Download Moon Phases - GWA 6th Grade

The BIG Idea
 Students will understand
that the appearance of the
moon changes in a
predictable cycle as it orbits
Earth and as Earth rotates on
its axis.
Objective 1: Explain patterns of changes in the
appearance of the moon as it orbits Earth.
Describe changes in the appearance of the moon
during a month.
 Identify the pattern of change in the moon’s
appearance
 Use observable evidence to explain the
movement of the moon around Earth in
relationship to Earth turning on its axis and the
position of the moon changing in the sky.
 Design an investigation, construct a chart, and
collect data depicting the phases of the moon

Objective 2: Demonstrate how the relative
positions of Earth, the moon, and the sun create
the appearance of the moon’s phases.

Identify the difference between the motion of an
object rotating on its axis and an object
revolving in orbit.

Compare how objects in the sky (the moon,
planets, stars) change in relative position over
the course of the day or night.

Model the movement and relative positions of
Earth, the moon, and the sun.
Must Know Vocabulary





Rotation – is the spinning of an object (i.e. planet)
around an imaginary center line.
Orbit – is the path that an object follows around a
central object.
Revolution – is to move in an orbit around another
object.
Axis – is an imaginary line through the middle of
an object, around which that object spins.
Reflection – the process of bouncing off.
Planetary Motion

Planets revolve in an orbit
around the Sun.

The Moon revolves in an orbit
our planet, Earth.

Day and night on Earth are
caused by Earth’s rotation on
its axis as it revolves around
the Sun.
The Moon
The Moon orbits (travels
around) Earth.
 The revolution of the Moon
around the Earth makes the
Moon appear as if it is changing
shape in the sky.
 From Earth we see the Moon
grow from a thin crescent to a
full disk (or full moon) and
then shrink back to a thin
crescent again before vanishing
for a few days.

Changes of the Moon
The different shapes that the
moon appears to have are
called the Moon’s phases.
 The Moon goes through eight
basic phases as it revolves
around Earth.
 The Moon completes an orbit
and a lunar cycle
approximately every 4
weeks.

Changes of the Moon
The moon is lit by sunlight
reflecting off it. That light
reaches Earth as moonlight.
 The lit part of the Moon
always points the way to the
Sun.
 The part of the moon facing
the sun is lit up. The part
facing away from the sun is in
darkness.

Changes of the Moon

The phases that you see
depends on how much of the
sunlit part of the moon you
can see.

The lit part you can see
depends on the alignment of
the Moon and Sun, and your
position on Earth.
The Moon

The phases we will be
discussing and observing are
as we see the Moon in the
Northern Hemisphere.

Did you know the countries
near the equator see the
crescent moon shaped like a
smile?
The Moon

Why are the phases different in each hemisphere?
The Moon orbits near the equator of the Earth.
 In the northern hemisphere, we're standing on the
opposite side of the globe from countries in the
southern hemisphere.
 We are essentially "upside down" from each other!
 Therefore, we see the Moon from a completely
different vantage point from each other.

The Moon
FOUR BASIC SHAPES
FULL
QUARTER
CRESCENT
GIBBOUS
The Moon passes through four major
phases during a cycle that repeats itself
every 29.5 days. The phases always
follow one another in the same order:
New moon
First quarter
Full moon
Third quarter
New Moon
The new moon occurs when the moon and
the sun are on the same side of Earth. The
moon is between the Sun and the Earth
and therefore lost in the glare of the sun.
We see the side which is not lit, so the
moon appears dark to us.
We can’t see a New Moon because the lit
side is facing directly away from the
Earth. The New Moon rises at dawn and
sets at sunset.
New Moon
New Moon
First Quarter Moon
The right half of the Moon appears lighted
and the left side of the Moon appears
dark. During the time between the New
Moon and the First Quarter Moon, the
part of the Moon that appears lighted gets
larger and larger every day, and will
continue to grow until the Full Moon.
First Quarter Moon
Full Moon
The lighted side of the Moon faces the
Earth. This means that the Earth, Sun,
and Moon are nearly in a straight line,
with the Earth in the middle. The Moon
that we see is very bright from the
sunlight reflecting off it.
Full Moon
Third (Last) Quarter Moon
Sometimes called Third Quarter. The left
half of the Moon appears lighted, and the
right side of the Moon appears
dark. During the time between the Full
Moon and the Last Quarter Moon, the part
of the Moon that appears lighted gets
smaller and smaller every day. It will
continue to shrink until the New Moon,
when the cycle starts all over again.
Third Quarter Moon
Comparing the First- and
Third-Quarter Moons
First-quarter Moon
Third-quarter Moon
There are also four other phases
of the Moon used.
Waxing Crescent Moon

"Waxing" means increasing, or growing
larger.

This Moon can be seen after the New
Moon, but before the First Quarter Moon.

The crescent will grow larger and larger
every day, until the Moon looks like the
First Quarter Moon.
http://btc.montana.edu/ceres/html/birthdayphases.html
Waxing Crescent Moon
Waxing Gibbous Moon
This Moon can be seen after the First
Quarter Moon, but before the Full
Moon. The amount of the Moon that we
can see will grow larger and larger every
day.
Waxing Gibbous Moon
Waning Gibbous Moon

"Waning" means decreasing, or getting
smaller.

This Moon can be seen after the Full
Moon, but before the Last Quarter
Moon. The amount of the Moon that we
can see will grow smaller and smaller
every day.
Waning Gibbous Moon
Waning Crescent Moon
This Moon can be seen after the Last
Quarter Moon and before the New
Moon. The crescent will grow smaller and
smaller every day, until the Moon looks
like the New Moon.
Waning Crescent Moon
The movie is an animated GIF created by Antonio Cidadao from a sequence of still images taken during March and April 1998.
Copyright Antonio Cidadao.
Let’s Review
Moon Phases!
It’s Just a Phase





Moonlight is reflected
sunlight.
Half the moon’s surface is
always reflecting light.
From Earth we see
different amounts of the
Moon’s lit surface.
The amount seen is
called a “phase.”
The visible light moves
(grows or shrinks) in a
right-to-left motion.
The Phases
New moon
 Waxing Crescent moon
 First Quarter moon
 Waxing Gibbous moon
 Full moon
 Waning Gibbous moon
 Third Quarter moon
 Waning Crescent moon
 New moon

last (third)quarter
waning Moon
moon orbit`s
earth
SUN
gibbous moon
crescent
earth
full moon
new moon
gibbous moon
crescent
waxing Moon
first quarter
Video
Go to YouTube.
 Search “The Universe: Phases of the
Moon”

Review Questions
How long does it take Earth’s Moon to
complete one lunar cycle?
2. What is a new Moon and what causes it?
3. What is the difference between a waxing
Moon and a waning Moon?
4. What is the difference between a
crescent Moon and a gibbous Moon?
5. Sketch the Moon’s appearance 1 week, 2
weeks, 3 weeks, and 4 weeks after the
new Moon.
1.