Tracking the Sun: Observing the Path of the Sun Throughout the Year
Over the course of the school year, students will collect data about the sun's position at a specific time of day, resulting in creating an analemma (a figure 8 that shows the path of the sun).Recording should be at least weekly. Students will make predictions about the next position based on patterns they have noticed. Classroom discussion will be directed toward the concepts of earth's tilt and the effect of the sun's rays on the planet: warmth, seasons, amount of daylight per day, etc.
Students will gather data and analyze the patterns they see, making predictions for future data. Students will use critical thinking skills to determine how the path of the sun is related to the data they have collected, and how this affects our planet.
Students will use mapping and measuring skills to record the sun's shadow.
Vocabulary words : shadow, axis, planet, analemma, season, equinox, solstice, revolve, rotate
Context for Use
Description and Teaching Materials
To introduce this activity ask students what they have observed about the movement of the sun in the sky. Consider daily as well as seasonal changes they may have noticed. Have they had the sun shine in their eyes while at their desk? When was that? Was it every day? At the same time? Explain that during the year you will be recording data so you can think about the position of the sun and how it affects us. You will check the sun's position and mark where the tip of the arrow's shadow falls on the classroom floor with a sticky dot. Then students will mark the same spot on our classroom map with an X .(The teacher will need to do some measuring to keep this accurate, and show where to mark the placement on the transparency map) Students will keep the classroom map in their science notebook and use it all year. Remember to put the date next to each mark made on the map. Each time students mark the shadow, they will also be asked to make a prediction for the next measurement. The prediction can be marked with a P on the map.
In following lessons , mark the position of the shadow on the floor with a dot, measure and mark on student maps, make a prediction, then when several data points have been marked, discuss why students think they shadow has changed position, how is the temperature different (in general), what is happening outside (seasonal changes), and have students write about observations in their notebooks. Aslo during the course of the year be sure to discuss the concepts of revolution, rotation, seasons, planet tilt, direct versus indirect light and its effect on the earth. You can also discuss the equinox and solstice days, as markers of the special days each year when we have equal day and night, and when we have the longest/shortest days.
Teaching Notes and Tips
When students are marking their maps make sure they are aligned correctly. An initial discussion of directions and marking north on the maps is helpful for discussion purposes also. The dots on the floor will probably not last, that is why you are making a map. If you can make some type of mark that can stay on your floor it will make a bigger impression on the students as they make continuous recordings. Students may be surprised that the sun's shadow makes a figure 8, not just a line that gets longer and shorter. This is due to the planet's tilt and position as we revolve around the sun.
Students often think summer is warmer because we are closer to the sun. In reality, we are further from the sun at the northern latitudes during summer. (Though the difference in distance is slight.) It is the directness of light because of our tilt toward the sun that warms our earth.
When we change our clocks due to Daylight Savings Time, there will be a corresponding change in the location of the sunspot. If you can take your data an hour earlier you will continue your pattern. Otherwise, you will need to discuss why there is such a big change in the sun's position after the time changes.