lunar Phase
Moon rise time
Moon transit time
Moon set time
First Quarter
Full Moon
Third Quarter

11. New Moon
22.
Could you see the First Quarter Moon at Sunrise?
yes
no
23.
Could you see the First Quarter Moon just before midnight?
yes
no
24.
Could you see the Third Quarter Moon at Sunset?
yes
no
25.
Could you see the Third Quarter Moon just after sunrise?
yes
no
IV: Eclipses
An eclipse can occur when the Sun, Earth, and Moon line up. A
lunar eclipse is when the Moon passes into the Earth's shadow,
and a solar eclipse is when the Moon's shadow falls on the
Earth. Still using your head to represent Earth, ball to represent
Moon, and lightbulb to represent Sun, act out both types of
eclipses. Use your direct observations of simulating these two
processes to answer the following four questions.

12. 26.
At what moon phase(s) can a lunar eclipse occur? Check all that
apply.
A) new moon
B) first quarter
C) full moon
D) third quarter
E) none of these
27.
At what phase(s) can a solar eclipse occur? Check all that
apply.
A) new moon
B) first quarter
C) full moon
D) third quarter
E) none of these
28.
Having simulated each of these types of eclipses with your
model Moon, which type was easier to make? Based on this,
which type do you think would be seen by more people on
Earth? Explain why.
29.
Why don't we see solar and lunar eclipses every month? Explain
in several sentences. Need a hint? Check here. or here.
V. Viewing the Earth from the Moon
Imagine for a moment that you are an astronaut standing on the
surface of the Moon and you can see the Earth from where you

13. are standing.
Refer to your diagram to help you visualize this situation for
the questions below.
30.
Would the Earth appear to have phases as viewed by an
astronaut on the Moon?
yes
no
31.
If an astronaut on the Moon currently observes a waxing
gibbous Earth, what would someone on Earth see when
observing the Moon? Describe in one sentence or so.
32.
If the Moon is in the first quarter phase as viewed from Earth,
in what phase would an astronaut on the Moon observe for
Earth?
A) new Earth
B) waxing crescent
C) first quarter
D) waxing gibbous
E) full Earth
F) waning gibbous
G) third quarter
H) waning crescent
33.
Develop an easy way to figure out the Earth's phase given the
lunar phase OR the lunar phase given the Earth's phase.
Describe your system below.
34.
If an observer on Earth is observing a total solar eclipse, what
would an astronaut on the side of the Moon facing Earth see?

14. Describe thoroughly in 1-2 sentences.
35.
If an observer on Earth is observing a lunar eclipse, what would
an astronaut on the side of the Moon facing Earth see? Describe
the whole event from start to finish, including everything the
astronaut on the Moon would see and how long it would last.
Aim for 2-3 full sentences.