Lunar Cycle
Goal: Identify the phases of the Moon, and
relate the phases to eclipses.
Memory Devices:
 White
on the right, growing bright!
 White
on the left, losing light!
Memory Devices:
 Wax
on – increasing light!
◦ Just as a candle wick is dipped in wax
and the candle wax increases the size of
the candle.
 Wane
off – decreasing light!
 Gibbous
– bulge
Memory Devices:
 New
 Full
Moon = Near the Sun
Moon = Far from Sun
 Remember,
YOU are on the EARTH
looking at the Moon.
The new moon
phase occurs when
the Moon is
between the Sun
and the Earth.
When this occurs,
there is a
possibility of having
a solar eclipse.
Solar eclipses do
not happen each
month because the
orbit of the Moon is
10o off from the
orbit of the Earth.
New Moon
The Moon
revolves around
the Earth.
Waxing
means to
increase in
size. This
refers to the lit
portion of the
Moon.
Crescent refers
to the shape.
Waxing Crescent
When the Moon
has gone one
fourth of the
way around
the Earth, it is
called the first
quarter.
From our point
of view, the
right half of
the Moon is lit.
First Quarter
The gibbous
phase looks like
a fat football.
The
word
gibbous
means
bulging.
During the
waxing gibbous
phase, the lit
side of the Moon
continues to
grow in size.
Waxing Gibbous
During the full
moon, we see
the light
reflecting from
the entire
surface of the
Moon facing
the Earth.
During this
phase, it is
possible to
have a lunar
eclipse.
Full Moon
Waning
means to
decrease in
size.
During the waning
phase of the Moon,
the lit portion
decreases in size.
The waning gibbous
occurs after the full
moon.
Waning Gibbous
The third
quarter has the
lit side on the
left.
The Moon is
three fourths
of the way
around its
orbit.
Third Quarter
The waning
crescent gets
smaller and
smaller, until
the Moon
completes its
orbit and
begins a new
cycle with
another new
moon.
Waning Crescent
The Moon moves
directly between the
Sun and Earth. The
Moon casts a
shadow on the
Earth; only occurs
with a new moon.
This does not occur
with every new
moon due to the
moon being 10o off
from the orbit of the
Earth.
Solar Eclipse
The Earth, Sun,
and Moon are
directly lined up
in the center. The
Earth casts a
shadow on the
Moon; only occurs
with a full moon.
This does not
occur with every
full moon due to
the Moon being
10o off from the
orbit of the Earth.
Lunar Eclipse
Memory Devices:
 White
on the right, growing bright!
 White
on the left, losing light!
Memory Devices:
 Wax
on – increasing light!
◦ Just as a candle wick is dipped in wax
and the candle wax increases the size of
the candle.
 Wane
off – decreasing light!
 Gibbous
– bulge
Memory Devices:
 New
 Full
Moon = Near the Sun
Moon = Far from Sun
 Remember,
YOU are on the EARTH
looking at the Moon.
First
Quarter
Review:
What phase is this? Be prepared to
Justify your answer.
New Moon
Waxing
Crescent
What phase?
What phase would be next?
Waning
Gibbous
Third
Quarter
What phase?
What phase would be next?
Full Moon
Waning
Gibbous
What phase?
What phase would be next?
Waxing
Crescent
First
Quarter
What phase?
What phase would be next?
Lunar
Eclipse
What type of eclipse could occur
during this phase?
First
Quarter
Waxing
Gibbous
What phase?
What phase would be next?
Waning
Crescent
New Moon
What phase?
What phase would be next?
What is different from our view on Earth?
A View From Outer Space
• Would you still be able
to label the phases
without seeing them?
• This type of question
and graphic is quite
common on
assessments.
A View From Outer Space
Moon Phase Graphic Organizer