1. Earth Moon Sun System How does the Earth Move? What causes seasons?
Why does the moon appear to change shape?

2. How does the Earth Move?
The Earth Moves in space in to major ways: Rotation and Revolution
Rotation is the spinning of an object on its axis
Revolution is the movement of one body around another body

3. Revolution of Earth The Earth is tilted on its axis about 23 degrees
This tilt is why the Earth has seasons as it revolves around the sun

4. Remember the direct and indirect sunlight from last unit
There are parts of the year that the north and south poles never get sunlight
During the winter, we have shorter days, and our place on Earth spends more time in the dark, away from the sun
During the summer, our days are longer, we spend more of the 24 hours of the day, on the lit side of the Earth.

5. Summer and Winter Solstice
The longest and shortest days of the year are called solstices
The winter solstice is in December and the summer solstice is in June

6. Motions of the Moon
The changing relative positions of the Sun, Earth, and moon cause the phases of the moon.
The Sun is always shining on half of the moon, just like Earth.
We do not see the entire lit portion each night
Sometimes the moon is highest in the sky during the day!

7. Eclipses
A solar eclipse happens when the moon passes between the Earth and the sun, blocking the sun
A lunar eclipse happens when the Earth passes between the sun and the moon
Why do we rarely see a lunar eclipse?
Why do we rarely see a solar eclipse?
Umbra – the very darkest part of the shadow during an eclipse
Penumbra – a larger part of the shadow that doesn’t block the light entirely