Title: Solar and Lunar Eclipse
1Solar and Lunar Eclipse
Appropriate for grades (5-9)
Created by Andrew Leech
Students should be able to Understand the
phases of the moon Understand what is actually
occurring during a lunar eclipse Understand what
is actually occurring during a solar eclipse
2 Phases of the Moon
The Moon is a cold, rocky body about 2,160 miles
(3,476 km) in diameter. It has no light of its
own but shines by sunlight reflected from its
surface. The Moon orbits Earth about once every
29 and a half days. As it circles our planet, the
changing position of the Moon with respect to the
Sun causes our natural satellite to cycle through
a series of phases
3Phases of the Moon
The phases of the moon are described to be either
in a full, new waxing or waning state. The order
of the phases over a 29.5 day cycle are as
follows 1. New Moon 6. Waning Gibbous 2.
Waxing Crescent 7. Last Quarter 3. 1st
quarter 8. Waning Crescent 4. Waxing
Gibbous 9. New Moon 5. Full moon
4Phases of the moon
The phase known as New Moon can not actually be
seen because the illuminated side of the Moon is
then pointed away from Earth. The rest of the
phases are familiar to all of us as the Moon
cycles through them month after month. Did you
realize that the word month is derived from the
Moon's 29.5 day period?
5Phases of the Moon
To many of us, Full Moon is the phase of love and
romance. When the Moon is Full, it rises at
sunset and is visible all night long. At the end
of the night, the Full Moon sets just as the Sun
rises. None of the Moon's other phases have this
unique characteristic. It happens because the
Moon is directly opposite the Sun in the sky when
the Moon is Full. Full Moon also has special
significance with regard to eclipses.
6Lunar Eclipse
An eclipse of the Moon (or lunar eclipse) can
only occur at Full Moon, and only if the Moon
passes through some portion of the Earth's
shadow. The shadow is actually composed of two
cone-shaped components, one nested inside the
other. The outer or penumbral shadow is a zone
where the Earth blocks part but not all of the
Sun's rays from reaching the Moon. In contrast,
the inner or umbral shadow is a region where the
Earth blocks all direct sunlight from reaching
the Moon.
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8Lunar Eclipse
Now you might be wondering "If the Moon orbits
Earth every 29.5 days and lunar eclipses only
occur at Full Moon, then why don't we have an
eclipse once a month during Full Moon?". I'm glad
you asked! You see, the Moon's orbit around Earth
is actually tipped about 5 degrees to Earth's
orbit around the Sun. This means that the Moon
spends most of the time either above or below the
plane of Earth's orbit. And the plane of Earth's
orbit around the Sun is important because Earth's
shadows lie exactly in the same plane. During
Full Moon, our natural satellite usually passes
above or below Earth's shadows and misses them
entirely. No eclipse takes place. But two to four
times each year, the Moon passes through some
portion of the Earth's penumbral or umbral
shadows and one of the above three types of
eclipses occurs.
9Lunar Eclipse
During a total lunar eclipse, the Earth blocks
all direct sunlight from the Moon. Astronauts on
the Moon would then see the Earth eclipsing the
Sun. (They would see a bright red ring around the
Earth as they watched all the sunrises and
sunsets happening simultaneously around the
world!) While the Moon remains completely within
Earth's umbral shadow, indirect sunlight still
manages to reach and illuminate it. However, this
sunlight must first pass deep through the Earth's
atmosphere which filters out most of the blue
colored light. The remaining light is a deep red
or orange in color and is much dimmer than pure
white sunlight. Earth's atmosphere also bends or
refracts some of this light so that a small
fraction of it can reach and illuminate the Moon.
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11The Solar Eclipse
12Solar Eclipse
13Solar Eclipse
14Solar Eclipse
15Solar Eclipse
16Solar Eclipse
17Solar Eclipse
18Conclusion
In conclusion, an eclipse is an exciting
phenomenon that can be viewed only at certain
times of the year. A lunar eclipse is simply the
earths shadow covering the moon. A lunar
eclipse can be observed much more frequently than
a solar eclipse due to the fact that it can be
viewed from 50 percent of earth. A solar eclipse
is simply the moons shadow being cast on
the earth. Only a small fraction of earth will
be able to view it because the moon is much
smaller than the earth. Only a very small
fraction will be able to view a total eclipse
along the path of totality.
19Sources
WWW.MRECLIPSE.COM