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 PUPILS
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Learning Objectives: By the end of
this lesson you should understand all about the way the earth
moves, and how this movement creates seasonal weather. |
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The earth is in constant motion. It has
two key movements: ORBIT and ROTATION. Another important factor is the
fact that the earth leans a little to the side, on its AXIS.
Key Definitions:
- Orbit: the path the
earth takes as it moves around the sun.
- Axis: the tilt of
the earth as it orbits the sun and rotates.
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If we can understand these two key definitions,
we can understand why we have climate changes on the earth.
Here we go!
Read for Understanding
1. The
earth's ORBIT around the sun (the easy part)
The first movement we will learn about is called the earth's
ORBIT.
The earth's ORBIT is the path it takes around the sun.
This journey takes exactly one year, which is why we have birthdays every year!
Thank the earth's ORBIT for all of those presents you get!
2. The earth's AXIS (the hard part)
So, now we know why we break our lives up into years, but
how do the seasons fit in?
The reason why we get four different seasons is because
the earth is tilted slightly on its side when it orbits. This tilt, called
the earth's AXIS, gives us our seasons. Sometimes we are tilted
close to the sun, and sometimes we are tilted away from the sun.
This might be very confusing for you right now, but your
teacher will show you a model of the earth's orbit, and demonstrate how being
tilted toward the sun will make the climate warmer.
Activities
Go to the website below and look at the very first graphic
on the page. It shows the earth moving around the sun. Around and
around it goes. Notice where it stops and make a note of the tilt of the
earth.
http://explorezone.com/earth/seasons.htm
Do you see how the tilt is different at the four points
where the graphic stops moving. These four points mark our four seasons.
Think about the answer to these questions:
- If we get all of our heat from the sun, at which time
of year are we tilted toward the sun?
- When are we tilted away from the sun?
- If we lived at the equator, what would our seasons be
like?
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