EARTH-MOON-SUN-3DAYS
PHASESLesson Objectives:
By the end of this lesson, students should be able to:
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Identify each phase of the moon
Explain why we can see the phases of the moon
Overarching Questions:
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What is the universe, and what is Earth’s place in it?
Focus Questions:
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What are the predictable patterns caused by Earth’s movement in the solar system?
Lesson Questions:
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Why does the moon have different phases?
What are the different phases of the moon?
How long does it take the moon to complete one phase cycle?
Key Vocabulary:
crescent moon, full moon, gibbous moon, moon, new moon, orbit, phase, quarter moon,
waning, waxing
Phases
The moon waxes and wanes—appears to grow larger and smaller—during the course of a month.
The moon's size remains constant, but its changing position creates the different sunlit portions
we see on Earth. In this concept, you will learn about the different phases of the moon.
Getting to Know: Phases
The sun shines because it is producing energy. Why does the moon shine? The moon is
reflecting light from the sun. Even at night, we can see some of the light from the sun!
Moon Phases
The moon seems to change shape each night.
View Exploration
The Moon
The rotation of the moon around Earth produces the phases of the moon. The surface of the
Moon is covered in impact craters. The Moon revolves around the Earth in about 29 ½ days.
View Video Segment
View
Video Segment (7:33)
Inexplicable Effects of Lunar Phases, the Moon Impact Hastens The... The reason is unknown, but a full
moon usually means more activity for police officers and medi...
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Video Segment (1:12)
Phases of the Moon The moon orbits the Earth.
Phases
The moon waxes and wanes—appears to grow larger and smaller—during the course of a month.
The moon's size remains constant, but its changing position creates the different sunlit portions
we see on Earth. In this concept, you will learn about the different phases of the moon.
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Engage
Why Does the Moon Have Different Phases?
The changes in the appearance of the moon are called moon phases, and each is determined by
the moon’s position in relationship to Earth and the sun. The moon appears to shine because its
highly reflective surface, known as regolith, bounces the sun’s light back to Earth. Of course,
sunlight only reaches the half of the moon’s surface that is facing the sun. As the moon moves
around Earth, different portions of the moon’s sunlit surface are visible to us.
Phases
We see different phases of the moon because Earth, the moon, and the sun are always chainging
their positions in the sky.
View Animation
The Inconstant Moon
A full moon and a new moon are two phases of the moon.
View Exploration
What Are the Different Phases of the Moon?
A full moon is visible when Earth is between the sun and the moon. Sunlight bounces off the
highly reflective lunar soil and is visible from Earth. A new moon occurs when the moon is in
between Earth and the sun. At this point, the sun is shining directly on the moon, but it is shining
on the half we cannot see. When the moon appears as a half-circle in the sky, it is called a quarter
moon because we can see a quarter of the moon’s surface at that time. A crescent moon has a
thinner shape than the quarter moon, and a gibbous moon is thicker. The different shapes that
the moon appears to have during the course of a month are called “phases.” The lunar cycle
describes the order in which the moon’s phases will happen. It is the name given to the pattern of
change in the moon’s appearance. The lunar cycle includes every possible way the moon can
look. It is called a cycle because the pattern repeats itself.
How Long Does It take the Moon to Complete One Phase Cycle?
The moon orbits Earth in about 28 days, which is the basis of our calendar month. Because the
position of the moon changes constantly, the moon's appearance changes daily so that at times
you see the entire moon and at other times you do not see it at all.
Misconception: Some people think that the far side of the moon is always dark.
The far side of the moon is always facing away from Earth. Sometimes it is away from the sun
and dark; sometimes it is illuminated by the sun.
Phases
It takes about 28 days for the moon to go though all of its phases.
View Video Segment
Phases
The moon waxes and wanes—appears to grow larger and smaller—during the course of a month.
The moon's size remains constant, but its changing position creates the different sunlit portions
we see on Earth. In this concept, you will learn about the different phases of the moon.
View
Video Segment (1:56)
Moon Phases The moon rotates on its axis at the same rate that it orbits the Earth. The moon's
appearance c...
LAUNCH
Video Segment (1:12)
Phases of the Moon The moon orbits the Earth. Depending upon where it is in its rotation, it appears to
have a dif...
LAUNCH
Video Segment (3:52)
Phases of the Moon The phases of the Moon result from the change in position of the Earth, Moon and
Sun.
LAUNCH
Video Segment (4:34)
The Moon The moon is Earth's only natural satellite.
LAUNCH
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Reading Passage