Eclipses and Lunar Phases

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Eclipses and Lunar Phases
Created by the Lunar and Planetary Institute For
Educational Use Only LPI is not responsible for
the ways in which this powerpoint may be used or
altered.
http//solarsystem.nasa.gov/multimedia/gallery/Ear
th_Moon.jpg
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(No Transcript)
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Preliminary Topics

• Before students can understand the reason for
  phases, they need to understand
• The Moon orbits the Earth
• The Moon orbit at an angle with respect
  to the Earths orbit around the Sun
• The Moon doesnt shine on its own it reflects
  sunlight
• The scale of the Moon and Earths sizes and
  distance
• Please go through Earth and Moon statistics
  before trying to cover the reason for phases or
  eclipses.

Ecliptic plane
Moons orbital plane
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New (couple days)Waxing Crescent (several
days)1st QuarterWaxing Gibbous (several
days) FullWaning Gibbous (several days)3rd
QuarterWaning Crescent (several days)New
Phases Observing and Identifying
http//www.lpi.usra.edu/education/skytellers/moon_
phases/about.shtml
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Phases--Causes

• The Sun shines on the Moon.
• When the sunlight reflects off the Moons far
  side, we call it a New Moon
• When the sunlight reflects off on the Moons near
  side, we call it a Full Moon
• Between New and Full, we see parts of the daytime
  side of the Moon.

Golfball and Blacklight Activity
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Please do NOT use this to teach phases use to
test for comprehension
http//starchild.gsfc.nasa.gov/docs/StarChild/ques
tions/question3.html
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starchild.gsfc.nasa.gov/docs/StarChild/questions/p
hases.html
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Eclipses

• The Sun and Moon occasionally line up so that we
  have an eclipse.
• These eclipses happen every year
• To see a solar eclipse, you need to be on a
  particular part of the Earth

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When the Earths shadow covers the Moon, we have
a lunar eclipse
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Three types of Lunar Eclipses

• Penumbral lunar eclipsethe Moon only passes
  through the penumbra of Earths shadow
• Partial lunar eclipsepart of the Moon passes
  through the umbra of Earths shadow
• Total lunar eclipsethe entire Moon passes
  through the umbra of Earths shadow
• Who on Earth will be able to see a lunar eclipse?

Anyone who can see the Moon (anyone who is on the
nighttime side of the Earth during the eclipse)
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Images from Fred Espenak http//www.mreclipse.com/
LEphoto/LEgallery1/LEgallery1.html
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Why is the Moon red during an eclipse?

• The Earths atmosphere filters some sunlight and
  allows it to reach the Moons surface
• The blue light is removedscattered down to make
  a blue sky over those in daytime
• Remaining light is red or orange
• Some of this remaining light is bent or refracted
  so that a small fraction of it reaches the Moon
• Exact appearance depends on dust and clouds in
  the Earths atmosphere

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Upcoming Lunar Eclipses

• June 26, 2010, Partial lunar eclipse (not visible
  here))
• Dec 21, 2010, Total lunar eclipse visible in US
  just after midnight
• June 15, 2011, Total lunar eclipse (not visible
  in US_
• Dec 10, 2011, Total lunar eclipse (not visible in
  US)
• June 4, 2012, Partial eclipse
• Nov. 28, 2012, Penumbral eclipse

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Solar Eclipses

• When the Moons shadow covers part of the Earth
• Only happens at New Moon
• Three types Annular, Partial, and Total

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Total Solar Eclipse

• Observers in the umbra shadow see a total
  eclipse (safe to view the Sun) can see the
  corona
• Those in penumbra see a partial eclipsenot
  safe to look directly at Sun
• Only lasts a few minutes
• Path of Totality about 10,000 miles long, only
  100 miles wide

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Photo of a Total Eclipse
http//sunearthday.nasa.gov/2006/multimedia/gal_00
8.php
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Annular Solar Eclipse

• When the Moon is too far to completely cover the
  Sunthe umbra doesnt reach the Earth
• Sun appears as a donut around the Moon

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Photos of an Annular Eclipse
http//sunearthday.nasa.gov/2006/multimedia/gal_01
0.php photos taken by Fred Espenak
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Upcoming Solar Eclipses

• July 11, 2010, total solar eclipse not visible
  in USA
• Jan. 4, 2011, partial solar eclipsenot visible
  in USA
• June 1, 2011, partial solar eclipsenot visible
  in USA
• July 1, 2011, partial solar eclipsenot visible
  in USA
• Nov. 25, 2011, partial solar eclipsenot visible
  in USA
• Next solar eclipse in continental USA--May 20,
  2012 (annular)
• Next Total Solar Eclipse in continental
  USAAugust 21, 2017

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Tides

• The Moons gravity tugs on the Earth.
• It pulls the most on the part of Earth closest,
  which raises the atmosphere, the oceans, and even
  the rocks (a little)
• It pulls the least on the part of Earth thats
  farthest, which allows the oceans and atmosphere
  to be further from the Moon (and higher)
• The Suns gravity does the same thing, but to a
  lesser extent

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Tides and the Moon