Sun-Earth-Moon System

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Sun-Earth-Moon System

• Ch 20

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Section 1 Earths Motion

• Earth and Sun
• A) Earth is ALWAYS moving (even though we dont
  feel it)
• B) Around the Sun
• 1) Nearest star 150 million km
• away from Earth
• 2) 100 times bigger than Earth
• 3) Mass is 300,000 times greater
• 4) Inside Sun
• Nuclear Fusion nuclei of atoms
• combine releasing HUGE amounts
  of
• energy!
• SMALL part (of Suns
  energy) reaches
• EARTH!

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Sect. 1 Cont.

• C) Earths movement around Sun
• 1) Revolution motion of one object around
  another object.
• 2) Orbit the path an object follows as it
  moves around another object.
• Earths path is not a perfect circle (close
  but not quite) ellipse.
• 3) 365.24 days (Know why we have leap year??
  Make up for that .24!!)
• 4) Earth revolves around Sun because of SUNs
  GRAVITY pulls on Earth.
• 5) Demo ball on string

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Sect. 1 Cont.

• D) Earth ROTATES on its axis.
• 1) Causes day (part of Earth facing Sun) and
  night (part of Earth away from Sun)!
• 2) Rotation is spinning motion.
• 3) Rotation axis line on which an object
  rotates.
• 4) Rotates COUNTERCLOCK wise.

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Sect. 1 Cont.

• 5) Earth rotates from WEST to EAST causing
• Sun / stars / moon to appear to move from East
  to West.
• 6) Earths axis is tilted sometimes tilted
  toward Sun sometimes away.

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Sect. 1 Cont.

• II)Shape of Earth
• A) Sphere causes different parts to receive
  different amounts of Suns energy.
• Equator
• - more direct Sunlight /warmer
• (receives more energy)
• Northern / Southern Hemisphere
• - more spread out / colder
• (receives less energy)

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Sect. 1 Cont.

• B) Earth is Tilted 23.5 degrees
• INFLUENCES our SEASONS!
• III) Seasons
• A) Cause of Seasons combination of
• 1) TILT !!!
• 2) Revolving around SUN
• 3) REMEMBER
• CLOSEST to Sun in WINTER
• FARTHEST to Sun in SUMMER
• TILT is what makes us warmer or
• cooler!

http//www.youtube.com/watch?vDuiQvPLWziQ
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Sect. 1 Cont.

• B) Solstice (Def day when Earths rotation axis
  is the most toward or away from the sun)
• 1) December Solstice (Winter for us)
• Northern Hemisphere shortest day and longest
  night. (Tilted AWAY from Sun)
• Southern Hemisphere longest day and shortest
  night. (Tilted TOWARD Sun)

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Sect. 1 Seasons Cont.

• 2) June Solstice (Summer for us)
• Northern Hemisphere is tilted TOWARD Sun.
• - Longest day and shortest night.
• Southern Hemisphere is tilted AWAY from Sun.
  (Their winter)
• - Shortest day and longest night.

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Sect. 1 Seasons Cont.

• C) Equinox (Def day when Earths rotation axis
  is leaning along Earths orbit neither toward nor
  away from Sun.)
• 1) September Equinox
• Northern Hemisphere Fall
• 12 hours day and night.
• Southern Hemisphere Spring
• 2) March Equinox
• Northern Hemisphere Spring
• 12 hours day and night
• Southern Hemisphere Fall

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Websites

• Teachers Domain seasons
• There is a tutorial on the book website too.

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End Sect. 1

• Assignment
• Worksheets yes due tomorrow!

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Sect. 2 The MOON

• Moon info
• Formation
• Shortly after Earth formed Mars size planet hit
  Earth.
• Sent vaporized rock into ring around Earth.
• Eventually, formed into our Moon.

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I) Moon Info cont.

• B) Surface No atmosphere or liquid water or
  plate tectonics to change surface.
• Craters - bowl shaped dip from space objects
  crashing into the Moon.
• Maria dark flat areas that formed from lava
  hardening.
• Highlands light colored areas w/ craters (too
  high for the lava to cover so no maria there)
  oldest area on moon.
• Rays bright streaks around craters.

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I) Moons Info. Cont.

• C) Moons Motion
• 1) Revolves around Earth in 27.3 days
  gravitational pull of Earth on Moon.
• 2) Rotates counterclockwise around in 27.3 days
  means
• 3) IMPORTANT same side of Moon faces Earth at
  all times!!!
• Side we see NEAR side
• Side we do not see FAR side

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II) Phases of Moon

• Phases portion of Moon lit up by Sun (part we
  see some planets also have phases).
• Waxing Phases increasing light on Moon
• (DRAW!!) Right side lit up
• Waxing Crescent
• 1st Quarter
• Waxing Gibbous
• Full Moon
• Moon Earth Sun in a line

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II) Phases Cont.

• B) Waning Phases light is decreasing
• Left side lit up
• Waning Gibbous
• 3rd Quarter or Last
• Waning Crescent
• New Moon
• No light Earth Moon Sun in a line

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Website
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Assignment

• Worksheets

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Sect. 3 Eclipses and Tides

• Eclipses produced by shadows of Earth or Moon.
• Parts of a shadow
• Umbra
• Darkest part of a shadow
• In the center or middle
• Penumbra
• Lighter part of a shadow (light is partially
  blocked.
• On the sides or outside of the umbra

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I) Eclipses cont.

• B) Solar Eclipse
• 1) Def Moons shadow appears on Earths
  surface.
• 2) Position Earth Moon Sun (New Moon
  Phase)
• 3) Total occurs only for those in Umbra.
• 4) Partial occurs for those in Penumbra.
• 5) Why dont we have one every New Moon?
• Moons orbit is tilted about 5 degrees from
  Earths orbit so they rarely line up for Solar
  Eclipse.

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Website

• http//www.teachersdomain.org/asset/ess05_vid_tota
  leclipse/
• How many people see a solar eclipse?
• Very few Moons shadow is small compared to
  Earth.

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I) Eclipses cont.

• C) Lunar Eclipse
• 1) Def Moon moves into Earths shadow.
• 2) Position Sun, Earth, Moon in a line can
  ONLY occur during Full Moon.
• 3) Total and Partial occur.
• 4) Again doesnt happen every full moon due to
  Moons orbit

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Website

• http//www.youtube.com/watch?vIKQkM474UE0feature
  related
• How many people can see a lunar eclipse?
• Anyone on Earth who can see the moon more than
  can see a solar eclipse.
• How often can one occur?
• About every 6 months.

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II) Tides

• Def
• Daily rise and fall of sea level.
• Bulges of Earths Oceans.
• P. 748 Figure 20 High Low Tide
• Happens twice each day.
• C) Cause
• Moons gravitational pull on Earth.
• Suns gravitational pull has a smaller effect
  causes special ones

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II) Tides cont.

• D) where Moon Suns grav. work together.
• 1) Spring Tides Full New Moon phase E, M, S
  lined up.
• HIGH tides are higher than usual.
• LOW tides are lower than usual.
• 2) Neap Tides S, E, M form a right angle (90
  deg.)
• HIGH tides are lower than usual.
• LOW tides are higher than usual.
• (P. 748 Fig. 21 bottom of page)

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Finished Chapter Whew!

• Review assignment
• P. 753 Copy and do Concept Map (8-15)
• P. 754 (1-10 Multiple Choice)
• P. 755 SENTENCES!! (14, 16, 17)