Earth and its Moon

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Earth and its Moon
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I. Earths Moon
A. The moon is 3476 km in diameter (about 1/4
the earth).
B. The gravity of the moon is about 1/6 the
Earths gravity.
C. The moons average distance is 384,403km
(about 242,000 miles).
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D. The oldest moon rocks are dated at 4.6
billion years old (about the same as Earth).
E. The temperature ranges from -100C to
-175C (about -400F to 300F)
F. Many craters were made by meteorites because
the moon lacks an atmosphere. These are named
after famous scientists like Copernicus.
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G. The dark areas that appear on the moon are
called Maria, these are the low lands.
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MOON - CONTINUED
H. The moon goes through all of its phases
every 29.5 Earth days.
I. Solar Eclipse occurs when the moon comes
directly between the sun and the Earth. (rare)
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J. Lunar Eclipse occurs when the Earth comes
directly between the sun and the full moon. (more
common)
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Umbra inner shadow of an eclipse.
It is more common to see the penumbra in an
eclipse.
Penumbra outer shadow of an eclipse.
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II. The Moons Motions
A. Perigee - When the moon is closest to the
Earth in its orbit (about 350,000km).
B. Apogee - When the moon is furthest from the
Earth (about 400,000km).
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C. The moon rotates once on its axis every
27.3 Earth days, this is the same amount of
time it takes to revolve around the Earth.
D. The moons period of rotation and
revolution are the same.
E. The same side of the moon always faces the
Earth.
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F. The gravitational attraction between the
Earth and the moon causes the rise and fall of
the oceans known as Tides.
G. The moons gravity causes the oceans to
bulge in two places on the side of the
Earth facing the moon and on the side facing
away from the moon. High tide and low tide
occur twice daily.
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III. The Earth, The Moon, and the Sun
A. The different shapes of the moon are called
Phases of the Moon.
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1. Full Moon
2. Waning Gibbous
3. Last Quarter
4. Waning Cresent
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5. New Moon
6. Waxing Cresent
7. First Quarter
8. Waxing Gibbous
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SEASONS
A. If you could look at The Earth from above
the North Pole, you would see that it rotates
counter clockwise.
B. The Earths axis is tilted at an angle of
23.5.
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C. If the Earths axis was straight up and
down
1. There would be 12 hours daylight, and 12
hours darkness.
2. There would be no seasons (spring,
winter, summer, fall).
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Seasons - continued
D. As the Earth revolves around the sun, the
tilt on the axis causes the seasons.
E. The hemisphere tilted toward the sun
receives more direct sunlight. Longer days
plus more sunlight causes summer and the other
seasons.
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Vernal (spring) equinox March 20/21
Autumnal Equinox Sept. 22/23
Winter solstice Dec. 21/22 - shortest day of
year for us
Summer solstice June 20/21 - longest day of
year for us