Chapter 1 Section 2 Phases, Eclipses, and Tides

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Chapter 1 Section 2Phases, Eclipses, and Tides

• Objective Students will define phase, eclipse,
  and tide.

Star Log 2 What does phases of the moon mean?
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Phases of the Moon

• The positions of the moon, Earth, and the sun
  cause the phases of the moon, eclipses, and
  tides.
• The phase of the moon you see depends on how much
  of the sunlit side of the moon faces Earth.

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Moon Phases
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Moon Facts

• The moon does not have its own light, it
  reflects light from the sun.
• The amount of the sunlit side of the moon that
  you can see determines its phase.
• The moon goes through a whole set of phases about
  once a month.

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Solar and Lunar Eclipses

• Solar Eclipse
• A solar eclipse occurs when the moon passes
  between the Earth and the sun, blocking the
  sunlight from reaching the Earth.

• Lunar Eclipse
• A lunar eclipse occurs at a full moon when Earth
  is directly between the moon and the sun.

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Solar and Lunar Eclipses
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What is a tide?

• A tide is the rise and fall of water every 12.5
  hours.
• The water rises for about 6 hours and then falls
  for about 6 hours.

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What causes the tides?

• The force of the gravity pulls the moon Earth
  (especially the water on Earths surface) toward
  each other.
• Tides occur mainly because of differences in how
  much the moon pulls on different parts of the
  Earth.

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Spring and Neap Tides

• Spring Tides
• Once a month, at a new moon, the sun, Earth, and
  moon are nearly in a line.
• The gravity of the sun and moon pull in the same
  direction causing a tide with the greatest
  difference between low and high tide.

• Neap Tides
• Twice a month when the Earth and sun are at right
  angles to line between the Earth and moon.
• The sun and moon pulling in these directions
  causes a tide with the least difference between
  low and high tide.

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Class Review

• Why does the moon change its phases as the month
  progresses?
• Why are a day and a year on the moon the same
  length?

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Homework for Tonight

• Page 45
• Key Terms for Chapter 1 Section 2
• Read the Key ideas for Section 2