SEASONS

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SEASONS
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We know that the reason we have day and night is
because the Earth
rotates.
Rotate means
to turn.
The Earth rotating on its ______ gives
us day and night.
axis
Earths axis is
the imaginary line that goes through the center
of the Earth.
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But guess what! Rotating isnt the only way the
Earth moves in space!
The Earth also revolves.
Revolve When one object moves around another
object
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How long does one revolution take?
It takes the Earth one year, or 365 ¼ days to
orbit the sun.
Does anyone know what orbit means?
Orbit -
The path that an object follows as it revolves
around another object.
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But why do we have four seasons?
Its because the Earths axis is tilted.
Take a good look at our globe. Its not tilted
like that because it looks nice. No way. Thats
the way the Earth is tilted in space.
That tilt gives us seasons!
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Look at this diagram. Notice how the Earth is
always tilted in the same direction. As the
Earth __________ the part of Earth tilted toward
the sun changes.
revolves
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SUMMER SOLSTICE/June Solstice

• The longest day of the year
• Marks the beginning of summer
• June 20 or 21
• Northern Hemisphere is tilted closest to the Sun

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Summer SOLSTICE/JUNE SOLSTICE
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WINTER SOLSTICE/December Solstice

• The shortest day of the year
• Marks the beginning of winter
• December 21 or 22
• Northern Hemisphere is tilted farthest away from
  the sun

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wINTER SOLSTICE/DECEMBER SOLSTICE
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FALL EQUINOX/September equinox

• Northern and Southern Hemispheres are the same
  distance from the sun
• Marks the beginning of fall
• September 22 or 23

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Fall quinox/SEPTEMBER EQUINOX
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SPRING EQUINOX/March Equinox

• The day at which the Northern and Southern
  Hemispheres are the same distance from the sun.
• Marks the beginning of spring
• March 20 or 21

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SPRING EQUINOX/MARCH EQUINOX
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During part of the year the North Pole tilts
towards the sun. This season is ________.
summer
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During another part of the year, the North Pole
points away from the sun. This season is ______.
winter
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When the North Pole is tilted toward the Sun, the
Sun travels higher overhead in the sky. The
Suns rays shine straighter down on that part of
the Earth. It is summer in that part of the
Earth.
Its like pointing a flashlight at a piece of
paper. When you hold the flashlight straight
above the paper, the rays from the flashlight
shine down straighter.
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When the North Pole is tilted away from the Sun,
the Sun stays lower in the sky. It is then
winter in that part of the Earth.
If you point your flashlight at a piece of paper
at an angle, the rays from the flashlight spread
out.