Moon Project Cheat Sheet
Submit a Moon observation: www.physics.umn.edu/resources/moonproject/observations.html
Check the rise and set times: http://www.40-below.com/sunmoon/index.html
Tips:
 Remember: depending on its phase, the Moon may be out during the day!!
 You will not be able to observe the moon during a new moon. This happens when
the moon rises and sets with the sun. Be sure to check the rise and set times ahead of
time to make sure the moon is out when you try to make an observation.
 Make sure to measure from due south!!
 If you are on the main quad with Northrop to your back, then Coffman is directly south
 On Google Maps north is up
 Take notes. Don’t try to remember the details of an observation
To enter an observation online (these are the same steps for your paper observation
log):
1) Enter the date, mm/dd/yyyy
2) Enter the time you made the observation.
What time did your clock say? If necessary, account for daylight savings time in the
next step
3) Convert this time into decimal Central Standard Time (CST)
1. Change to 24-hour time. If time is PM, add 12 hours. (Midnight = 0, Noon = 12)
2. If it is daylight savings time, subtract 1 hour
We are currently in daylight savings time until Sunday, November 3, 2013.
3. Decimal CST = HH + (MM/60)
4) Phase sketch. Choose an image of the Moon that matches what you saw
In your observing log, color the dark part of the Moon. Keep the illuminated side
white
5) Phase numbers are listed on pg 4 and 44 of your lab notebook. Be as accurate as
possible – use fractions of phase numbers
6) Enter the number of fists you counted. Again, be as accurate as possible – half and quarter
fists (each knuckle is approximately a quarter of a fist!)
7) The Moon HA is the (number of fists) x (degrees/fist)
HA is negative if an object is approaching the meridian (to the East, or to the left if
you’re facing South). HA is positive if the object has already passed the meridian
(west, right)
When entering online, keep the value positive and choose “(-) East” or “(+) West”
8) Enter the day number. Use the chart on pg 7
9) Sun HA = (CST(in hours) – 12) x 15 (degrees/hour)
10) Elongation – the angle made between the Moon, Earth and Sun (see pg 46)
Elongation = HA of Sun – HA of Moon
Elongation angle is always positive, tracing the Moon in its orbit around the Earth.
If you calculate a negative elongation, add 360
Deadlines:
Moon I
Moon II
Moon III
3 observations
6 new obs. (9 total)
6 new obs. (15 total) & write-up
Friday, September 27
Friday, October 25
Wednesday, November 27
Keep in Mind:

Enter observations online within 3 days (72 hours)

Observations must be at least 12 hours apart

You need at least 15 observations for full credit

Don’t procrastinate!!
It will behoove you to start as soon as possible and stay on top of it. Weather is
unpredictable. Don’t count on clear skies the week before deadlines. In particular, you
should expect some bad weather towards the end of the semester- so please allow
yourself time for this.
I have set the online system’s tolerance for calculations to 1°. If you follow the formulas in
your lab book (and outlined here), you should have no problem


It’s best to use decimal phase numbers and fist counts

You may try an unlimited number of times to get green boxes for an observation
EXCEPT:
You may not change the number of fists or the observation time, just as you
wouldn’t change the results of an experiment after you ran it. That’s bad science.
If I see this, I will reject the observation.

Even if boxes are green it will be up to my discretion whether or not to accept an
observation

Cheating on this project is easy to catch

Feel free to leave me a comment on an observation, send me an email, come to my (or
any other TA’s) office hours, or talk to me after lab if you have any questions or problems!