Updated Klein ISD, 2008

Rotation What is the daily movement of the Earth called?

The moon also rotates. If we always see the same side, why does the moon look different during the month?

The moon rotates at the same rate it revolves.

Because of this, we never see the far side of the moon.

The new moon occurs when the moon is between the Earth

and the sun.

During a new moon the side of the moon facing the Earth is not reflecting any sunlight. It appears as if there is no moon

at all.

The new moon is the beginning of the cycle of lunar

phases.

As the moon continues to travel along its orbit, we are able to

see only a small portion of the moon. This is called a crescent

moon.

Waxing means growing. Since the moon appears to be growing

this phase is called waxing

crescent.

As the moon continues to revolve around the Earth, we are able to view more of the

lighted side of the moon.

The next lunar phase is the first quarter moon.

Why is it called a quarter moon when it appears that we

are seeing half the moon?

Remember we are not seeing the dark side of the moon.

In essence we are only seeing half of the lighted half of the

moon.

Half of a half is a quarter!

1/2 X 1/2 = 1/4

The word gibbous means swollen on one side.

As the moon begins to “grow” into a full circle it is called a

waxing gibbous.

Do you remember what the word waxing meant?

Waxing means growing!

The full moon is the next lunar phase.

When a full moon occurs, the Earth is between the sun and

the moon.

During a full moon we see a complete circle in the sky,

even though only half of the sphere is reflecting sunlight.

Swollen on one side. What does gibbous mean? The next phase is called waning gibbous.

Waning means shrinking. During the waning gibbous phase the moon seems to be

disappearing!

The last quarter is the next lunar phase.

Why is it called a quarter? Remember we are seeing half of a half or one quarter of the

whole moon!

the first quarter moon? How is the last quarter moon different from ...

They are mirror images of each other.

The last phase is the waning crescent.

What does waning mean? Waning means shrinking. You are seeing a smaller portion of the moon.

What do you think the next phase is?

The new moon!

The complete lunar cycle takes about 29 days.

What is a blue moon?When two full moons occur in the same month, the second

full moon is called a blue moon.

The moon is not really blue. Two full moons in one month

rarely appear.