This hands-on activity will help students understand why summer is hotter than winter.
Main Curriculum Tie:
Science - 6th Grade
Standard 2 Objective 1
Describe the relationship between the tilt of Earth's axis and its yearly orbit around the sun.
- Centimeter Grid
- Centimeter Grid paper (pdf)
- Darkened room (Taping
black paper over the
- Piece of cardboard or
- Clear tape
Background For Teachers:
There are two ways Earth’s tilt causes seasons. The first is that there
are more daylight hours when we are tilted toward the sun in summer,
and fewer in the winter when we are tilted away. The second reason is
that when the sun is high overhead, we receive more direct sunlight; in
the winter the opposite is true. Therefore, the reason that summer is
hotter than winter is two-fold. First, the days are longer, so the sun has
longer to heat Earth. Second, the sun’s rays are more directly overhead,
delivering more heat to Earth.
Intended Learning Outcomes:
1. Use Science Process and Thinking Skills
3. Understand Science Concepts and Principles
4. Communicate Effectively Using Science Language and Reasoning
Invitation to Learn
Ask students why they think we have seasons. Many will say because
we are closer to the sun in summer than in winter. To help overcome this
misconception, tell students that we are actually closest to the sun in
January. Then tell them that there is a space heater at the back of the
classroom. Imagine you are really cold and want to get warmer. Ask for
suggestions on how to get warmer. They will probably tell you that they
need to get closer to the heater. Take a baby step forward and ask if this
will help warm you up. They say no. Point out that the difference
between Earth’s farthest distance from the sun and its closest is
comparable to that baby step. Therefore, Earth’s distance from the sun
plays a very small role in its temperature variation.
- Cut the Centimeter Grid transparency so that it will
cover the flashlight with a little overlap. Tape the transparency
over the lens of the flashlight.
- Place the flashlight so that it is parallel to the floor and
perpendicular to the wall; turn it on.
- Ask students what the grid looks like. Are all the grids the same
size? If some are smaller, which ones?
- Tilt a poster board at a 45° angle to demonstrate the tilt of
- Ask students how the gridlines have changed. Are all the grids
the same size? Which ones are larger? Which ones are smaller?
Why do you think they changed? If each square has the same
amount of heat, which squares do you think will get the hottest?
Why? Which ones will not heat up as quickly? Why?
- Have the students try this on their own in groups of three to four.
Have them tape a piece of graph paper to a piece of cardboard or
on a clipboard.
- Give each group a flashlight. Have them place the flashlight on a
pile of books so that the flashlight is parallel to the floor.
- Place the graph paper so that it is perpendicular to the flashlight
about 1 1/2 to 2 feet away (if you have mirror stands, they help
keep the cardboard upright). Aim the flashlight at the graph paper
then turn it on.
- Have students trace the area illuminated by the flashlight.
- Have students change the angle of the cardboard so that it is
leaning back away from the flashlight at an angle of 23.5°. Have
students trace the new area illuminated by the flashlight in a
- Have students change the angle again to 45° or 60° and trace the
illuminated area in a different color.
- Make sure that students keep the flashlights at exactly the same
distance from the cardboard throughout the activity.
Students may answer the following questions individually, in groups,
or as a whole class:
- Does the quantity of heat in the flashlight change as you change
- Of the three angles you tried, which one will heat up the
cardboard the most?
- Why do you think that one angle will heat up the cardboard more
Note to teachers: No matter what the angle is, the amount of light
energy from the flashlight remains the same. Therefore, the
greater the angle, the less intense the light energy on each square
will be and it will not heat up as much, due to the angle
increasing the size of the square, while the amount of light
Created Date :
Nov 15 2004 15:26 PM