Calculating the declination of the sun for elementary students
Summary
In the school courtyard, students will measure the apparent path of the sun across the sky using a toilet plunger. Students will then generate questions as to why the sun appears to move, and what is really happening in the process. We will then construct paper astrolabes, and measure the angle of the sun compared to earth (its declination). This can lead into a discussion of the seasons.
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Learning Goals
Goals:
Students will describe the pattern of the sun as it appears to move across the sky.
Students will draw the declination of the sun for the current day in their science notebooks.
Students will compare observations of the declination of the sun from one season to the other.
Concepts:
The sun's path across the sky changes from season to season.
The sun's path can be predicted and measured, using simple tools.
Vocabulary:
Astrolabe
Angle
Declination
Revolution
Rotation
Students will describe the pattern of the sun as it appears to move across the sky.
Students will draw the declination of the sun for the current day in their science notebooks.
Students will compare observations of the declination of the sun from one season to the other.
Concepts:
The sun's path across the sky changes from season to season.
The sun's path can be predicted and measured, using simple tools.
Vocabulary:
Astrolabe
Angle
Declination
Revolution
Rotation
Context for Use
This is a field exercise for third graders in a self-contained classroom. The entire activity, including the field exercises and follow up work should take four 55 minute class periods. It requires a large sheet of poster paper and a toilet plunger for each group of students, and an astrolabe pattern for each student (printed pattern, straw, string, bead and cardstock). Students should have been exposed to the concept of angles prior to this activity. It would be easily adaptable to other levels and group sizes. Teachers should have access to the KARE 11/Jeffers Foundation weather calendar to compare data.
Description and Teaching Materials
1- Day 1, part 1-Take a toilet plunger and posterboard outside first thing in the morning. Place it on the ground with heavy rocks or paperweights to hold it in place. Set the plunger on the south side of the paper, and mark where the top of the plunger's shadow falls. Go back inside, and ask the student to predict how they think the shadow will change as the day progresses. As the day progresses, preferably every 60 minutes, go back out to the paper and mark movement of the shadow. After the final observation, have students compare their predictions with the actual pattern of apparent movement, and discuss the reasons why the sun appears to move and which way the shadows fall.
2- Day 1, part 2- Watch the united streaming video on the sun and stars. Discuss: if the sun doesn't move, why does it seem like it is moving to us?
3- Day 2, make paper astrolabes (pattern available here: http://cse.ssl.berkeley.edu/AtHomeAstronomy/activity_07.html), and go outside to practice measuring the angle of the sun and where it is in the sky. DO NOT LOOK DIRECTLY AT THE SUN. Practice also measuring on a compass where the sun is in the sky using N, NW, W, SW, S, SE, E, NE
4- Day 3, part 1- Go outside first thing in the morning, observe and measure where the sun is in the sky, and how high. Go back outside once each hour to take readings. Record the data in a data table in science notebooks.
5- Day 3, part 2- Students will take a wonder wander (using their science notebooks to write observations and questions while walking around the school) looking for evidence that the sun heats the earth.
6- Day 4- Compare data from plunger sundial, astrolabes, video, and wonder wander to determine patterns in how the sun moves across the sky. Compare declination angles with the weather calendar provided by KARE 11.
7- Later in the year, perhaps once a month, take students outside with their astrolabes to check the declination of the sun. Compare results with the weather calendar.
2- Day 1, part 2- Watch the united streaming video on the sun and stars. Discuss: if the sun doesn't move, why does it seem like it is moving to us?
3- Day 2, make paper astrolabes (pattern available here: http://cse.ssl.berkeley.edu/AtHomeAstronomy/activity_07.html), and go outside to practice measuring the angle of the sun and where it is in the sky. DO NOT LOOK DIRECTLY AT THE SUN. Practice also measuring on a compass where the sun is in the sky using N, NW, W, SW, S, SE, E, NE
4- Day 3, part 1- Go outside first thing in the morning, observe and measure where the sun is in the sky, and how high. Go back outside once each hour to take readings. Record the data in a data table in science notebooks.
5- Day 3, part 2- Students will take a wonder wander (using their science notebooks to write observations and questions while walking around the school) looking for evidence that the sun heats the earth.
6- Day 4- Compare data from plunger sundial, astrolabes, video, and wonder wander to determine patterns in how the sun moves across the sky. Compare declination angles with the weather calendar provided by KARE 11.
7- Later in the year, perhaps once a month, take students outside with their astrolabes to check the declination of the sun. Compare results with the weather calendar.
Teaching Notes and Tips
Make sure to try the astrolabe activity yourself before attempting it with students. It can be tricky to find the correct angle to hold it, and you need to be able to explain it clearly. Do not, at any time, look directly at the sun. For tips, look here: http://tinyurl.com/lv56bb
Assessment
Student notebooks will be assessed using a checklist.
Standards
3.3.3.1.1 Describe daily and seasonal changes in position of sun and compare observations.