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Grade Level: K-4
Science Education Standards: Content Standard D -- Science and Technology: Objects in the Sky and Changes in the Earth and Sky
Short Description: This activity explores the relative size of the sun and Earth, as well as the distance between them.
Source: Sun-Earth Day
About this Activity
This activity explores the relative size of Sun and Earth as well as the distance between them.
What You'll Need
- copies of the Sun and Earth handout sheet (see next page)
- measuring tape
- a large room or a long hallway where you will be able to walk 65 feet in a straight line without many obstacles
- (optional) scissors
- (optional) 65 feet length of string
Measure 65 feet (the distance between Sun and Earth in the scale of our model) from where you will be doing this activity
and mark the distance for later reference. If you do not have a fixed location, we find it helpful to have a piece of string cut
to exactly 65 feet in length for you to use as a reference during the activity.
If you want your participants to guess the size of the Earth, you might want to keep the image of Earth out of sight by cutting off the top of the hand-out page along the dash line.
To Do and Notice
1) Show participants the image of the Sun. (This is a good opportunity to notice what the Sun's surface look like and to
point out that the Sun is not as featureless and uniformly bright as it might look to our eyes.) Ask participants to guess how big the Earth would be if the Sun is the size of this image.
2) Reveal the answer by showing the image of Earth. (Optional: you might want to let the participants cut out the Earth and the disc of the Sun instead of using the 2 sections of the handout sheet.) Ask participants to guess how far the model Earth should be from the model Sun. We suggest allowing participants to walk to where they think the distance should be. We find it helpful to tape the model Sun to a spot around eye-level at the starting point and have the
facilitator walk with the participants. The model Earth should be 65 feet away from the model Sun. Use the marker you placed earlier (or the cut piece of string) to guide you.
3) (Optional) At 65 feet away, look back towards the model Sun. Notice how big it looks to you at this distance. At this scale, the model Sun should be about the same size as the actual Sun would appear to us here on Earth. (It is always a good idea to remind participants not to look directly at the Sun.) Since this part requires a basic understanding of ratio and scale model, it might not be appropriate for all participants.
"Why does the Sun I see in the sky look different from this picture?" is a common question. The Sun image here was taken by a telescope that is mounted on a satellite in space (the TRACE mission to be exact). Besides being able to see farther than we can and without the clouds and Earth's atmosphere in the way, this telescope also looks at a different kind of light. The Sun gives off different kinds of energy, only part of that is in the form of visible light which we can see. The telescope that took this picture looks at the extreme ultraviolet (EUV) light coming from the Sun.
TRACE Education Resources: the Sun, its structure, and the satellite mission. http://trace.lmsal.com/Public/eduprodu.htm
Stanford Solar Center: About the Sun http://solar-center.stanford.edu/about/
Sun and Earth Images