1. To the teacher:
This CPO Science PowerPoint presentation is designed to guide you through the process of presenting the lesson to your students. The presentation uses a 5-E teaching model: Engage, Explore, Explain, Elaborate, and Evaluate.
The PowerPoint Slide notes indicate where you may want to bring in various lesson elements such as quizzes, readings, investigations, animations, and practice materials. Additional science background information is provided in the slide notes where appropriate. You can view these notes by selecting “View,” then “Normal.” You will see the notes pane at the bottom of the PowerPoint workspace. Additionally, the slide notes are available as a separate document, accessible from the lesson home page.
The slides that follow are intended for classroom use.
About the slide notes:
The slide notes for this presentation are available in a separate document that you can print and look at while you use the slides. You can access the slide notes document from your teacher lesson home page.
Enjoy the lesson!

2. Mysterious Stonehenge
Stonehenge is a prehistoric monument completed 3,500 years ago in southwest England. It consists of a circle of giant stones (2.2 meters tall). The stones are precisely arranged so that on sunset on the shortest day of the year, the Sun appears to set over a particular stone.
Many archeologists believe that Stonehenge functioned as a kind of seasonal calendar as well as a festival site.
You can visit a replica of Stonehenge near Ingram, TX, just off of Highway 39.
Have you read about other prehistoric monument-calendars?
ENGAGE:
There are many interesting monuments around the globe which ancient people used to mark the passage of time. Students may be interested to learn more about Mexico’s Chichen Itza, the Pyramids of Giza in Egypt, New Mexico’s Fajada Butte, or Wyoming’s Medicine Wheel. An Internet keyword search on “Archeoastronomy” will dig up these sites and many others.

3. Time to investigate! Complete the lesson investigation:
Earth’s Seasons
What causes Earth’s seasons? Is it:
Changes in Earth’s distance from the Sun?
The tilt of Earth’s axis?
Both of these factors?
Something else?
EXPLORE:
Lead the lesson investigation: Earth’s Seasons. Before students begin their work, asks them to vote for one of the four possible answers to the question, “What causes Earth’s seasons?” Remind them to keep this question in mind as they work through the investigation. After the investigation, assign the student reading.

4. What causes day and night?
Earth rotates on its axis through one complete turn every 24 hours, marking off one day.
As Earth turns, part of the planet faces the Sun, and experiences daylight.
The opposite side of Earth faces away from the Sun, and experiences night.
EXPLAIN:
You can set up a simple demonstration of this concept with a lamp and a tennis ball in a semi-darkened room. As you spin the tennis ball in your fingers, students can see that each part of the ball spends some time bathed in light and some time in the shadow.

5. What causes the seasons?
As Earth revolves around the Sun, we experience seasons.
During summer in the Northern Hemisphere, the north end of Earth’s axial tilt is facing toward the Sun.
Six months later, the north end of the axial tilt is facing away from the Sun. The sunlight is more spread out and less intense. This brings winter to the Northern Hemisphere.
EXPLAIN:
Review with students what they learned through the investigation and their student reading: Earth’s axial tilt remains fixed as the planet revolves around the Sun. To reinforce this concept, watch the animation which can be accessed through the multimedia lesson home page.

6. Time for Practice! Complete the lesson practice activity:
Distance from Earth to the Sun
In the Northern Hemisphere, is Earth closest to the Sun in summer or in winter?
Did the answer surprise you?
What does this tell you about the reason for Earth’s seasons?
ELABORATE:
In this activity, students make a graph of the distance between Earth and Sun over the course of a year. They use this graph to answer the questions above.

7. Show what you know!
Try the lesson’s interactive quiz, or complete a quiz that your teacher can print out for you.
Hint:
You might want to review your lesson reading piece one more time before trying the quiz.
EVALUATE:
Print out the 10-question quiz for students to complete, or have students work individually at computers to complete the interactive quiz they can access from the multimedia lesson home page.