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\begin{center}
{\bf\huge Moon Orbit Project}\\
\vspace{0.20in}
{\Large (Check Lab Syllabus for Due Dates)}\\
\end{center}

\begin{flushleft}
{\bf Introduction}
\end{flushleft}

[This lab is a long-term project required for {\bf SOME SECTIONS} of Astronomy 
110, not all--make sure your TA specifically has asked you to do this exercise---or
you will be wasting needless time and energy for something that is not 
required by all Ast 110 sections! ]

Over a {\bf two month} period you should observe the Moon's 
position every other day.  This lab is worth {\bf two} regular lab grades and
should be taken very seriously!

The goal of this lab is to determine the orbital period and direction of the
orbit of the Moon
via direct observations.  You will also gain a fundamental understanding as to
why the Moon has
phases, and what causes them.  During the lab, always try to picture your
position on the Earth
relative to the Sun and Moon.  Develop in your mind a 3-dimensional view of
what is happening.

The observations you will be making are very similar to those the ancient
peoples made
when determining dates of festivals, planting times, etc.  The observations
only take a few
minutes each day and can be done from any location in the Northern Hemisphere.

Follow the directions below and take very accurate measurements.  It is very
important
that you take regular observations.  Bad weather may prevent you from taking
some observations.
If you procrastinate, you may not be able to take the required number of
observations (25-30)
and you will be graded down.  Don't let this happen to you!  Make observations
whenever
possible.  Come in early for help if you get confused.

\begin{flushleft}
{\bf General Instructions}
\end{flushleft}

Please read all the instructions before beginning your Moon Orbit project.\\


\noindent
1.  Weather permitting, make an observation every other day.  If you miss a
day, then make
observations on two consecutive days.\\

\noindent 
2.  The lab TA will tell you when the moon will be up for the first week, but
after that you
should be able to determine when you can make an observation.\\

\noindent
3.  Take VERY careful measurements.\\

\noindent
4. Make your altitude measurement (the angular distance of an object above
the horizon) using a protractor or the fist method 
described in class, being sure to keep a level base.\\

\noindent
5. Record your observations in the table provided - using extra sheets if 
necessary.\\

\noindent
6.  {\bf HINT:} Go out at different times to make your observations.  The moon
IS ALSO UP during the daytime! Spread your observations around, don't go out 
at the same times every month.\\

\noindent
7.  After about 5 observations, try plotting your data and see your TA if you
think your points are bad, or if you are having problems.\\

\noindent
8.  {\it All observations should be plotted on the same piece of paper.}  Work
through the directions below for plotting your data.  Make sure you understand 
how to make your drawing.  Come in for help right away if you have problems 
making the plot.  \\


{\it Remember that your TA will know if your moon observations are real! }

\begin{flushleft}
{\bf Directions for plotting lunar data}:
\end{flushleft}

(Please use a pencil when constructing the plot)\\

\noindent
1) Begin by drawing a small circle (no bigger than an inch across) in the middle
of a piece of paper.  This will be the Earth. Draw a much larger circle
centered on the Earth. This will represent the orbit of the Moon.\\

\noindent
2) Make a choice for the direction of the Sun (usually off to the right). 
Indicate near the edge of the sheet the direction that light rays from the Sun
would be traveling.\\

\noindent
3) Shade the Earth as it would look if you were in space above the North Pole,
looking down at the Earth.  Make the night side, the side opposite the Sun,
the dark side.\\

\noindent
4) From the view above the North Pole, the circle you drew is the Earth's
equator.  If someone were standing on the equator, you would see them standing
on the circle.  The person's location helps tell you what time it is.  For
example, at noon, the Sun would be directly overhead; it's rays directed
straight down on the person.  On your Earth circle, indicate 6am, 6pm, 12pm
(noon) and 12am. You can now think of the Earth sketch as a clock.  \\

\noindent
5) Pick an observation of the moon on a given date.  Locate the position on the
Earth where you would be at this time. Draw a line from that point of time to
the center of the Earth (radius line).\\

\noindent
6) Draw in a line perpendicular to the radius line you just drew.  This will be
your horizon.  You can see objects above this line, but not below it.  Why?\\

\noindent
7) Determine the eastern and western horizons and label them.  Remember that the
Earth rotates counter-clockwise if you are looking down from the North Pole
and that the direction of rotation is east. East is counter-clockwise on the
Earth circle and West is clockwise.\\

\noindent
8) Using your observed altitude of the Moon as an angular measure, plot this
angle above the eastern or western horizon (as you saw it) using a protractor.
Extend the line from the horizon out to your Moon orbit circle.  \\

\noindent
9) Put a small circle at the end of this line (the Moon) and shade it as it
should appear from your vantage point in space above the North Pole.\\

\noindent
10) Next to the moon you just drew, sketch the moon showing the phase you 
actually saw.  You should check that the phase makes sense with where the Moon 
is on its orbit and how one would see the Moon from the Earth's point of 
view.  Write down the date next to the Moon you've just drawn.  \\

\noindent
11) Repeat the above for several of your observations. Your final drawing 
should contain at least 15 moons of all different phases.  \\
\clearpage
\begin{figure}[!ht]
\begin{flushleft}
\centering
%\caption{The Constellation Cygnus}
\includegraphics[trim=10 0 0 40,clip,scale=0.95]{MOONORBIT/moonex.eps}
\end{flushleft}
\end{figure}
\clearpage

\begin{flushleft}
{\bf Questions}
\end{flushleft}

\noindent
When you have put all your observations on your plot, determine the following
from your plot:\\

\noindent
a) How long does it take for the Moon to go around the Earth once?\\
\noindent
b) In which direction does the Moon orbit the Earth?\\
\noindent
c) Do you have any observations which don't fit the general trend?  What could
have caused these ``bad data points?''\\

Create one final page with observations that cover all of the Moon's phases. It
is NOT necessary
to plot ALL of your data. Strive to make an accurate picture of your
observations. All
observations however must be in your Moon Data Log.\\

\clearpage
\begin{center}
{\bf A Guide to Finding East \& West}
\end{center}

\noindent
Here we try to help you visualize where East \& West are on your Moon diagram.{\bf }

\begin{figure}[!ht]
\begin{center}
\centering
%\caption{The Constellation Cygnus}
\includegraphics[scale=0.68]{MOONORBIT/earth.eps}
\end{center}
\end{figure}

Above is an image of the Earth viewed from a position well above 
the North Pole (the white area near the center!). Locate North America in 
this picture.
One can make out the outline of the East and West coasts of the United States 
as well as the Great Lakes, and much of Mexico, including Baja California. 
Part of Alaska is still in darkness. Now, let us 
travel Eastward from California to Florida. On this image that 
direction (the short way!) is COUNTER-CLOCKWISE.  Therefore, if one
draws an arrow around the globe in a counter-clockwise direction, the tip of
the arrow is EAST and the base of the arrow is WEST. Draw a similar arrow
on your Moon orbit plot to help remind you which horizon is EAST and which 
is WEST when you draw your horizon lines.

In the line-drawing on the next page, you can see a view of the Earth from above North
America. In this representation the lines of longitude (that run from the
North to South poles), and the lines of constant latitude (that run in
concentric circles around the poles) are visible. 
The zero point of longitude (that passes through a point near London, England) 
is called the ``Prime Meridian'', while the zero in latitude is the great
circle called the Equator. The North Pole has a latitude of +90$^{\rm o}$, 
while Las Cruces has a latitude of +32.5$^{\rm o}$.
\begin{figure}[!ht]
\begin{center}
\centering
%\caption{The Constellation Cygnus}
\includegraphics[scale=0.68]{MOONORBIT/longlat.eps}
\end{center}
\end{figure}
\clearpage
\begin{center}
\begin{table}
\caption{Moon Observations Data Log}
\begin{tabular}{|l|c|c|c|l|l|l|r|}
\hline
\# &~ ~Date~ ~&~ ~Time~ ~& Horizon & Altitude & ~Phase~ &~ ~Sketch~ ~& Weather  \\
   &              &  (AM or PM) & (E or W)&          &             & & \\
\hline
1  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
2  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
3  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
4  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
5  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
6  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
7  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
8  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
9  &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
10 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
11 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
12 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
13 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
14 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
15 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
16 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
\end{tabular}
\end{table}
\end{center}
\clearpage
\begin{center}
\begin{tabular}{|l|c|c|c|l|l|l|r|}
\hline
\# &~ ~Date~ ~&~ ~Time~ ~& Horizon & Altitude & ~Phase~ &~ ~Sketch~ ~& Weather  \\
   &              &  (AM or PM) & (E or W)&          &             & & \\
\hline
17 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
18 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
18 &              &             &         &          &             & & \\
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\hline
19 &              &             &         &          &             & & \\
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\hline
20 &              &             &         &          &             & & \\
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\hline
21 &              &             &         &          &             & & \\
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\hline
22 &              &             &         &          &             & & \\
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\hline
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\hline
24 &              &             &         &          &             & & \\
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\hline
30 &              &             &         &          &             & & \\
   &              &             &         &          &             & & \\
\hline
\end{tabular}
\end{center}

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