1. Earth and Sun Relationship
Day 4---

2. Let’s Start with the Earth
We have day and night because the Earth rotates on its axis
Axis—imaginary line that goes through the center of the earth

3. Now Let’s Add the Sun The Earth revolves around the sun in an orbit
One revolution takes Earth one year

4. Earth Moves Through Space in Two Major Ways1. 2.

5. What does this have to do with Seasons?
The Earth’s axis is tilted—the tilt gives us the seasons
Look at the globe
Hemispheres with direct rays will be warmer than areas hit by indirect rays
Think about the equator
Think about the poles
Since the earth is making a revolution around the sun, different hemispheres get more or less direct rays at different times of the year—causing the seasons
Points to the star Polaris—the Earth is never upside down

6. Which hemisphere is receiving more direct rays?
Which hemisphere is receiving more indirect rays?
What season do you think it is for the Northern Hemisphere?
Southern Hemisphere?
Northern Hemisphere is in Summer and South is in Winter
The seasons are reversed in the North and South

7. The reason for the seasons is the angle at which the sun’s rays strike the earth, caused by the tilt of the Earth on its axis. The tilt of the Earth also causes the change in the number of daylight hours experienced throughout the year

8. Equinox vs. Solstice
Look at the left picture—which two earths show an equinox? What seasons would there be an equinox and why?
Answer: Direct rays are hitting everywhere, no one hemisphere is receiving more rays
Look at the left picture—which two earths show a solstice? What are the months that correspond with each

9. Let’s Draw a Diagram Together!