Motion and Phases of the Moon

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Motion and Phases of the Moon
4.02-3
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• The Moon appears to rise in the East and set in
  the West.
• This apparent motion of the moon is caused by the
  rotation of the Earth.

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• The Moon revolves or orbits around the Earth with
  an orbital period of 29.5 days, hence the origins
  of Months of the year.
• As it orbits the Earth, the Moon always has the
  same side facing towards us.

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• Sometimes the Moons orbit is such that it comes
  directly between the Sun and the Earth, blocking
  the path of sunlight to part of the Earth.
• This is called a solar eclipse.

The moons shadow only falls on a small part of
the Earth, and only people standing there can see
the total eclipse.
In the eclipse of 2005 above, who saw the total
eclipse, people in Nunavut or people in Guyana
(South America)?
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• In a full solar eclipse, all that can be seen of
  the Sun is its corona.
• It is dangerous to look directly at a solar
  eclipse, because it may damage the retinal cones
  of your eye.
• Note on the side
• Solar eclipses only last a few minutes, but must
  be observed though special filters to reduce the
  Suns powerful radiation.

The next total solar eclipse seen in Canada will
occur in 2024!
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• In a lunar eclipse, the Earth blocks the Suns
  light from reaching the moon, so the Earth casts
  a shadow on the Moon.

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Recap

• Lunar Eclipses When the earth blocks sunlight
  from reflecting off of the moon.

• Solar Eclipses When the moon comes between the
  sun and us, allowing only a halo to be seen.

Sun From Earth
Earth From Space
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• We are able to see the Moon because it reflects
  the Suns light.
• Only half of the moons surface can be
  illuminated at any one time.

Suns light rays
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• As the relative position of the Moon, Sun and
  Earth change over the period of one month, the
  amount of the Moons surface that can be seen
  from the Earth varies.

Stop frame animation over a whole month

• This results in the various
• phases of the Moon.

The Phases of the Moon (602 min)
http//www.youtube.com/watch?v0vXWXqGmPCkfeature
related History Channel (316 min)
http//www.youtube.com/watch?vnXseTWTZlksfeature
related Good recap Why does the moon look like
it changes? (210 min) http//www.youtube.com/watc
h?vYdI1aDjWLlYfeaturerelated Note Good
explanation, but backwards (moon goes
counterclockwise, not clockwise) Phases of moon
(225 min) http//www.youtube.com/watch?v2aFGNGE
cDOk
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• (The expression once in a blue moon refers to
  something that happens rarely. A blue moon occurs
  when the Moons phases are timed so that there
  are two full moons in one month.)

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Phases of the Moon, What do we see from Earth?
Think before you copy, look at how many days into
the lunar cycle each image represents.
7 Days
14 or 15 Days
Closest to the Sun
22 Days
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Phases of the Moon