Bell Work:

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Bell Work

• What causes the seasons?
• Why is it one season in one part of the world and
  another season in another part of the world at
  the same time?
• What causes a day on Earth? How long is a day on
  Earth?
• How can we tell when Earth has gone through a
  month?

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How Does the Earth Move?

• Hold on tight to your desk!! You cant feel it,
  but you are traveling at a speed of 30 km per
  minute. The earth is actually traveling at this
  speed in an elliptical path (like an oval) around
  the sun.
• This path is called an orbit.
• Each complete orbit, or revolution around the
  sun, takes 365¼ days, or one year.

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How Does the Earth Move?

• The earth has a second type of motion. It spins
  or rotates, like a top.
• Each complete rotation of the earth takes 24
  hours. This motion gives us night and day.

In the picture, City C is experiencing sunrise.
Which city has had sunlight for about one
hour? Which cities are still dark? Which city
will be the next to experience sunrise?
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Seasons

• The Earth is tilted on its axis at a 23.5 angle.
  This tilt affects how much solar energy an area
  receives as the Earth moves around the sun.
• The seasons are caused by the tilt of Earths
  axis as Earth travels around the sun.

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The Tilt of the Earth and its rotation around
the sun are what causes the different seasons.
Check this out!
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Summer June

• During our summer months the Northern Hemisphere
  has warmer temperatures and longer days because
  it tilts toward the sun and receives more direct
  solar energy for a longer amount of time.
• However, the Southern Hemisphere has cooler
  temperatures and shorter days because it is
  tilted away from the sun.

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Winter December

• During our winter months the Southern Hemisphere
  has higher temperatures and longer days because
  of it tilts toward the sun and receives more
  direct solar energy.
• The Northern Hemisphere has lower temperatures
  and shorter days because it tilts away from the
  sun.

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Spring and Fall March September

• Neither end of Earths axis is tilted toward the
  sun. Both hemispheres receive the same amounts
  of energy.

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• Seasons

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Bellwork

• How is the Northern Hemisphere facing when we are
  having winter?
• During what season do we have the longest amount
  of daylight?

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Months Lunar Calendar

• We can keep track of months in the year by the
  phases of the moon (lunar calendar).
• The phases begin with the new moon.
• As the Moon moves around the Earth, we get to see
  more and more of the illuminated surface. We see
  the following phases
• Day 4- waxing crescent
• Day 7- first quarter or half moon
• Day 10- waxing gibbous.

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Months Lunar Calendar

• Two weeks after the new moon (third week), the
  moon is now halfway through its revolution, and
  now the illuminated half coincides with the one
  facing the Earth, so that we can see a full disk
  we have a full moon on day 14.
• From now on, until it becomes new again, the
  illuminated part of the Moon that we can see
  decreases, and we can see the following
• Day 18- waning gibbous
• Day 22- Third Quarter or half moon
• Day 26- waning crescent

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Months Lunar Calendar

• A while after four weeks (29.5 days, more
  precisely) the illuminated half of the Moon again
  faces away from us, and we come back to the
  beginning of the cycle a new moon.

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1. New Moon
The side that Earth sees is completely
dark. Draw a circle and shade the entire circle.
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2. Waxing Crescent

• Right side isilluminated.
• Left side is shaded.

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3. 1st Quarter Moon

• Right side is illuminated.
• Left side is shaded.

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4. Waxing Gibbous Moon

• Right side is illuminated.
• Left side is shaded.

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5. Full Moon

• The whole moon is illuminated.

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6. Waning Gibbous

• Left side is illuminated.
• Right side is shaded.

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7. Third Quarter Moon

• Left side is illuminated.
• Right side is shaded.

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8. Waning Crescent Moon

• Left side is illuminated.
• Right side is shaded.

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Review

• 1. How long does it take for the earth to go
  around the sun? What are the two names for that
  path?
• 2. How long does it take for the earth to
  experience one day and one night? What are the
  two names for that time?
• 3. Define and draw the four types of tides.
• 4. Our calendar is based on what?
• 5. Tidal range is greatest during
• 6. What is a tidal bore?
• 7. In the summer we have longer days and ____
  temperature.
• 8. What are seasons caused by?
• 9. What do you call the difference between the
  levels of water at high tide and low tide?
• 10. The gravitational pull of the moon on earth
  is greatest on_____.

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Discussion Questions

• Which movement of the earth gives us our 24-hour
  day?
• Which movement of the earth gives us our 365¼ day
  year?
• How many complete rotations has the earth made
  this month?
• How many complete revolutions has the earth made
  since you were born?