How to Fill in the Observation Sheet

You are responsible for all things herein!!! You'll lose points if you don't do this stuff.

Here is the sheet from the manual (.pdf file. Acrobat Reader required).


Date column:

- This is the date that you recorded for each observation. It is very important so do not forget to write it down when you make an observation.

Clock Time column:

- This is the time that you record for each observation according to your watch (which you should make sure is correct). You must write down A.M. or P.M. If you don't, I will have no idea which one you are talking about. Do not make any adjustments for Daylight Time here, just write down the current official time.
 

Decimal CST column:

- CST stands for 'Central Standard Time' and for this you are required to have it on the 24-hour clock (military time). Therefore, if you observe at clock time of 9:30 p.m. you will have to convert. To do this, just add 12 to the hours after noon.

9:30 p.m. + 12 = 21:30          6:30 a.m. = 06:30          12:45 a.m. = 00:45

- You must make sure you are in standard time as well. When we are in Daylight Saving Time (starting 2 a.m. March 8), you have to subtract one hour from ALL OF YOUR TIMES (not just the ones you added 12 to).

21:30 - 1 = 20:30          06:30 - 1 = 05:30           00:45 - 1 = 23:45
  As you can see, observations made between midnight and 1 a.m. "wrap around" the 0/24 hour mark back to 23 hours.

- You MUST also convert your minutes into decimals - this will help you when you make calculations. I'll give you a few examples:

20:30 will be 20.5 (as 30/60 = 1/2 = 0.5)          00:45 will be 00.75 (as 45/60 = 0.75)          06:10 will be 06.17 (as 10/60 = 0.167)
(max of 2 digits after decimal!)

Phase Sketch column:

- Draw what you saw. Try to be as accurate as possible of what percentage of the moon is lit (crater detail is not needed, only illumination).
 

Phase Number column:

- I highly encourage you to use decimal phase numbers for the 'in-between' phases. By doing this, you will end up with better results on the graphs you will do for your final project.

the moon is not quite full = phase 3.8
the moon has just passed 3rd quarter = phase 6.1

Hands/Fists column:

- Don't know how to take an observation? Either check back to Lab D: Observing The Moon or read this section.

- Write down how many fists East (left) or West (right) of South you measured the Moon's position.

- Make VERY sure that you record the direction you went - either to the right or the left of south (left [East] = negative)

Moon's H.A. column:

- The Moon's HA column should have the number of degrees the moon is away from south. To convert:

my hand spans 15 degrees, my fist 10 degrees
observation 1: moon 4.0 hands right (West) of south  --> 4.0 hands * 15 degrees per hand = 4 * 15 = 60 degrees
observation 2: moon 2.3 hands left (East) of south  -->   -2.3 hands * 15 degrees per hand = -2.3 * 15 = -34.5 degrees

Day Number column:

- This is the number of days from the beginning of the year (i.e. January 1st). For example, Jan 1 = Day 1, Jan 2 = Day 2, Jan 31 = Day 31, Feb 1 = Day 32, etc...

You can find any day's day number from this chart.

Sun's H.A. column:
also see Lab G for how to do this

- Sun's Hour Angle is where the sun is in relation to 0 degrees South (just like the moon). Therefore, if the Sun's H.A. is 0, the time is 12 noon (or so)

- The equation goes as this:  [(CST) - 12.0] * 15 = SUN'S H.A.

    You have CST from your observations. It MUST be in the 24 hour clock AND THE MINUTES MUST BE IN DECIMALS (see the third point in the 'CST column' section). If the minutes are not in decimals, your future calculations WILL BE WRONG (and points deducted).
ex: observed at 9:30 pm (CDT) so, CST = 20.5, and 20.5 - 12.0 = 8.5, so Sun's HA = 8.5 * 15 = 128
ex: observed 6:30 am (CDT) so, CST = 5.5 and 5.5 - 12.0 = -6.5 , so Sun's HA = -6.5 * 15 = -98
ex: observed 12:59 am (CST) so, CST = 0.98 and 0.98 - 12.0 = -11.02, so Sun's HA = -11.02 * 15 = -165
example of WRONG: obs at 12:59 am (CST) ~~ so then I (wrongly) say CST = 0.59, so 0.59 - 12.0 = -11.41, so Sun's HA = -11.41 * 15 = -171 -- WRONG

Elongation column:
also see Lab G for how to do this

- The equation goes as this:  (Sun's H.A.) - (Moon's H.A.) = ELONGATION

- You have the Sun's H.A. from above and the Moon's H.A. is what you calculated from your hands/fists. REMEMBER, if Moon's H.A. is negative, keep it that way and when you subtract a negative number, it turns positive.

ex: Sun's H.A. = 128, Moon's H.A. = -13 ~~ Elongation = 128 - (-13) = 128 + 13 = 141
ex: Sun = -5, Moon = -90 ~~ Elongation = -5 - (-90) = -5 + 90 = 85
ex: Sun = -128, Moon = -13 ~~ Elongation = -128 - (-13) = -128 + 13 = -115

- This brings up a situation: ELONGATION MUST BE POSITIVE. If you get a negative number for elongation, then add 360 degrees until you get a number between 0 and 360 (sometimes you may come up with a rather large negative number). Do NOT just change the - sign to a + sign. This rule doesn't apply to H.A.'s, only the elongation.

ex: Elong = -115, so -115 + 360 = 245 degrees

LINKS

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