Earth-Moon-Sun Relationship
Earthshine Project, BBSO (http://www.bbso.njit.edu/espr/fig10.html
Earth-Moon-Sun Relationship
Sphere – a round, three-dimensional object
whose surface at all points is the same distance
from its center
Axis – an imaginary line around which an object
spins
Earth-Moon-Sun Relationship
Rotation – the spinning of an object around its axis
Revolution – the orbiting of one object around another,
like Earth revolving around the sun
Ellipse – an elongated, closed curve; the shape of
planetary orbits
Why do we have Seasons?
They are caused by the tilt of Earth’s axis, 23½0
Equinox – when the noon sun is directly overhead at
the equator, equal hours of daylight and darkness
Solstice – when the noon sun is directly overhead at
either 23½0N (Tropic of Cancer) or 23½0S (Tropic of
Capricorn) latitude, coincides with the 1st day of
summer or winter
Great sites….
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http://esminfo.prenhall.com/science/geoanimatio
ns/animations/01_EarthSun_E2.html
http://www.astro.uiuc.edu/projects/data/Seasons/
seasons.html - seasons
http://www.instruction.greenriver.edu/physics/sea
sons/seasonsgraph.html -seasons
http://aa.usno.navy.mil/data/docs/earthvie
w.php - day and night
Path of the Ecliptic
The apparent path of the Sun across the sky.
In summer, the Sun's path is longest, and so are the days.
In winter, the Sun's path is shortest, and so are the days.
http://www.lon-capa.org/~mmp/applist/seasons/cd190b.htm
The Moon
1.
2.
3.
4.
Earth’s only natural satellite
384,000km away, 1/6th the gravity of Earth
Noon temp. of 1300C, night temp. of -1750C
Surface features
1.
2.
Dark, flat plains called marias
Bright areas called highlands
The Moon (cont.)
The period of rotation equals the period of
revolution around the Earth
Apollo 11 put Neil Armstrong and Edwin “Buzz”
Aldrin on the moon on July 16th, 1969
The Moon (cont.)
Lunar Eclipse – when Earth passes between the
moon and the sun
The Moon (cont.)
Solar Eclipse – when the moon passes between
Earth and the sun
Earth-Moon
Revolutions
The earth and moon
revolving around
the barycenter.
Notice how the
earth moves
slightly.
Tides
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http://www.meted.ucar.edu/oceans/tides_intro/menu.htm
https://www.meted.ucar.edu/oceans/tides_intro/media/graphics/lunardecexplain.gif
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Caused by moon’s gravitational pull
Spring Tide – the moon, Earth and sun align
Neap Tide – when the moon, Earth and sun
form a right angle
Moon Phases
Changes in appearance of the moon as it orbits Earth
every 29½ days
New Moon – when the side facing Earth is totally dark
First Quarter Moon – when the right half of the moon
facing Earth is lit
Full Moon – when the side facing Earth is completely lit
Third Quarter Moon – when the left half of the moon
facing Earth is lit
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Why do we NOT have a Lunar Eclipse
every month?
Earth’s magnetic field
Basically a ‘magnet’,
exerting a magnetic
field surrounding the
earth, which
effectively extends
several tens of
thousands of
kilometers into
space, is called the
magnetosphere.
Magnetosphere protects us from the Solar Wind.
http://averyhenderson.files.wordpress.com/2008/12/solarinteraction1.jpeg
Earth’s Magnetic Field
What is Solar Wind
A stream of energized, charged particles,
primarily electrons and protons, flowing
outward from the Sun
 Travels through the solar system at
speeds as high as 400-900 km/s (and at a
temperature of 1 million degrees (Celsius).
 Made of plasma.
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http://www.aerospaceweb.org/question/astronomy/magnetic-field/earth.jpg
Extra Credit….
Go online and find:
The phase that the moon was on MY
birthday – May 1st.
The phase of the moon on YOUR birthday
The month and year of the next
BLUE MOON