Lunar and Solar Eclipses

Lunar and Solar Eclipses

Moon Phases and = Tides

(Earth, Moon, and Sun positions 9= .0)

Phases of the Moon

The moti= ons of the Sun, Earth, and Moon result in the changing appearance of the moon as s= een from the Earth called the Phases o= f the Moon. This motion also re= sults in the occasional blocking of the light from the sun causing Solar and Lunar Eclipses.

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The Eart= h rotates on its axis and revolves around the Sun. The Moon also rotates on its axis = and the moon revolves around Earth. The moon’s rotation and the moon’s revolution around Earth take the same amount of time which is 27.3 days.&nb= sp; Because the rotation and revolution of the moon take the same amount= of time, the same side of the moon is always seen on Earth. The moon does not shine on its own= . The moon shines because the light f= rom the sun is reflected off of the moon. Half of the moon reflects light from the sun as the other half is da= rk just as on Earth when half the Earth is night and half the Earth is day.

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The moon= phases depend on the positions of the Sun, Moon, and Earth. As the moon revolves around the Ea= rth, different portions of the lighted side of the moon are seen. This causes the appearance of the = moon to change from seeing no moon, portions of the moon, or the entire moon. This is known as the Phases of the= Moon. It takes about 29.5 days for the M= oon to complete the cycle of phases. The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth. These different shapes of the moon seen on Earth are called phases.

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New Moon:&n= bsp; The Moon is between the Earth and the Sun. The dark side of the moon is
        =             &nb= sp; seen on Earth as the lighted side of the moon faces the sun. The new
        =             &nb= sp; moon rises and sets with the sun.&n= bsp; The moon is not visible in the sky.=
        =             &nb= sp; Sometimes you can faintly see the new moon because of sunlight is         =             &nb= sp; reflected off Earth onto the moon.&= nbsp; This Earth light is called Earthshine.
        =             &nb= sp; During a new moon, there appears to be no Moon.

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Waxing Phases:= After a new moon, more of the

illuminated half of the Moon can be= seen each night.

A waxing moon means the visible lig= hted side will be

growing larger. <= /p>

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Waxing Crescent:&n= bsp; A thin slice of the moon can be seen on the right side of the moon.<= br> = &nb= sp; The part of the moon you can see is waxing or growing into a

= &nb= sp; crescent shape.

First Quarter: One week after the new moon, &frac1= 2; of the lighted side of the moon can be
        =             &nb= sp;    seen. This is ¼ of the entire sur= face of the moon is visible. The m= oon
        =             &nb= sp;    has travel= ed a quarter of the way around the earth. The lighted side of
        =             &nb= sp;     the moon appears to be the right side of the moon.=

Waxing Gibbous: This is when more than ¼ of the moon is visible. Gibbous means
= &nb= sp; means “humpback” in Latin.

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Full Moon: The lighted side of the moon is seen on Earth as the dark side of the moon
= faces the sun. Half of the entire surface of t= he moon is reflecting light.
= The moon has traveled half of the way around the Earth.

Waning Phases:= After a full moon, less<= /span>

and less of the moon is seen each n= ight.

A waning moon means the visible lig= hted

side of the moon will be growing sm= aller.

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Waning Gibbous:&nbs= p; After a full mo= on, less and less of the surface of the moon can
&= nbsp; &nbs= p; &= nbsp; be seen. A portion of the moon o= n the right side cannot be seen.

        =                =           The portion of the moon that can be seen wanes or shrinks. A
        =             &nb= sp;            smaller section of the moon on the right side cannot be seen as
        =             &nb= sp;            most of the moon to the right side is visible.

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Third Quarter:&nbs= p; This occurs whe= n only one half of the lighted side can be seen. The
= &nb= sp; lighted side is the left side. The moon has traveled three quarte= rs of

= &nb= sp; the = way around the Earth.

Waning Crescent: Just before the new moon, only a small slice of the moon can b= e
= &nb= sp; seen lighted on the left side. A crescent is visible on the left s= ide
= &nb= sp; of the moon.

THE SUN

The Tides=

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Because = the moon is close to the Earth, there is a gravitational attraction between the Earth and the moon. The side of the= moon facing the Earth has a bulge because of the gravitational pull of the Earth= on the moon. The Moon also exert= s a gravitational pull on the Earth and the result is the rise and fall of the oceans as the moon moves around the Earth.= This rise and fall of the oceans is called the Tides. The force of gravity between two o= bjects depends on the masses of the objects and the distance between the objects.<= span style=3D'mso-spacerun:yes'> Tides occur because of the differe= nces in how much the moon pulls on the different parts of the Earth.<= /span>

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High and Low Tides

The ocea= n level at the shore line rises for about six hours and then for the next six hours, the ocean level at the shore line falls.&n= bsp; The rise and fall of the oceans is called tides. The gravity of the moon pulling on= Earth causes the oceans to bulge in two places.&= nbsp; The ocean bulges on the side of the Earth facing the moon and on the opposite side of the Earth facing away from the moon. Each of these bulges causes high t= ides. Lowe tides occur between the two bulges. The Earth rotates on = its axis every 24 hours and the moon’s gravity is pulling on a different = part of the Earth. The result is t= wo high tides and two low tides every 24 hours. Because the moon rises about 50 mi= nutes later each day, the high and low tides are about 50 minutes later each day.=

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Spring and Neap Tides

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Some hig= h tides are higher than other high tides. High tides are higher during a full moon phase and a new moon phase. These higher high tide= s are called spring tides. Spring tides occur when the sun an= d the moon are in a direct line with the Earth.&= nbsp; The sun’s gravity increases the effect on Earth and causes the ocean bulges to be larger than usual. The Earth’s crust is hard enough to resist being pulled into a different shape, but the oceans do change shape.

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Some hig= h tides are lower than usual high tides. High tides are lower than usual during the first quarter moon phase = and the third (last) quarter phase. The gravitational pull on the oceans is partly canceled by the sun’s gravitational pull. These high tides that are lower than usual high tides are called neap tides.

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The dist= ance between the Earth and the moon as the moon orbits the Earth also affects the tides. When the moon is close= r to the Earth, the moon’s gravity pulls on the Earth more. If the moon is at perigee during a= new moon or a full moon, extremely high tides and low tides occur.

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The shap= e of bays, inlets, and the ocean floor can change the flow of water that can aff= ect the height and timing of the tides. The effects of ocean tides can influence water far up rivers. During high tide, the water at the= mouth of a river will flow upstream as the tide comes in. When the tides changes to a low ti= de, the water flows downstream back into the ocean.

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The web = link below will bring you to the tides animation.

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ht= tp://home.hiwaay.net/~krcool/Astro/moon/moontides/TideAni.gif

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The intertidal zone is the land at the seashore that is underwater at high tide and is dry land at low tide. Animals and plants living in the intertidal zone have adaptations to survive in both high and low tides.

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For more information, use the following web link.

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http://home.h= iwaay.net/~krcool/Astro/moon/moontides/

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Solar and Lunar Ecli= pses

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The moon revolves around the Earth. The Earth and the moon together revolve around the sun. From time to time some or all of t= he sun’s light is blocked out. There are two types of eclipses.&nb= sp; They are the solar eclipse and the lunar eclipse. It is the revolution of the moon t= hat causes eclipses.

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Solar Eclipse=

A solar eclipse occurs when a new moon is directly between the sun and the Earth. The sun is eclipsed (blocked) as the Earth moves into the shadow of the moon and the sunlight is blocked from reaching the Earth. A shadow has two parts. The umbra is the small, inner shadow = or the darkest portion of the moon’s shadow and is a cone shape. The penumbra is the larger, lighter outer shadow. Anyone in the path of the umbra sees a total solar eclipse. Only those people in the small reg= ion where the moon’s umbra strikes Earth can experience a total eclipse. = During a total eclipse, the only vi= sible part of the sun is a white glow around the edge of the eclipsing sun. The sky is dark so you can see the= stars and the solar corona (the faint outer atmosphere of the sun). Anywhere in the path of the penumbr= a sees a partial solar eclipse where only part of the sun is blocked out. Because the orbit of the moon is slightly tilted about 5^o (not on the same plane) from the orbit = of the Earth, it is rare that the new moon is directly between the Sun and the Earth. Most months, the moon travels a little above or below the sun in the sky. Because the moon’s orbit is not completely circular, sometimes the moon is farther away from t= he Earth. This is when a thin ri= ng of sunlight appears around the outer edge of the moon. This is called an annular eclipse.=

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&= nbsp; &nbs= p; &= nbsp; Sun---------------------------Moon-----Earth<= /span>

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Lunar Eclipse

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A lunar eclipse occurs when the Ear= th is directly between the sun and a full moon.&= nbsp; When the Earth passes through the moon’s shadow, a lunar eclip= se occurs. There is a total lunar eclipse when the moon moves through the umbra, and there is a partial lunar eclipse when the moon passes through the penumbra. Sometimes sunlight bent through Earth’s atmosphere results the eclipsed moon to appear red as the interaction of the molecules with the sunlight filter out the blue light allowing the red light through to light up the moon. A total lunar eclipse can be exper= ienced by those on the night time side of the Earth if the moon is not hidden by clouds. When the Earth, the moon, and the s= un are not quite in line, a partial lunar eclipse occurs as the moon passes partly into the umbra of Earth’s shadow.

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= &nb= sp; Sun--------------------------Earth-----Moon

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