The Earth's Seasonal Patterns
Lesson 6 of 10
Objective: SWBAT explain why the Earth has seasons.
Inquiry Based Instructional Model
To intertwine scientific knowledge and practices and to empower students to learn through exploration, it is essential for scientific inquiry to be embedded in science education. While there are many types of inquiry-based models, one model that I've grown to appreciate and use is called the FERA Learning Cycle, developed by the National Science Resources Center (NSRC):
A framework for implementation can be found here.
I absolutely love how the Center for Inquiry Science at the Institute for Systems Biology explains that this is "not a locked-step method" but "rather a cyclical process," meaning that some lessons may start off at the focus phase while others may begin at the explore phase.
Finally, an amazing article found at Edudemic.com, How Inquiry-Based Learning Works with STEM, very clearly outlines how inquiry based learning "paves the way for effective learning in science" and supports College and Career Readiness, particularly in the area of STEM career choices.
In this unit, students begin by studying the location of the Earth in the Universe. Then, students learn about the brightness of stars through investigations and research. At the end of this unit, students explore the patterns on Earth, such as day/night and the length of shadows.
Summary of Lesson
Today, I open the lesson by asking students to graph the average monthly temperatures in Bozeman, Montana. Students then explore why the Earth has seasons through videos, online research, and demonstrations. At the end of the lesson, students reflect and apply their new understanding of Earth's by writing evidence-based explanations.
Next Generation Science Standards
This lesson will support the following NGSS Standard(s):
5-ESS1-2. Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night, and the seasonal appearance of some stars in the night sky.
Scientific & Engineering Practices
For this lesson, students are engaged in Science & Engineering Practice:
Science & Engineering Practice 4: Analyzing and Interpreting Data
At the beginning of this lesson, students represent data in a bar graph. Then, they analyze how the average monthly temperatures change over the period of a year.
To relate ideas across disciplinary content, during this lesson I focus on the following Crosscutting Concept:
Crosscutting Concept 1: Patterns
Students study how seasonal patterns and temperatures on Earth are caused by the revolution and tilt of the Earth.
Disciplinary Core Ideas
In addition, this lesson also aligns with the following Disciplinary Core Ideas:
ESS1.B: Earth and the Solar System
The orbits of Earth around the sun and of the moon around Earth, together with the rotation of Earth about an axis between its North and South poles, cause observable patterns. These include day and night; daily changes in the length and direction of shadows; and different positions of the sun, moon, and stars at different times of the day, month, and year. (5-ESS1-2)
To add depth to student understanding, when I can, I'll often integrate ELA standards with science lessons. Today, students will work on meeting CCSS.ELA-LITERACY.RI.5.7: Draw on information from multiple print or digital sources, demonstrating the ability to locate an answer to a question quickly or to solve a problem efficiently. In this lesson, students will be use multiple resources to collect key information involving the seasons on Earth. In addition, this lesson supports CCSS.ELA-LITERACY.W.5.2: Write informative/explanatory texts to examine a topic and convey ideas and information clearly. After researching the revolution and tilt of the Earth, students write an informative paragraph to convey their ideas about the four seasons.
Choosing Science Teams
With science, it is often difficult to find a balance between providing students with as many hands-on experiences as possible, having plenty of science materials, and offering students a collaborative setting to solve problems. Any time groups have four or more students, the opportunities for individual students to speak and take part in the exploration process decreases. With groups of two, I often struggle to find enough science materials to go around. So this year, I chose to place students in teams of two or three! Picking science teams is always easy as I already have students placed in desk groups based upon behavior, abilities, and communication skills. Each desk group has about six kids, so I simply divide this larger group in half or thirds.
Gathering Supplies & Assigning Roles
To encourage a smooth running classroom, I ask students to decide who is a 1, 2, or 3 in their groups of three students (without talking). In no time, each student has a number in the air. I'll then ask the "threes" to get certain supplies, "ones" to grab their computers, and "twos" to hand out papers (or whatever is needed for the lesson). This management strategy has proven to be effective when cleaning up and returning supplies as well!
Teacher Note: This is a lengthy lesson that could easily be divided into two days of instruction!
Partners & Computers
During today's lesson, students will be working in teams of two students (elbow partners). Each team of students will have one laptop computer to share. While we have enough computers for all students, I have found that partners are more successful collaborators when they are sharing one device.
For the Sun and Earth's Patterns Unit, students are creating an envelope book to help organize new information and to support an inquiry approach during the learning process. Prior to the unit, I used a plastic comb binding machine (pictured below) to create envelope books using 10 envelopes for each student's book: Envelope Books. During today's lesson, students will be working with the sixth envelope in their books.
For each envelope, students are provided with up to 3 vocabulary cards: Vocabulary Cards (I copied these onto green card stock paper & cut each page into 10 cards): Vocabulary Cards. For easy distribution, I placed these cards into ziplock baggies so that each group of students could easily take cards out as needed: Vocabulary Cards in Bags. As an opening to the lesson, I write the following vocabulary words on the board: Northern Hemisphere, Southern Hemisphere, and season.
Students work together with their partners to discover the meaning of each word, using their computers and/or dictionaries as resources. As students are ready, they share definitions out loud with the rest of the class. We discuss student findings and then I construct a student-friendly definition (using student input) for all students to record on their cards. This process is important for two reasons: (1) sometimes students record definitions that are difficult to understand due to complex language and (2) this also allows students to see how important it is to use multiple sources when conducting research.
Here's an example of student vocabulary cards: Student Vocabulary Cards.
Before students develop a guiding question for the day, I want students to represent data in graphical displays to reveal patterns of monthly changes in temperature in Bozeman, Montana (the city we live in). By noticing patterns in temperatures, students will begin to see the relationship between temperatures, seasons, and the positions of the Sun and Earth at different times of the year.
Teacher Note: This task supports NGSS standard 5-ESS1-2 (Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night, and the seasonal appearance of some stars in the night sky) and Disciplinary Core Idea 5-ESS1-2: Earth and the Solar System (The orbits of Earth around the sun and of the moon around Earth, together with the rotation of Earth about an axis between its North and South poles, cause observable patterns. These include day and night; daily changes in the length and direction of shadows; and different positions of the sun, moon, and stars at different times of the day, month, and year).
Graphing Average Monthly High Temperatures
I pass out a copy of this Average Temperatures Graph (one half sheet per student) and ask each pair of students to visit the following link: US Climate Data on Bozeman, Montana. To get students acquainted with this site, I ask students a variety of questions:
- Turn & Talk: During which month or months does Bozeman receive the highest amount of precipitation? (May & June)
- Turn & Talk: During which month does Bozeman receive the highest amount of snowfall? (December)
- Turn & Talk: Which month is the warmest? (July)
I explain: Today, you are going to be identifying the average high temperature in Bozeman, Montana during each month throughout the year. As you gather this information, you will be graphing the temperature data on the provided graph.
I remind students of the importance of choosing an appropriate scale interval on the y-axis in order to ensure that the highest data point can be graphed. Students agree that 83 degrees Fahrenheit its the "highest" average high throughout the months in Bozeman, Montana. Then, they agree: if the scale interval is 10 degrees, the last tick on the y-axis would be equal to 100 degrees, allowing for the highest data point to be graphed.
I model how to graph the first data point, January's average high is 35 degrees Fahrenheit. I also ask students to write 35 degrees at the top of the bar so that they have exact evidence to refer to when developing explanations later on.
Students Graphing and Making Observations
After modeling how to create a scale and graph the average high temperature in January, students continue on their own: Students Graphing Data. Once students are finished, I ask them to begin making observations of their graphs. We then discuss their observations as a class (Making Observations). Some students comment:
- The graph looks like a big hill.
- I was surprised to see that July was warmer than June.
- In January it’s cold and in December it’s warm. In the middle it gets warm.
Coloring the Seasons
This leads us into a wonderful discussion about the seasons. I continue: What are seasons again? (a period of the year characterized by weather conditions) Do you remember one student pointing out that seasons are "quarters of a year?" If we have twelve months, what is one fourth of 12 months? (3 months.... because 3 months x 4 = 12 months).
I ask students to get out a blue, pink, orange, and blue marker. While projecting my Teacher Graph Model (which was not colored to begin with), we color the bar graphs one-by-one accordingly: Which three months are the coldest in Bozeman, Montana? (December, January, February) Let's color these months blue. What season do you think these three months represent? (Winter)
Which three months are the warmest? (June, July, August) Let's color these months yellow. What season do you think these months represent? (Summer)
We continue on by coloring and labeling the spring months (March, April, May) pink and the Fall months (September, October, November) orange.
Here's an example of a student graph during this time: Student Graph Example. I could see the students beginning to view seasons and temperatures differently! All of a sudden, everything began to make sense! It's amazing how adding a little color helps with sense-making.
Developing a Guiding Question
To support an inquiry-based learning model and Science & Engineering Practice 1 (Asking Questions and Defining Problems), I explain: Today, you will be learning about the seasons. First, let's talk about the questions you have about seasons. What guiding question do you think we should research today? Student questions include:
- How does the rotation of the Earth change the seasons?
- How come the summer is warmer than winter?
- How does the Northern Hemisphere and the Southern Hemisphere affect the seasons?
- Why does the Earth have seasons?
- Why are there only four different seasons?
As students share their thinking, I'm hoping that with some teacher guidance, students will reflect upon the vocabulary words and ask, "Why does the Earth have seasons?" Sure enough, many students mentioned this question during our conversation.
Here's a video of this question-development process in action: Developing a Guiding Question.
Lesson Introduction & Goal
Now that students have helped develop a guiding question, I introduce today's learning goal: I can explain why the Earth has seasons.
I continue on by passing out an envelope picture to each student: Envelope 6 Pictures. Pictures add an element of excitement to learning and they provide support for students who learn best using visual aids.
On the front cover of the sixth envelope in student envelope books, I model how to paste the picture and write the investigative question for today's lesson: Why does the Earth have seasons? (Student Envelope Example).
At this point, students are ready to begin exploring, researching, and collecting evidence!
I pass out a copy of the Main Idea Wheel Graphic Organizer to each student. I'm happy to hear one student immediately suggest, "We should write 'Why does the Earth have seasons?' in the middle!" I project and model how to do this using my teacher copy (Modeling the Main Idea).
To get students started on their research, I show two video clips. During this time, the students discuss and agree to record the supporting details. Per student suggestion, I project and record the following notes: Teacher Modeled Notes.
Video Clip 1
During this video clip, the narrator explains how the Earth is tilted on it's axis and how this tilt impacts the angles in which the sun's rays reach Earth. The class agrees to record, "The Earth is tilted on its orbit around the sun. The axis is tilted by 23 degrees." Later, students agree, "The sun's rays reach us at different angles because of the Earth's tilt. The sun's energy is spread out more in the Northern Hemisphere." I stop this video at 1:52 as only the first half the of the video supports today's guiding question.
Video Clip 2
During this video, students learn the same concepts in a different way. Students agree to take the following notes, "The Earth's tilt causes the sun's energy to be spread out over a greater area. When parts of the Earth receive less energy, it is wintertime. When parts of the Earth receive more energy, it's summertime." Following this video, I hear several students say, "Oh, now I get it." This is a great reminder of the importance of layered instruction. Many students need multiple explanations in multiple formats in order to develop an understanding of a new scientific concept.
At this point students continue researching the guiding question (Why doe the Earth have seasons?) with their partners. I share the following link, The Earth-Moon-Sun System, and ask students to study page 193.
Monitoring Student Understanding
Once students begin working, I conference with every group. My goal is to support students by asking guiding questions (listed below). I also want to encourage students to engage in Science & Engineering Practice 7: Engaging in Argument from Evidence.
- What question are you researching?
- What patterns have you noticed?
- Why do you suppose ____?
- What have you found so far?
- Has your thinking changed?
- What evidence do you have?
- How did you decide _____?
- What conclusion can you draw about ____?
Here, Conferencing with Students, students are beginning to develop an explanation of why the Northern Hemisphere is warmer in the summer and colder in the winter. I'm hoping that by questioning them, it encourages them to think deeply about their collected facts and to begin developing explanations.
Here's an example of student notes during this time. Most students were able to complete the graphic organizer.
Reflect & Apply
Before students reflect and apply on today's findings in writing, I want students to apply their understanding of the Earth's tilt and the seasons by 1) participating in a class demonstration (four globes positioned around a lamp) and by 2) investigating the Earth's tilt by creating their own models (using a tennis ball as the sun and a styrofoam ball as the Earth).
Prior to this class demonstration, I created Season Cards and Energy Cards. I also placed four globes around a light at the back table, making sure the axis of each Earth pointed in the same direction. Using masking tape, I divide the table into four sections for each of the four seasons: Four Globes Around a Light. (At the end of this demonstration, the table will look like this: Four Globes After the Demonstration.)
I invite students to join me at the back table. Here's a video clip that captures our discussion: Modeling the Revolution of Earth.
I begin by asking students to observe the position of the Earth's axis at each point in its revolution around the sun. Where do you think the North Pole is always pointed? (the North Star) I then direct students' attention to the Summer and Winter positions and ask: Who can tell me the difference between these? A student refers to the Earth in the summer position and comments, "The Northern Hemisphere is closer to the Earth so that must be summer." I then place the "Summer" card next to this Earth.
We then discuss the fact that the Northern Hemisphere is tilted away from the Earth in the Winter position.
Once all of the globes are labeled, we then discuss the amount of sunlight the Northern Hemisphere receives during each of the seasons using the Energy Cards.
I want to provide students with the opportunity to recreate the demonstration using their own tools. At this time, I ask students to work in groups of three. I invite one student to grab a Bag of Supplies, which includes a tennis ball (sun), styrofoam ball (Earth), toothpick, and a black sharpie. Once students are ready, I model how to stick the toothpick through Earth and how to draw a line representing the equator: Drawing the Equator. We also place a dot in the Northern Hemisphere of the Earth to represent the position of North America.
I then show the following video clip to students several times as they work together as a group to recreate and explain the tilt and revolution of the Earth: Earth Orbitting the Sun.
Now that students have built meaning and understanding by observing, questioning, and exploring, it is important to provide students with the opportunity to apply their findings. For this reason, I invite students to use their research and investigations to answer the guiding question, "Why does the Earth have seasons?" by writing fact-based explanations on the following handout: Explanations of the Seasons.
To make sure students are successful, we discuss which seasons are represented in each picture. Then, students continue explaining which season is occurring in each picture and why.
Here are a couple examples of student work during this time:
At the end of this lesson, students place the following items in today's envelope: