Download Reasons for the Seasons Webquest

REASONS FOR THE SEASONS WEBQUEST
Name: __________________________________
Section: _______________________
Objective: Model and illustrate how the tilted Earth rotates on its axis, causing day and night, and
revolves around the Sun causing changes in seasons.
An educational publishing company has hired YOU to produce posters for middle school science
classrooms. Your first poster is to be one that shows the causes of seasons on Earth. Since many
students have wrong ideas (misconceptions) about what causes seasons it is very important that your
poster be very accurate. Your poster will answer the question "What causes the seasons?" Before you
can start your poster, you must do some research on student ideas as well as the science behind the
seasons.
******Start by checking out the following interactive program on Why We Have Seasons
Part 1: Misconceptions about the Seasons
What are misconceptions? A misconception is an incorrect idea about something. Your task is to find
some common misconceptions about the reasons for the seasons.
A. Read the “Common Misconceptions about Day and Night, Seasons” paragraph below
B. Read “What Causes the Seasons? Common Misconceptions”
C. Read “Some Background Facts”
D. Read Misconceptions about Seasons (below)
MISCONCEPTION ABOUT SEASONS
1)
THE SEASONAL EFFECTS ARE THE RESULT OF THE EARTH’S AXIS FLIPPING BACK AND FORTH:
TRUTH: The Earth’s axis does slowly wobble like a top, completing one cycle in approximately 26,000 years. This motion is called precession,
and it is responsible for a gradual change in the location of the position in the sky where the Earth’s axis points. During the present epoch the
Earth’s axis is aimed toward Polaris, the North Star, in the constellation of Ursa Minor. It is around this star that the sky appears to pivot once
each day as the Earth rotates on its axis. Nearly five thousand years ago, when the Great Pyramid at Giza was constructed, the Earth’s axis
pointed towards Thuban in the constellation of Draco the Dragon. Ironically, if the Earth’s axis did flip back and forth during the interval of
six months, it could be demonstrated that every position on Earth would experience the same seasonal effects throughout the year.
2) MISCONCEPTION—THE FOUR SEASONS ARE THE RESULT OF THE CHANGING DISTANCE OF THE EARTH FROM THE SUN:
TRUTH: Most people believe this statement to be true. The seasons are caused in reality by the 23.5o tilt of the Earth’s axis and the axis always
pointing in the same direction. During the course of a year, this one phenomenon changes the duration of time in which the sun is visible in the
sky, the rising and setting positions of the sun along the horizon, and the noontime altitude of the sun. The Earth’s orbit is slightly elliptical
(oval) in shape. During a year’s time the Earth’s distance from the sun varies from approximately 91.5 to 94.5 million miles. We are actually
closest to the sun around January 2nd of each year and farthest from the sun around Independence Day, exactly the opposite of what one might
expect. CONSIDER THE FACT that the Southern Hemisphere experiences summer when the Earth is closer to the sun. Are the summers in
the Southern Hemisphere warmer? The answer is no. The Southern Hemisphere has less land. The excess heat is absorbed by the water which
has an extremely high heat capacity. This moderates the summertime temperatures in the Southern Hemisphere.
Common Misconceptions about Day and Night, Seasons
The polar regions’ extremes in lengths of the seasons and day and night are an intriguing introduction to misunderstood scientific
concepts. Research has long documented that people of all ages – elementary school children, college students, and adults – cannot
explain the cause of day and night or seasons. While the prevalence of these misconceptions, as well as the complexity of the
subject, makes it unlikely that students will leave elementary school with a complete and correct understanding, it is important to
assess, target, and challenge these misconceptions even in the early years.
We’ve listed some common misconceptions about the seasons and day and night as cited by educational research.
Day and Night Misconceptions
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The Sun goes behind hills.
Clouds cover the Sun.
The Moon covers the Sun.
The Sun goes behind the Earth once a day.
The Earth goes around the Sun once a day.
The Earth spins on its axis once a day.
The Sun moves across the sky.
The Earth rotates in a clockwise manner.
Seasons Misconceptions
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Earth is closer to the Sun during summer and farther away during winter.
Seasons happen at the same time everywhere on Earth.
Seasonal characteristics and change are the same everywhere on Earth.
The Earth’s orbit is an elongated (skinny) ellipse, making the distance between earth and sun vary dramatically over the
course of a year.
The tilt of the earth's axis of rotation puts the Northern Hemisphere significantly closer to the sun in June than the
Southern Hemisphere (producing summer in the Northern Hemisphere and winter in the Southern Hemisphere).
A common student answer for the cause of the seasons is that "the Earth tips toward the Sun in the Summer, . . .". This
conveys the impression that the Earth moves around its orbit and at certain times of the year the rotation axis suddenly
tips one way or another and thus we have seasons.
Record four misconceptions in the table below. You will be using this information to make part of your
poster.
1. _________________________________________________________________________
_________________________________________________________________________
2. _________________________________________________________________________
_________________________________________________________________________
3. _________________________________________________________________________
_________________________________________________________________________
4. _________________________________________________________________________
_________________________________________________________________________
Using these misconceptions, make part of your poster identifying common misconceptions and then
turn them into truths.
PART 2: TILT OF THE EARTH
How does the Earth's tilt affect the seasons? Research the websites below.
Include the following on all 4 drawings: Earth, its tilt, the sun, name of the season.
Earth’s Tilt Is the Reason for the Seasons!
Why Do We Have the Seasons?
Seasons and the Tilt
Seasons and the Tilt Interactive
Tilted Earth (podcast)
Using your research draw a picture of the Earth, showing its tilt, at each season,
Winter, Spring, Summer, Fall/Autumn
Use this information to make the second part of your poster about the tilt of the Earth.
Part 3: Earth Location and Seasons
The Earth is at four different points in its orbit around the Sun when we have each season.
Where is the Earth when it is summer (or winter, fall, and spring)?
Why is the hemisphere tilted towards the Sun warmer?
How are things different at the equator than at the poles?
For the Northern Hemisphere, when does the axis point most towards the Sun? When does the
axis point away from the Sun? At what point does the axis point neither towards nor away?
What is the special name for these two dates?
For this section draw a picture of the Earth revolving around the Sun through the year.
Show the Earth at its location during Winter, Spring, Summer, and Fall/Autumn.
Be sure to answer all of the questions listed above in this section of your poster.
Part 4: Day & Night
How does the angle of the sunlight that hits the Earth affect day and night?
Include a diagram with labels. Use the information to make the fourth section of your poster about
the angle of sunlight that hits the Earth causing day and night.
Part 5: Written Response
Write a paragraph explaining the reasons for the seasons, making sure to incorporate each part
of your poster into your paragraph.
Poster requirements:
Diagrams and drawings including labels will be used on every poster section to help illustrate
the concepts. The poster will be neat and all information will be easily found.
Take your time, and produce a neat and accurate poster explaining the reasons for the seasons.
Other Useful resources…
Earth’s Appearance at different times during the year
Seasons Interactive
Seasons Interactive 2
Observe Seasonal Changes
Poster Rubric
Students will:
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Describe the relationship between the tilt of Earth's axis and its yearly orbit around the
sun.
Describe the yearly revolution (orbit) of Earth around the sun.
Explain that Earth's axis is tilted relative to its yearly orbit around the sun.
Explain how the relationship between the tilt of Earth's axis and its yearly orbit around
the sun produces the seasons.
Compare Earth’s position in relationship to the sun during each season.
Use a drawing and/or model to explain that changes in the angle at which light from the
sun strikes Earth, and the length of daylight, determine seasonal differences in the
amount of energy received.
SUMMARY OF WHAT WE HAVE LEARNED
1. While the total number of hours in the days does not change from season to season, the
number of daylight hours does.
2. Our planet is not oriented straight up and down with regard to its motion around the sun.
It is actually tilted at an angle of 23.5 degrees off the perpendicular of its solar orbit (the
same angle at which most model globes are tilted.)
3. As Earth travels around the sun, the axis changes the orientation of the planet with
regard to the incoming solar radiation. This causes a change in the amount of light hitting the
planet’s surface at any position above or below the equator.
4. As the seasons change from spring to autumn, the axis is oriented toward the sun. From
autumn to spring, the axis is turned away from the sun. When the axis is pointed toward the
sun, more light falls on that hemisphere.
5. During the months of April through September, there is more light on the Northern
Hemisphere than on the Southern Hemisphere. The farther north one gets, the greater
number of daylight hours.