Hillsborough Community College Earth Moon Star Worksheet earth science lab exercise. Must follow instructions on the lab manual in order to answer the lab

Hillsborough Community College Earth Moon Star Worksheet earth science lab exercise. Must follow instructions on the lab manual in order to answer the lab questions. Must fill out the blanks using the lab manual, then scan it back to me. There is no additional sources, besides the file I’ve uploaded. exercise
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Earth, Moon and Sun Relationships
As the Earth is rotating the Sun, the Moon is also rotating the Earth. The relative positions of the Earth, Moon and
Sun system changes the view we get of the Moon known as the Moon’s phases. As you may know, the gravitational
force exerted on the Earth by the Moon is the primary reason for tidal fluctuations. In this exercise we will explore
how and why the moon phase changes, and how the Earth, Moon, and Sun system affects tidal patterns on Earth.
I. The Earth, Moon and Sun System
As we already know, the revolution of the Earth
around the Sun, combined with the tilt of Earth’s axis,
creates seasonal changes on Earth. We cannot,
however, forget about our nearest neighbor in space;
the Moon. The Moon is an important aspect of life on
Earth. The Moon’s gravitational pull is what creates
our tides, which is very vital to ecosystems.
Since ancient times, man has gazed at the Moon with
wonder, and noticed how the portion that was lit up
changed in an ordered and timely pattern. These
Moon Phases where used to create our first
calendars. To understand why these changes occur
we’ll have to understand the Earth, Moon and Sun
system. First, the Moon rotates on its axis just like
Earth does. In fact, it rotates at the same rate of speed.
Therefore, the same side of the Moon is always facing
Earth. This is why the “face” of the moon never
changes.
and this is termed the 1st Quarter Moon. As it
continues to wax, only a small crescent shaped
portion on the left will be dark. This is called a
Gibbous Waxing Moon.
When waxing is complete, the Moon will be full.
From this position its revolution will cause the lit
portion to begin to move away from Earth and the
dark portion will now fill in from the right to left.
This is known as Waning.
At first, only a small crescent shaped portion on the
right will be dark; known as a Waning Gibbous
Moon. Eventually the entire right side will be dark. At
this point ¾ of the Moon’s phases have been
completed, and this is known as a 3rd Quarter Moon.
Finally, as the Moon continues to wane, only a small
thumbnail shaped portion will be lit on the left side.
This is known as a Crescent Waning Moon. When
the crescent is completely gone, we are back to a new
Moon.
As the Moon continues its revolution from the new
moon position, the lit side of the Moon will begin to
reveal itself from the right side. The lit portion will
continue to grow from right to left throughout the
coming weeks. This is termed Waxing (think of
adding wax to the Moon).
During the waxing stage the moon will first appear
with only a small lit portion on the right that
resembles a thumbnail. This is known as a Crescent
Waxing Moon. When the right half is completely lit
the moon has gone through one quarter of its phases;
Sun’s Rays
While the Moon rotates, it also revolves around the
Earth. During the path of this revolution the angles
between the Earth, Moon and Sun change; resulting in
the variations in the portions of the Moon that we see
lit. When the Moon is directly opposite the Sun in
relation to the Earth, the entire Moon will appear lit,
known as a Full Moon. When the Moon is on the
same side as the Sun in respect to the Earth, none of
the Moon is lit, known as a New Moon.
Figure 1: Moon Phases. The outer ring is how it
would appear from space and the inner ring is how it
would appear from Earth.
II. Synodic and Sidereal Months
The time it takes the Moon to go through an entire
cycle of phases (IE new moon back to new moon) is
29.5 days, known as a Synodic Month. This is the
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basis of a calendar month (or “moonth”). Although it
takes 29.5 days to complete the Moon’s phases; it
actually only takes the Moon 27.5 days to make a full
360° revolution around the Earth. This is called a
Sidereal Month (the “real” amount of time for a
revolution).
The reason for the almost two day difference is
because while the Moon is revolving the Earth, the
Earth-Moon system is also revolving the Sun. This
varies the angles between the Earth, Moon and Sun
requiring two extra days to finish the Moon’s Phases.
Orbit of the
Moon
Diagram not to scale
Figure 2: An exaggerated example of how the
positions of the Earth and Moon change during the
revolution of the Earth-Moon System around the Sun.
III. Eclipses
In most cases the angles don’t line up exactly perfect
and only part of the Moon or Sun is obstructed called
a Partial Eclipse, but on that very rare circumstance
they line up perfectly where the entire Moon or Sun is
obstructed it is called a Total Eclipse. For years
humans have witnessed these strange phenomenon
and created many superstitious beliefs about them.
These superstitions continue to today.
IV. Tidal Bulges and Tidal Patterns
The gravitational pull of the Moon on the Earth’s
oceans causes the tides. This you may
know, but there are other forces at work
here. In space you must think of the
Sun
Earth and Moon as a system. This
system has its own center of mass. As
the system rotates, centrifugal forces are
created which work to pull the water
towards the outside of rotation. This is
very similar to spinning a bucket of
water around in a circle. The centrifugal
forces force the water to the bottom of
the bucket. On the side of the Earth that
Orbit of
faces the Moon the gravitational forces
Earth
of the Moon are high due to the close
proximity. Centrifugal forces are low
because it is at the center of rotation.
This leads to a net force towards the
Moon creating the tidal bulge towards
the Moon. On the side of the Earth
opposite the Moon the centrifugal forces are high
because it is on the outside of rotation. Due to the
greater distance to the Moon the gravitational forces
of the Moon are low. This leads to the tidal bulge
opposite the Moon.
You might be wondering at this point why we don’t
see more eclipses of the Moon and Sun. After all the
Earth, Moon and Sun line up twice every month.
Shouldn’t they cause eclipses? One has to remember
that the sky is very large, and there are many angles
to deal with that change throughout the year, month
and day and change with your location on Earth. It is
a rare circumstance that the three line up perfectly to
cause an eclipse, but it does happen.
When the Earth passes between the Moon and Sun at
the perfect angle where the Earth’s shadow covers the
Moon this is called a Lunar Eclipse. When the Moon
passes between the Earth and Sun at the perfect angle
where the Moon blocks out the Sun this is called a
Solar Eclipse.
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Figure 3: Forces acting on the Earth-Moon System
resulting in two tidal bulges (not to scale)
As the Earth rotates on its axis and the Moon revolves
around the Earth, these bulges will always face
towards and away from the Moon. This is what
causes the daily tidal patterns we see on Earth. When
the tide is rising from low to high this is termed the
flood current, and when the water is falling from
high to low tide it is termed an ebb current.
There are many
factors that can
contribute to the
tidal patterns present
in any location on
Earth,
like
topography of the
coastline,
surface
ocean
currents,
proximity to land
masses, prevailing
winds, and so on.
The result of all
these factors in a
region will produce
one of three major
tidal patterns. When
a location typically
receives one high
tide and one low
tide every day it is
said to have diurnal
tides. If a location
has two high tides of
about the same
height and two low
tides of about the
same height every
day it is said to have
semidiurnal tides.
If a location has two
high tides and two
low tides every day,
but they vary in
height, it is said to
have
mixed
semidiurnal tides.
V. Spring and Neap Tides
While the Gravitational pull of the Moon is the most
important factor contributing to the tides on Earth, the
gravitational force of the Sun is important as well.
The Sun may be extremely far away, but it has a huge
mass. Therefore, it still does affect the tides on Earth.
When the Earth, Moon, and Sun line up in a straight
line the gravitational forces of the Sun and Moon
work together to create extreme tidal bulges. This
occurs every new moon and full moon, and is termed
a spring tide. During these times Earth will
experience extreme high tides and extreme low tides,
and a very large tidal range. On the other hand, when
the Earth, Moon, and Sun line up at a right angle the
Moon and the Sun’s gravitational forces work against
one another to create less exaggerated tidal bulges.
This occurs during 1st and 3rd quarter moons, and is
termed a neap tide. During this time Earth
experiences less exaggerated high and low tide, and a
smaller
tidal
range.
Graph 1: Idealized examples of
each of the three major tidal
patterns.
Figure 4: Earth, Moon, and Sun orientations leading
to spring and neap tides
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Table 1: NOAA Tidal chart for Tampa, FL 11/17-11/24, 2010
Table 2: NOAA Tidal Chart for Mobile, AL 11/17-11/24, 2010
Table 3: NOAA Tidal Chart for Myrtle Beach, SC 11/17-11/24, 2010
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Earth, Moon and Sun Relationships
Name: _______________________
EX10 Summary Report Assignments
Date: ___________________
1. Shade in the portion of the Moon that would not be lit. In the outer ring show how it would be viewed from
space and in the inner ring show how it would be viewed from Earth. Notice that the Sun is in a different
position than in the example given in the diagram in the exercise. Label the names of each moon phase and
don’t forget to include waxing and waning.
Earth
Sun
2. Define the following terms in your own words.
a. Sidereal Month:
b. Synodic Month:
_
c. Lunar Eclipse:
_
d. Solar Eclipse:
_
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3. Water rising from low to high tide is termed the (ebb/flood) current, while water falling from high to low
tide is termed the (ebb/flood) current. Circle your answers.
4. You would expect the highest high tides, lowest low tides, and largest tidal range during (spring/neap) tides,
and less exaggerated high and low tides, and lower tidal range during (spring/neap) tides. Circle your
answers.
5. During which phases of the moon would you expect to have neap tides? Why?
6. During which phases of the Moon would you expect to have spring tides? Why?
7. Referring to Tables 1-3, what types of tidal pattern do the cities below exhibit?
Tampa, FL
Mobile, AL
Myrtle Beach, SC
___________________
___________________
___________________
8. On which date is the tidal range the highest in tables 1-3? What might this tell you about the moon phase on
this date?
9. What phase is the Moon in today? Go outside and check. If the sky is obscured or the Moon is not out
check back later and be prepared to answer this question next lab.
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