ECLIPSES & TIDEShttp://safeshare.tv/w/KebKsedNAq

Chinese astrologers wrote of an eclipse occurring over 4000 years ago.

Historians and astronomers believe that this was an eclipse that happened on 22 October 2134 B.C.

Two astrologers at the time, Hsi and Ho, had apparently failed to predict this eclipse, and so were beheaded.

• Celestial bodies (planets, moons) are always “moving in front of each other.

• One celestial object casts a shadow on the other

• From Earth we see this as either a solar eclipse or a lunar eclipse

• Eclipses

http://safeshare.tv/w/KebKsedNAq

Solar Eclipses

http://www.youtube.com/watch?v=DSsrIThxeCI

• Solar Eclipse • Solar Eclipse occurs when the Moon blocks the light from the Sun and causes a shadow on a small area of the Earth

• Baileys Beads

• Diamond Ring

Viewing a Solar Eclipse

How We See

Eclipse shadowsWhen the light passes through gaps between leaves of a tree, the shadows on the ground show little copies of the eclipse going on in the sky. In this eclipse, the moon did not quite cover all of the Sun, so you seen white rings. C

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http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2017Aug21Tgoogle.html

Umbra

Path of totality

Eclipse of 2017

Lunar eclipses

http://www.youtube.com/watch?v=wuhNZejHeBg

Lunar eclipse

• Lunar eclipse• Lunar Eclipse• Moon passes through Earth's shadow• Occurs during Full Moon phase

Credit and Copyright: Andy Steere

Fun Eclipse Facts

• The moon’s shadow moves at 1700 km/hour (1,048 mi/hr) .

• Maximum totality is ~7 ½ minutes.• Every place on Earth will see a total solar eclipse once

every 400 years.• Solar Eclipses occur more frequently than lunar eclipses

( by 5:3).• There must be at least two solar eclipses every year.• There can be two solar eclipses in back to back months

with a total lunar eclipse in between.• This triple eclipse will occur twice during an eclipse year

(1935, 2160).• Seven eclipses is the maximum - 4 solar, 3 lunar (1982,

2485).

• TIDES • TIDES- the regular rise and fall of the Earth’s oceans due to the gravitational pull of the moon

http://www.youtube.com/watch?v=rRPtNAA-9UE

Spring tides occur at Full and New Moons

Draw this diagram

• Spring tide • Spring tides – occur during the new and full moon phases

• The direct line of the Sun and moon cause additional gravitational pull (like a tug of war – in a straight line)

• Neap Tide • Neap tides – occur at the quarter moon phases

• Tides are lower

Neap Tides occur at quarter Moons

Draw this diagram

Resources

Paper Plate Astronomy http://analyzer.depaul.edu/paperplate/

Solar Events http://solarevents.org

Eclipseshttp://sunearth.gsfc.nasa.gov/eclipse/eclipse.html

Earth Moon Viewer http://www.fourmilab.ch/earthview/vplanet.html

Lunar Posn Calculator http://www.fourmilab.ch/earthview/pacalc.html

Lunar Phases, etc.http://www.lkwdpl.org/schools/elempath/heavenlymotion/