Characteristics of the Sun
(Video)
Galileo: Sun-Centered System
(Video)
Observe Sunrise and Sunset
(Video)
Our star, the Sun, is an ordinary star. It is not particularly special compared to other stars in the universe; however, it is crucially important to us. As the massive energy source at the center of our solar system, the Sun is responsible for Earth's climate, weather, and life. In this lesson, students use observations, activities, and videos to learn basic facts about the Sun. Students also model the mechanics of day and night and use solar energy to make a tasty treat.
Three class periods
A few minutes each day throughout the year (optional)
Set up and try the model Earth demonstration to make sure that the lighting in the classroom will be effective. The light source should be placed in a central location with room for students to stand around it.
Mount all the Styrofoam balls on pencils — pierce the balls such that the pencil can act as an axis of rotation.
Familiarize yourself with the Characteristics of the Sun QuickTime Video.
Build and try a solar cooker to approximate the length of time it will take to cook the s'mores.
Place a marshmallow and a graham cracker in a plastic bag for each student.
1. Ask students to share what they know about the Sun. Record on the board their responses to the following questions:
2. Show the Observe Sunrise and Sunset QuickTime Video. Ask:
3. Discuss the different ways that people experience sunrise or sunset. For example, in some locations, people observe the Sun rise and set over land or water. In other locations, people observe the Sun rise and set behind tall buildings. Ask:
4. Have students use a compass to determine the direction of the Sun in the sky. If the Sun is shining through windows in the classroom, this activity may be done indoors. If there is no sunlight in the classroom, have students go outdoors. Record the time and direction of the Sun at hourly intervals to track the Sun's movement throughout the day. (Note: Remind students that they should never look directly at the Sun.) In the meantime, ask:
5. (Optional) To see how the Sun's position in the sky changes over the course of a year, have students judge the height of the Sun at the same time each day. By quickly glancing in the direction of the Sun, they should be able to categorize its position as low, medium, or high. Record the Sun's position on a calendar -- students should observe that the Sun is lower in the sky in winter and higher in summer. Note: Remind students that they should never look directly at the Sun.
6. Ask students to think about why the Sun appears to move through the sky the way that it does. Explain that some of the greatest thinkers in history had disagreements over whether the Sun orbits Earth or whether the Sun is still and Earth rotates.
7. For grades 3-5, show the Galileo: Sun-Centered System QuickTime Video. (K-2 teachers may want to view the video for background information.) Then discuss the following:
8. We now know that Earth (along with all the other planets in our solar system) orbits the Sun and that day and night are a result of Earth's rotation. Distribute the foam balls and stickers to have students model day and night -- do not worry about accurately modeling the tilt of Earth's axis. The light source, representing the Sun, should be placed in a central area with the students surrounding it. Have students place a sticker somewhere on their foam ball (the ball represents Earth and the sticker represents a place on Earth). As they rotate the ball (Earth spinning on its axis), they will see that sometimes the sticker is on the light side of the ball (daytime) and sometimes it is on the dark side (nighttime).
To show why the Sun appears to rise in the east and set in the west, have students place a second sticker to the left of the first sticker. Tell them to label the first sticker "E" for east and the second sticker "W" for west. Then have them rotate the balls counterclockwise (as viewed from above). Which dot receives light first?
9. Show the Characteristics of the Sun QuickTime Video once, all the way through. Replay the video and pause for discussion at important facts: The Sun is made of superheated gas; it is the center of our solar system; it is smaller than an average star, yet more than one million Earths could fit inside its volume; it has a temperature of about 3 million degrees Fahrenheit; it is about 93 million miles away from Earth. Students should be able to answer the following questions:
10. Discuss how we receive energy from the Sun in the form of light and the importance of the Sun for life on Earth. Ask:
11. Have students make a solar oven to harness the energy in sunlight. Break the class into groups of four and distribute the materials. Explain that they are going to use the Sun to cook s'mores. Discuss the following questions:
12. Show the Cooking Cookies with Solar Power QuickTime Video to demonstrate what they will be building - a cone-shaped solar cooker. Lead students through the assembly instructions, as follows:
For K-2:
For 3-5:
The Digital Library for Earth System Education (www.dlese.org) offers access to additional resources on this topic.