Reason for the Seasons

This activity engages learners to investigate the impact of Earth's tilt and the angle of solar insolation as the reason for seasons by doing a series of hands-on activities that include scale models. Students plot the path of the Sun's apparent movement across the sky on two days separated by three months of time.

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Nancy Moreno
et. al.
Baylor College of Medicine

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Teaching Tips

Teaching Tips

Measurements will have to be done at different times of the day, which may be problematic for courses that occur at a specific time of day.

One required material-- "clear plastic, dome-shaped lid" (as used to cover whipped toppings on coffee or frozen drinks)-- may be located through coffee shops or restaurant supply stores.

In step four when perihelion and aphelion are described, send the aphelion student to the other side of the orbit opposite to the perihelion student, not next to him/her. Then mention the dates of both.

Review what the activity is about before students go outside to do the hands-on activity.

Do activity early in the year and follow up multiple times in the school year.

For parts 1 and 2 of the activity, it may be valuable for the student to document what s/he saw in the model illustrating the distance between Earth and the Sun at perihelion and aphelion and illustrating tilt in the relationship to the Sun.

If you know that you will only be able to do the activity once, it would be good to have sample data (e.g. from previous years) and perhaps a video clip of prior efforts.

Potential follow-up data: How would the data collected compare to data collected at other latitudes?

To explore the sun angle for different dates and areas of the world, the USNO's Sun or Moon Altitude/Azimuth Table provides a way for you to obtain a table of the altitude and azimuth of the Sun or Moon during a specific day, at a time interval that you specify: