The Moon
Patterns of the motion of the Sun, Moon, and stars in the sky can be observed, described, and predicted.
Look up and what do you see?
During the day you see the Sun.
It glows bright in the daytime sky.
At night, you will see the twinkling of tiny stars.
The Sun and the stars have a regular pattern.
The Sun can be seen during the day, the stars at night.
What about the Moon?
What patterns does it have?
The Moon moves across the sky just like the Sun.
It moves across the sky just like the stars.
Unlike the Sun and stars, the way we see the Moon changes.
On some nights, you can see a big Moon hanging in the
night sky.
On other nights, only a part of the Moon can be seen.
The Moon really does not change shape.
The change in the way you see the Moon is all part of
its pattern.
The Moon repeats its pattern every 28 days.
You see the Moon full one night.
About seven days later, the Moon looks different.
No, it really has not changed shape.
It changes because it changes positions as it moves around
the Earth.
The half of the Moon that faces the Sun is always bright.
What changes is not how much is lit.
What changes is what part of the Moon we can see
from Earth.
Sometimes we cannot see the Moon.
We call this part of the pattern a new Moon.
Even then, half the Moon is lit by the Sun.
The Moon makes Earth’s oceans rise and fall.
The Moon pulls on the Earth with its gravity.
The Sun also plays a role.
The Sun has gravity too and pulls on the Earth.
This regular rise and fall is called the tide.
As the Earth rotates, gravity pulls in different places.
As a result, the water on Earth goes up and down.
The Moon has patterns and also causes patterns.
