1. How Does Earth’s Orbit Cause Night and Day and Affect the Seasons?
Earth and Beyond
How Does Earth’s Orbit Cause Night and Day and Affect the Seasons?

2. Fast Fact
Sunrise from Space – Astronauts in space may see 16 sunrises and 16 sunsets everyday as they travel around Earth. In the Investigate, you’ll learn about movements of Earth and the moon.

3. Day and Night
Every day the sun appears to rise in the east. It seems to reach its highest point around noon , and set in the west. After a period of darkness, this process repeats itself.

4. Can You Explain It? Does the sun really rise and set?
No, it is the rotation of Earth that causes the appearance of a sunrise and sunset.

5. What Really Happens?
This cycle of day and night occurs because Earth rotates, or spins on its axis. When a place on Earth faces the sun, it is day in that place. When that place faces away from the sun, it is night.

6. Illuminated Globe Demo

7. Definitions You Need to Know
Sun – the star at the center of our solar system.
Rotate – to spin on an axis.
Axis – an imaginary line that passes through the North and South Poles.

8. Standard Times
Our system of time is based on Earth’s 24 hour cycle of daylight and darkness.
Because of Earth’s rotation, sunrise and sunset occur at different times for different places.

9. Work With Your Group
Each group will submit one response. Be sure to list everyone’s name on your assignment.
Explain the problem that time zones solved.
Explain how time zones work.

10. Trains Made a Difference
This wasn’t a big deal until the 1800’s when people started to travel long distances by trains.
To avoid confusion, standard times were developed.

11. Time Zones
It is 7:00 pm in California. What time is it in Alabama? What time is it in Florida?

12. Quick Review - Main Idea
Explain why officials needed to set up time zones in the late 1800’s.
People needed standard times to avoid confusion after they began to travel long distances on trains.

13. Insta-Lab
Sunrise, Sunset Demonstration – Use a flashlight and a ball to model day and night.
Each person will turn in a sheet of paper explaining how the movement of the Earth results in night and day. Use complete sentences. Also, draw a sketch to illustrate your explanation.

14. Why Does Earth Have Seasons?
Explain why Earth has seasons.
Earth’s axis is tilted.
What are the days called that have the most and the least hours of daylight?
Summer solstice; winter solstice

15. Seasons – Tilt Demonstration
Tilt the North Pole toward the sun, with North America on the sun side. This is our summer.
As the globe turns counterclockwise it becomes fall in North America. The days are shorter and it is not as warm.
As the globe continues to slide counterclockwise to the winter solstice, it is winter in North America.

16. Critical Thinking
When it is summer in the Northern Hemisphere, what season is it in the Southern Hemisphere? Explain why.
Why is it warmer in the summer than in the winter?

17. More Vocabulary Revolve – to travel in a path around another object.
Orbit – the path that Earth takes as it moves around the sun.
Equator – the imaginary line that divides Earth into the Northern and Southern Hemispheres.