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Notes on the
Earth, Sun and Moon - how they affect each other
EQ: How do the Earth, Sun
and Moon affect each other?
- The movement of the Earth
and moon in their orbits affect the appearance of moon by blocking different
amount of light from the sun
1) What are the phases of
- The revolution of the moon
around the earth causes it to appear to change shape
- The moon goes through all
phases in 29.5 days (its period of
- The moon does not have
light, it just reflects the sunís light
- When the moon comes
between the earth and the sun, we are in the new moon phase (we see total
- Earthshine is reflected
sunlight on the moon by the Earth.
- As the moon travels from
the new moon (day 1 to about day 14) the amount of the moon we see grows
larger (it is waxing)
- From about day 15 in the
orbit (the Full Moon) we begin to see less and less of the moon (it is
Poem to help you remember
waxing and waning:
As we travel with more light, the waxing moon is
on the right.
When the light gets less and less, the waning
moon is on the left.
What is an Eclipse?
- When the Earth and moon
revolve around the sun they sometimes block out the sunlight and cast a
shadow on the other body.
- The shadow causes an
- Two types, depend on which
body is blocked (in shadow)
- Solar Eclipse-
When the moon blocks the sunlight from the earth (Earth is in the moonís
- During a solar eclipse-
never look at the sun!
- Lunar Eclipse-
When the Earth blocks the sunlight from the moon (Moon is in Earthís shadow)
- The shadows have two
- Umbra- The
small, dark inner shadow
The larger, lighter outer shadow
3) What are tides and how
are they caused?
- Tides are the rise and
fall of the oceans on the earth
- They are caused by the
gravitational pull of the moon on the Earth
- As the Earth rotates
(every 24 hours) the side of the Earth that faces the moon bulges. This
causes a High tide on both the side of Earth that faces
the moon and on the side of Earth that faces away from the
- Low tides occur on both
sides that do not bulge
- At any given shore on
Earth there are always 2 high tides and 2 low tides every 24 hours.
- Spring tides:
highest high tides Ė When the Earth, Sun and moon line up in their
orbits the sunís gravitational pull adds to the moonís and the tides are
much higher (during the Full and New Moon Phases)
- Neap tides:
lowest high tides-During the 1st quarter and last quarter the
Sun and moon are at right angles so the affect of their gravity works
against each other causing the lowest, high tides to occur.
- At the moonís perigee we
will experience the highest high tides and low tides.