This page first made public: Sep 15, Summary One of the most common and persistent scientific misconceptions is that Earth's seasons are caused by Earth's distance from the sun. This activity has been extensively tested, revised and retested for more than 15 years in the Concepts in Earth and Space Sciences course for future teachers at California State University, Chico.
It should work well in Earth science and astronomy courses from middle school to college level. Because this activity is designed to guide students toward discovery of the concepts, it works best if complete it before reading any explanations of or receiving any direct instruction about the causes of the seasons or why it is warmer at the equator than it is at the poles. Other materials needed in chronological order : Per Table: Flashlight Collection of spherical objects to represent celestial bodies as follows:.
Notes on Lab Activity 1: Scale Model of the Solar System I recommend doing the outdoor activity as a whole class with student volunteers to represent each planet; choose the tallest person in the class to pace off the distances.
When you get to "Earth," have the students place the moon at the appropriate distance from Earth and point out that, coincidentally, the moon and sun look the same size as seen from Earth. In the table at the bottom of page 2, fill in appropriate landmarks in your local area that are located at the model distances. Questions 1 and 2 on page 3 typically generate a great deal of discussion. The students may need a fair amount of prodding and questioning to get to the correct answers.
Place the globe on a counter so that it is tilted to the right or left i. Spring or Fall position with the Pacific Ocean facing the overhead projector -- having a relatively featureless part of the globe face the projector helps students see the grid projected on it more clearly, without being distracted by the details of complex shorelines or borders.
Notes on Lab Activity on the Causes of the Seasons Before students begin this activity, explain to them that each group will be asked to formulate an initial hypothesis to explain the causes of the seasons. The students will then try to use this hypothesis to explain a series of facts.
If their hypothesis is not up to the task, they must discard and reformulate, modify, or add to their initial hypothesis until it can provide a satisfactory explanation of the facts. Here are some sample questions: Why is it hotter at the equator than it is at the poles? There are several factors that influence the amount of sunshine received at various places on the earth. The major factor is that while the sun is overhead at the equator, it is at a rather slant angle at the poles.
This effect can be demonstrated using a torch, which can be taken as the sun. See Figure 1. What really counts is the amount of sunshine that falls on a given area.
It is all a matter of the angle the sun makes with a pole struck in the ground at local time of noon, when the sun is highest in the sky. The latitude can be thought of as the distance from the equator. As you move away from the Equator and towards the North or South poles, the weather tends to be colder.
The sun rays, however, hit the tropics at an angle leading to little heat. So, if the same amount of light rays fall on two different surfaces. On one surface, the light rays are directly overhead and concentrated in a specific area while on the other surface the light rays reach the surface from a slightly slanted angle and spread over a larger area.
The amount of rays reflected depend on the nature of the surface. Regions around the equator absorb a lot of sun rays leading to warmer conditions, unlike the polar regions the Arctic and Antarctica which reflect a lot of sun rays due to the massive snow.
The amount of sunlight absorbed and scattered while passing through the atmosphere depend on the nature and concentration of air molecules in the atmosphere. The presence of more air molecules and particles result in greater absorption and scattering of sun rays.
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