Why Do We Have Seasons?
Name___________________________
Educational Standard/s Addressed
Standard 8-1: The student will demonstrate an understanding of technological
design and scientific inquiry, including process skills, mathematical thinking,
controlled investigative design and analysis, and problem solving.
Standard 8-4: The student will demonstrate an understanding of the
characteristics, structure, and predictable motions of celestial bodies
Primary Performance Objectives: The following South Carolina Scientific inquiry
Indicators are the primary focus of the lesson.
Indicator 8-4.5: Explain how the tilt of the Earth’s axis affects the length of the
day and the amount of heating on Earth’s surface, thus causing the seasons of the
year.
Introduction:
Have you ever wondered what caused the seasons? Is it the Earth’s orbit or the Sun?
Perhaps it is both working together. In this lesson we will learn about what is actually
causing Earth to have seasons.
Materials (per group):
1. 1 small Styrofoam ball
2. 1 stick
3. 1 flash light
4. 1 piece of cardboard with a hole cut in it
5. 1 Styrofoam base
6. 1 ruler
Model Set-up:
1. Starting at the top of the Styrofoam ball, drive the stick all the way through the
globe attempting to make it come out at the bottom (Note: It does not have to be
perfect, but the closer the better). The Styrofoam ball should rest in the middle
of the stick.
2. Divide the ball in half to simulate the equator and label where the United States
would be.
3. Insert the end of the stick into the Styrofoam base at a slight angle (see diagram).
Cardboard
with hole
40 cm
4. Turn on your flash light and place it 40 cm from the leading edge of the
Styrofoam base.
5. Continue to lab procedures.
Procedures:
1. Put your hand against the flashlight. How does it feel warm or cold? (Discuss
with your group)
2. Move your hand away from the light source. Do you notice any changes in
temperature? Is it still warm? More or less then before? (Discuss with your group)
3. Move your hand further and nearer the light, tip it so it is at an angle. Describe the
differences you feel with your group
4. Now you can show the way light produces heat using your paper. Prop a book up
at an angle and lay the piece of paper on it. Lay the flashlight on another book so
that it shines onto the paper. Feel the paper and notice when it starts to get warm.
Measure 10 cm from the light source and mark the spot on the paper. Keep feeling
that bit. How long does it take to get warm? (Discuss with your group)
5. Let your paper cool off. This time prop your book upright. 10 cm away from the
light. Fix your paper to it with a piece of tape. Check the area of the paper
opposite the center of the flashlight. How long does it take the paper to get warm
this time? Feel the area to the top of the paper. Which is warmer, the top or the
center? (Discuss with your group)
Model Procedures
1. Begin with the stick pointing toward the light source.
2. Rotate the globe so that the United States is on the same side as the light.
3. Hold the cardboard so it is at the edge of the Styrofoam base (see diagram
above) so that there is a circle of light on the United States.
4. Trace the outline of the circle of light on the globe.
5. Rotate the Styrofoam base so that the sharpened stick is pointing away from
the light source.
6. Repeat steps 2, 4 and 5.
Questions:
1. What does the stick represent?
2. Were the circles you traced the same size? What do you think is the reason?
3. Which setup represents summer (stick pointed toward the light or stick pointed
away from the light)? Explain your answer.
4. Draw a picture of how the setup would look during the spring or fall.
5. Given that the term solstice refers to the days of the year when the sun is at its
highest or lowest points in the sky (and can also pertain to the longest/shortest
days of the year), label the locations on the diagram below that correspond with
this term.
6. Given that the term equinox refers to the days of the year when the sun is at the
middle point in the sky (and can also pertain to the two days when the amount of
daytime = the amount of nighttime), label the locations on the diagram below that
correspond with this term
E
E
S
E
E
Pre-MacModS
NAME_________________________
Axis
Earth
Sun
The diagram above represents which season for the United States?
a. Winter
b. Spring
c. Summer
d. Fall
Explain your choice below.
Post MacModS
Name_______________________
Axis
Earth
Sun
The diagram above represents which season for the United States?
e. Winter
f. Spring
g. Summer
h. Fall
Explain your choice below.