Seasons by the Sun

Meri-Lyn Stark

Understanding the Sun has challenged people since ancient times. Mythology from the Greek, Inuit, and Inca cultures attempted to explain the daily appearance and nightly disappearance of the Sun by relating it to a chariot being chased across the sky. While people no longer believe the Sun is a chariot racing across the sky, teachers are still challenged to help children develop accurate understandings about the Sun and the “reasons” for the seasons. This month’s books and activities can build a foundation for learning about this topic.

This Month’s Trade Books

Sunshine Makes the Seasons
By Franklyn M. Branley.
Illustrated by Michael Rex.
HarperCollins Publishers. 2005.
ISBN 0060592036.

Synopsis

Sunshine Makes the Seasons describes how the Earth’s tilt on its axis and position around the Sun helps produce the seasonal changes we experience on Earth. The book provides illustrations and diagrams along with a narrative text that walks the reader through an experiment that models this concept.

Arctic Lights Arctic Nights
By Debbie S. Miller.
Illustrated by Jon Van Zyle.
Walker Publishing. 2003.
ISBN 0-8027-8857-2.

Synopsis

Arctic Lights Arctic Nights describes the activities of animals near Fairbanks, Alaska, as they experience some of the world’s greatest temperature extremes and light variations throughout the year. During the summer, the northern hemisphere is tilted toward the Sun. In Fairbanks, Alaska, this means there are nearly 22 hours of sunlight on the longest day of the year. This book allows the reader to explore other interesting facts about this location throughout the course of the year.

Curricular Connections

These books and their accompanying activities relate to National Science Education Standard (NSES) Content Standard D: Earth and Space Science—specifically, Objects in the Sky and Changes in Earth and Sky.

In the K–3 activity, students trace and measure shadows seasonally (one time each in fall, winter, and spring), recording their observations and reflecting on those observations with their teacher, repeating the same activity each observation period. As they compare previous date’s observations to their new observations, students can begin to make connections to patterns of movement in the sky and other observations, a learning goal identified in the NSES (NRC 1996).

In the activity for students in grades 4–6, the focus is on understanding the relationships between Earth and the Sun in the Solar System and how these celestial objects relate to the seasons, a learning goal identified in the Earth and Space Science Content Standard for grades 5–8: Earth in the Solar System.

Using the book Arctic Lights Arctic Nights, students note the differences in sunset and sunrise times over the course of the year in Fairbanks, Alaska, then discuss with their teacher how the length of daylight relates to the seasons.

Trade Book–Inspired Investigations

For Grades K–3: Shadow Studies

Begin this activity by reading aloud Sunshine Makes the Seasons and encouraging students to discuss what types of changes they notice throughout the year. Discuss with students that shadows can tell them about where the Sun is in the sky.

Explain to students that they are going to be measuring an object’s shadow throughout the year (once each in fall, winter, and spring). Ideal times would be any of the days around the September and March equinoxes and the December solstice. Students should never look directly at the Sun as it can damage their eyes.

Provide each student a science journal with room for recording simple data (the date, time, and measurement data) and drawing a seasonal picture.

Once students have the guidelines, the class should venture outside at a specified time in the morning (9:00 a.m. works well) and choose an object. Students will trace this object’s shadow with chalk. Students can then measure the length of this object’s shadow using age-appropriate tools and nonstandard, standard, or metric measurements. While measuring the shadow, the teacher can focus the students on such questions as, “Is there a relationship between the position of the Sun (i.e., compass direction) and where the shadow appears?”

Each student will record the length of the shadow for the specified day and time. After measuring and recording data, encourage children to notice their natural surroundings (leaf color, etc.) and draw a picture to represent their observations.

After the third observation in spring, students may be ready to make inferences about the measurement changes they recorded. By making observations throughout the year, students will observe that the shadow points away from the Sun and that its length varies during the different seasons. As students compare the three observations they will discover a pattern—fall: shorter shadow, winter: longer shadow, spring: shorter shadow. For some students, it may be developmentally appropriate that they simply understand that a change occurred.

Finally, students could draw a picture including their three observations and describe their pictures either orally or in writing to complete their journals.

For Grades 4–6: Arctic Lights, Arctic Nights

Before reading Arctic Lights, Arctic Nights, show the class where Alaska is located on a globe or map with respect to the North Pole and the Arctic Circle. Ask students to elaborate on their understandings of sunshine in Alaska. Typically, students comment, “It is either dark all day or light all night;” “The Sun never sets in Alaska;” and similar comments that may show misconceptions about their knowledge.

At certain locations in Alaska (within the Arctic circle), 24 hours of sunlight does occur for part of the year. However, this does not hold true for all of Alaska. Remind students that regardless of what happens with the seasons, the time it takes Earth to rotate on its axis is still 24 hours.

Next, provide students a blank data-collecting sheet (shown completed in Figure 1), and begin to read the book aloud—stopping at each page to have students record information such as sunrise and sunset times, temperature range, and amount of daylight. This is an opportunity to review abbreviations for hour and minute, correct recording of times, the symbol for degrees, and the meaning of F or C after a temperature.

As the story continues, have students record data month by month. Spending 45 minutes to an hour reading the story allows students to record data and enjoy the story. Although there can be many discussions about the pictures and storyline, the first significant conversation occurs when students notice that there is no significant temperature change between June and July even though the amount of sunshine decreases. With some guiding questions, students arrive at the conclusion that the atmosphere holds some of the Sun’s heat even with less daylight hours.

After discussing December, ask students to predict the length of daylight in January and to explain their reasons why they believe their prediction is correct. Most students predict a shorter time, as that is the pattern they have observed as the story moved from summer, which has the longest day of the year, to winter, which has the shortest day of the year. Once they have explained their reasoning, reread the sentence about the winter solstice that begins with “During this shortest day of the year, …” and ask students if anyone would like to change their prediction. Most revise to over five hours, which is confirmed as the January pages are read to a variety of cheers and comments.

After completing the book, students have collected a lot of data about this part of Alaska’s sunlight and temperatures. To better “picture” the data, students can create a line graph marking the monthly data and estimating the length of day to the nearest half-hour. This is a challenging activity for the younger students, but understanding comes quickly to those older students who have some background in coordinate grid activities.

Investigating actual data from Alaska allows students to see the connections between the seasons and day length. Next, they can create similar graphs of their own geographic location.

Meri-Lyn Stark (mstark@pcschools.us) is an elementary science specialist in the Park City School District in Park City, Utah.

Resources

National Research Council (NRC). 1996. National science education standards. Washington, DC: National Academy Press.

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