This is a fairly packed lesson. Although the subject (Earth's Tilt and Seasons) is somewhat simple, to promote clarity and address learners on a variety of levels, I provide many ways to explain and illustrate it. Onward...
I rang my chime to get the class’s attention. I announce that we are about to begin the fifth Science lesson in our unit about weather. I ask them to return to the carpet squares and ‘Show Five’. “How many of you thought the Earth was straight up and down?” Since we had just done a lesson on the Earth’s rotation, I want to see if they could access this prior knowledge to connect their experiences with a different perspective of our planet. A few students raise their hands but no comments were shared. “Based on what we learned about the earth’s revolution, where is the Earth in relation to the sun?” “It moves around it in a circle.” “Right! So today, we’ll learn more about about the Earth’s position and how it affects us.”
I read them a book called The Shortest Day, by Wendy Pfiffer. She's a fantastic writer of kid-friendly Science-centered books. (As an aside, I always spring for the hardcover books when they are closely tied to my lessons. They just last longer.). While the book focuses on Winter, I chose it because it gives a look at other times of the year, even to the point where it shows how the position of the sun on the horizon relates to the season, a helpful visual for a teachable moment.
Once I finish reading, I continue, “In the last lesson, we saw how the Earth takes a year to revolve around the Sun. This is important because the location of the Earth in relation to the Sun determines the season- the time of the year. We're going to learn more about them now. The seasons are (I count them off on my fingers, I ask them to repeat after me) ‘Winter’, ”Winter”, ‘Summer’, “Summer”, ‘Spring’, “Spring”, and ‘Autumn’ “Autumn”. Autumn is another word for Fall. It's is the Science word for it.”. I work to translate commonly used words into Science terms, both to raise their vocabulary and give them a wider understanding. “Why do you think this position of the Sun could matter to the weather?” “What if it gets too cold or hot?” “Exactly right. There’s another part of this position that is important too. The Earth tilts a little bit, 23.5° to be exact”, as I demonstrate the angle with my hand. “Just like with the revolution, the tilt of the Earth makes places around the world warmer or colder based on how close it is to the Sun.”
I get a flashlight and our globe to do a very quick demonstration of ways the tilt of the Earth affects how the Sun reaches some areas more than others, an important concept to deepen the understanding of seasons. “Let’s get the Daily Helpers up here to demonstrate this idea.” For logistic and management reasons, I almost always choose Daily Helpers for jobs like this. It saves on the angst when students don’t get chosen if they know the expected routine. I ask one student to hold up the globe. I gave the other one the flashlight and helped them position it correctly. “Who notices where the light is shining? Can you share it with us?” When practical, I really like to begin instruction with a question for two reasons. First, it helps me gauge the pace and depth of my instruction because I better know what they know. Second, it is a great way to acknowledge the students’ ideas, showing them their ideas are just as important as mine. “Notice how the sun is shining on a certain place on Earth. Now keep your eye on that place as we walk around the sun. There are four equal parts- quarters (I may as well raise their vocabulary and introduce a future Math term!)- of our circle. Each one represents one season. One whole revolution around the Sun equals a year.
“Notice how the place where you look gets less light at certain times.” “I see it.” “That must make it...” “Cold….!” “Right! Where the Sun shines more, it is hotter." I want to use this opportunity to introduce some Math vocabulary like ‘more’ and less’ to support upcoming CCSS lessons. To extend this concept, I follow up with a cute TeacherTube clip that does a great job extending our demonstration and explaining this Earth tilt/season in an entertaining and kid-friendly way (the narration voice may make you giggle though. Fair warning!).
After the whole class instruction finishes, I tell them “It’s time for us to create a model that shows the way the Earth revolves around the Sun to create seasons. The first part, the big hot star that gives us heat.. “Sun!” “Right. And the planet where we live that rotates around the Sun is called..” “Earth” “Yep. When the Earth rotates around the Sun, it creates… “Seasons”.
• First, you’ll cut out the two parts shaped like circles- Sun and Season Cycle.
• Next, you’ll put the two circle together, picture facing up, with the Sun on top.
• Last, get a metal connector and poke it through the middle of each circle.
When you connect the two parts, you can turn the bottom part to demonstrate the seasonal rotation. I’ll be walking around to help you. I expect you to work carefully. If you finish, discuss the ideas we learned with a table partner while you accurately color the Sun.”. I always emphasize accurate coloring for two reasons. First, color helps the brain organize the information that was learned. Color will also help them retain accurate information. Additionally, when the product goes home, it lets the families know that we take the important work we do at school seriously. One fun extension you could do is have the students locate their current or native home on the globe. That gives them valuable perspective of the seasons as it effects somewhere that matters to them. As they work, I circulate among the students as they complete this assignment to spend adequate time listening to their comments (“The atmosphere is around the earth.” “A season is only in one place at a time.”, asking for clarification (“Tell me more about that.”) when necessary. This act both to access prior knowledge as well as a formative assessment.
After the season models are complete, I use a chime to single the end of this lesson piece. I ask the students to put away the projects in their bags before the return back to their carpet squares. I ask them a simple question, “Tomorrow, when we do our calendar routine, what's another thing we can consider?” “The season!” “What season is it now, anyway?” “Winter!” Looks as if they took the connection about how seasons affect us and took it one step farther. Sounds like my job is done.