Chapter 2 Solar Energy and Seasons

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Chapter 2Solar Energy and Seasons
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Chapter 2Earth and the Suns Energy

• The Big Idea
• Earths movement and the suns energy interact to
  create day and night, temperature changes, and
  the seasons.
• Main Ideas
• Earths movement affects the amount of energy we
  receive from the sun.
• Earths seasons are caused by the planets tilt.

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Earths movement affects the amount of energy we
receive from the sun.

• All life on Earth requires solar energy, or
  energy from the sun, to survive.
• Amount of solar energy received changes
  constantly
• Earths rotation, revolution, tilt, and latitude
  all affect the amount of solar energy Earth
  receives.

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Rotation and Revolution

• Rotation
• Earth spins on its axis an imaginary line that
  runs through the center of the planet around
  which it turns.
• It takes Earth 24 hours to make one rotation, or
  complete spin on its axis.
• As Earth spins, different parts of the planet
  face the sun, thus causing the changes from day
  to night.

• Revolution
• Earth follows an orbit, or path, around the sun.
• Orbit is not a perfect circle.
• It takes Earth 365¼ days to complete one
  revolution, or trip around the sun.
• Our calendar year is based on the time it takes
  Earth to complete its orbit.

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Tilt and Latitude

• Tilt
• Earths axis is tilted at an angle of 23½ degrees
  from vertical.
• At any give time of year, some places on Earth
  tilt toward the sun, and others tilt away.
• Places tilting toward the sun receive more solar
  energy and have warmer temperatures than those
  that tilt away.

• Latitude
• Latitude is the distance north or south of
  Earths equator.
• Low-latitude areas, those nearest the equator,
  receive direct rays from the sun all year.
• High-latitude areas, those farther from the
  equator, receive indirect rays from the sun and
  have colder temperatures.

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Earths seasons are caused by the planets tilt.

• Seasons are periods during the year that are
  known for a particular type of weather.
• Many places experience four seasonswinter,
  spring, summer, and fall.
• In some parts of the world, seasons are based on
  the amount of rainfall

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The Seasons

• Winter and Summer
• Earth tilts away from sun in winter and towards
  the sun in summer.
• Because of the Earths tilt, the Northern and
  Southern hemispheres experience opposite seasons.

• Spring and Fall
• In spring, Earth begins to tilt toward sun, solar
  energy increases, temperatures rise, and days
  grow longer.
• In fall, the opposite occurs.

• Rainfall and Seasons
• In the tropics, regions close to the equator,
  seasons are marked by rainfall rather than
  temperature.
• At certain times of year, winds bring either dry
  or moist air to the tropics, creating wet and dry
  seasons.

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