1. LEQ: What are the two major motions of the Earth’s Moon?
Key Terms: rotation, revolution, lunar day, lunar year.

2. The Motions of the Moon
Open your textbooks to page 23 “Motions of the Moon”.
Like the Earth, the Moon moves through space in two ways:
Rotation
Revolution

3. The Moon’s Rotation
Like the Earth, the Moon rotates or spins on its axis.
Unlike the Earth, the Moon rotates on its axis much slower.
It takes 29.5 Earth days for the Moon to rotate once on its axis.
One “Moon day” is equal to 29.5 Earth Days.
View the Animation of the Moon's Rotation

4. The Moon’s Revolution
Like the Earth, the Moon revolves on its orbit around another object in space.
As you know the Earth revolves around the Sun, and it takes 1 year for the Earth to revolve once around the Sun.
The Moon revolves around the Earth.
It takes the moon 29.5 Earth days to revolve once around the Earth.
One “Moon” year is equal to 29.5 Earth days.

5. The Moon’s Rotation and Revolution.
As we saw, the Moon rotates once on its axis every 29.5 Earth days, and revolves once around the Earth once every 29.5 days.
So a Moon day and a Moon year are the same amount of time (29.5 Earth days).
View the animation of the Moon's Rotation and Revolution

6. The “Sides” of the Moon
This causes the same side of the Moon to always face the Earth. The side always facing the Earth is called the near side of the Moon, and the side never facing the Earth is called the far side of the moon.

7. Effects of the Moon’s Motions
In lessons 4 and 5, we will be discovering some of the different observable effects we experience on Earth including:
Phases of the Moon
Eclipses
Tides
Each of these effects is caused by:
The revolution of the Moon around the Earth.
The positions of the Moon, Earth, and Sun as the moon revolves around the Earth.