Choose a convenient time in the evening and take your observations at
the same time each
night. This way the rotation of the Earth will return you to
the same orientation in space for each observation; any changes you see
will be due solely to the motion of the moon. It is not crucial
that you observe from the same place each night but you must be sure
of your orientation with
respect to the horizon and the direction of South. The location you
use should have a horizon
relatively free of obstructions in all directions so you can see the
Moon when it is close to the
horizon. If you don't see the Moon, record that fact and why and observe
again the next evening.
Your journal may consist of both a log of each night of your observations
and a discussion. Just remember that you are a professional observer
and will be expected to provide support for your conclusions.
The observing log should contain a record of each observation that you took. A sample log sheet is at the bottom of this page. You must calibrate your recording sheet from S to W and S to E.
Completeness and specificity are very important in your observation
log. Practice making
position measurements so you can be confident that you are being accurate.
If you compile an
incomplete log, you will also find it very difficult to draw good conclusions
and your project will suffer.
One of the difficult things to report accurately is the position of an object in the sky. One technique that works well for locating the position of the Moon is to use the width of your fist held at arm's length as an angle measuring aid. It takes some practice to make this technique work because there is some tendency for one fist to move as you move the other one. Moon positions based upon the average several repetitions will be more reliable than single observations. Accurate observations of position, orientation of lit surface and coverage of surface will be necessary to allow you to correctly describe the changes in the discussion. The astrolabe will give better measurements if used properly but it is not necessary for good results in this project.
Your summary must include both an overall description of what you observed
during the project
and an explanation of why. Plot all positions on one sheet with the
dates observed. Plot all
phases on one page with dates observed. Following are questions you
should consider in your
summery. I, a. Why should you observe at the same time each night?
b. How good was your
data? c. Was motion smooth? d. What could you improve? II, a. Why was
the motion an arc in
the sky? b. Was the arc symmetric about S? III, a. Why did phase change?
b. What was change in
orientation of phase? c. Why did the orientation change?
Date: Time:
Location:
Observing Conditions:
(For example: How clear was it? How many stars were visible? What parts
of the sky were
obscured by clouds? How distinct was the Moon?):
Location of the Object:
Altitude: fists above the horizon.
Direction on horizon to the point under the object: fists from due South
toward East or West
(circle one).
Place the object on this horizon diagram. Also calibrate this chart
by marking the position of
East and West.
For the Moon:
Shade in the portion of the Moon which is visible.
Be sure that your drawing is properly oriented relative to the horizon.
Comments on the observation: