Moon Phases
Objectives:
• Students will model the phases of the moon
• Students will be able to explain why the moon’s appearance changes
• Students will understand that only one side of the moon is ever visible
• Given a picture students will be able to identify the phase of the moon
Grade Level:
Eighth - Eleventh
Subject Areas:
Earth
Space Science
Timeline:
One class period
Background:
Teachers - Students should have a grasp on the following material. The sun is
the closest star to Earth. The sun rises and sets each day because the Earth
rotates on its axis. The sun is at the center of our solar system and all objects
including Earth orbit it. Planets can have orbiting objects called satellites or
moons. Earth’s satellite is the moon. There are additional objects in our solar
system including asteroids, comets, meteoroids, gas, and dust. Gravity holds our
solar system together and all objects in orbit around it.
Students – Know the background of the above elements.
Materials:
Six light stations (200 watt bulb)
Twelve Styrofoam balls
Twelve pencils
Moon phases' worksheet
Overhead projector
Transparencies
Lesson:
1. Vocabulary
Equator – The imaginary great circle around the earth's surface,
equidistant from the poles and perpendicular to the earth's axis of rotation.
It divides the earth into the Northern Hemisphere and the Southern
Hemisphere.
Latitude – The angular distance north or south of the earth's equator,
measured in degrees along a meridian, as on a map or globe.
Longitude – Angular distance on the earth's surface, measured east or
west from the prime meridian at Greenwich, England, to the meridian
passing through a position, expressed in degrees (or hours), minutes, and
seconds.
Polaris – A star of the second magnitude, at the end of the handle of the
Little Dipper and almost at the north celestial pole.
Axis – A straight line about which a body or geometric object rotates or
may be conceived to rotate.
Meridian – An imaginary great circle on the earth's surface passing
through the North and South geographic poles. All points on the same
meridian have the same longitude.
Celestial Equator – A great circle on the celestial sphere in the same
plane as the earth's equator.
Solstice – Either of two times of the year when the sun is at its greatest
distance from the celestial equator. The summer solstice in the Northern
Hemisphere occurs about June 21, when the sun is in the zenith at the
tropic of Cancer; the winter solstice occurs about December 21, when the
sun is over the tropic of Capricorn. The summer solstice is the longest day
of the year and the winter solstice is the shortest.
2. Moon facts:
• The Earth and moon are about 240,000 miles apart.
• The first person to step onto the moon’s surface was American astronaut
Neil Armstrong in 1969.
• The word month comes from the same root as Moon, because it is a
period of time that can be measured by the movement of the moon. Many
cultures follow a lunar calendar like Chinese, Hebrew and Islamic people.
• Christopher Columbus followed a lunar calendar and when some islanders
in Jamaica captured him he predicted an eclipse. This astonished his
captors so they freed him and his men immediately.
Question and Answer:
Q. Out of all the satellites in our solar system, what is the most well known?
A. The moon
Q. When you think of the Moon, does it always look the same in the sky?
A. The moon doesn’t always look the same in the sky because it goes through
phases.
Q. What are moon phases?
A. Phases are the appearance of the moon to change shapes throughout a
month.
Q. Why does the moon have phases?
A. At all times, the moon is half lit. However, the half that is lit isn’t always facing
us to see it. As the moon orbits the Earth we see more and more of the lit half.
At the moon’s half way point in its orbit, the moon appears to be entirely lit up.
Slowly we see less and less of the moon until we don’t see it at all (see attached
diagram).
3. Moon Phase Demonstration:
Invite the class up to demonstrate Moon phases with them. Use a 200 watt
bulb to represent the sun. Use the Styrofoam ball and pencil poked into it to
represent the moon. Your head will represent the moon. Get a volunteer to
show the class during the demonstration. First have the student place the
“moon” in front of them. The half of the moon that is lit up should be facing
the sun. Explain that this is a New moon phase. Slowly have them orbit the
Earth (their head). They will slowly see the right half of the moon light up. Be
sure to explain waxing and waning at this point. Waxing is when the moon is
in its first half of its orbit. The light appears to be lighting up the right half of
the moon we see from Earth. During waning phases (the second half of the
moon’s orbit), the light we see from Earth appears to be coming from the left
side of the moon (see attached diagram). Go through each moon phase as
follows: waxing crescent, 1st quarter, waxing gibbous, full moon, waning
gibbous, 3rd quarter, waning crescent.
4. At this point invite students to go to the six designated stations to practice
moon phases with their partners and complete their moon phases’
handout. Make sure students draw each moon phase and label each
phase. The teacher will go from station to station and help any student
who is struggling.
Extensions:
1. As an extension, the teacher could also include the concepts of seasons,
tides, and eclipses with this demonstration of using the sun (200 watt
bulb), Earth (student’s head), and moon (Styrofoam ball and pencil). This
could be utilized during a block lesson or another class period.
Evaluation:
• Students did model the phases of the moon
• Students did be able to explain why the moon’s appearance changes
• Students did understand that only one side of the moon is ever visible
• Given a picture students will be able to identify the phase of the moon
• As a test or quiz, the teacher could give the students a blank moon
phases' work sheet and require them to draw the moon phases and label
them correctly.
Resources:
www.ode.state.oh.us
www.hrw.com
Addendum
Moon Phases:
C
B
D
E
A
H
F
1. What is wrong with this picture?
G
2. What will the Moon look like from Earth?
A.
B.
C.
D.
E.
F.
G.
H.