20 Project: Tracking the Phases of the Moon

Overview: The purpose of Tracking the Phases of the Moon is for students to observe the Moon over a period of time to better understand its phases, positions in the sky, and movements.

Students will observe the Moon at least three times a week during a lunar phase cycle, which will cover all lunar phases.

For each observation fill in columns A-G (described below) on the Tracking the Moon Observations Log (attached for printing). Six copies of the log are provided in the attachment. Copy more of the Tracking the Moon Observations Log as needed; each page will record two (2) separate observations. An example of a completed log is attached. Note that cloudy days and/or nights when the Moon is not visible due to clouds is not considered an observation. However you should note attempts when cloudy; this is part of ‘doing science.’ No New Moon observations accepted, but you may note it.

At the end of the assignment, you will answer a series of questions based on your observations.

Tracking the Moon Observations Log Columns:

  1. Date & Time: Complete date and time; include AM or PM with the time of your observation or the data is incomplete. The Moon will not always be visible in the evening skies; sometimes it is a daytime object, sometimes early morning.
  2. Location: Where you made the observations; there is a space on the form at the bottom for listing and coding observation location. Most will make their observations from home.
  3. Conditions: Note weather conditions at the time of your observation. How much of the sky is covered by clouds? For example: 25% light clouds, heavy clouds, or fog. Or is it totally clear?
  4. Azimuth & Altitude
    • Azimuth is the direction around the horizon; north is 0 degrees, east 90 degrees, south 180 degrees, and west 270 degrees. You might find a compass useful; many smartphones have a compass. Ponder for a moment the direction where the Moon rises and sets? Where does the Sun rise? Sun set? Altitude refers to how high an object is above the horizon. The highest an object can be is overhead or 90 degrees. Objects at the horizon are at 0degrees. One can quickly estimate how far the Moon is above the horizon; halfway up above the horizon is 45 degrees.
    • A simple astrolabe can be used to make altitude measurements. See the attached document, The Astrolabe, for how to make a simple Altitude-Finding Device.
    • There are also a number of smartphone apps to determine direction (compass) and angles; most of these are free and well-worth taking the time to download and use for this assignment. For most people extending the arm and measuring from one side of the extended 10 degrees fist to the other side is close to 10 degrees.
  5. Drawing: Use the circle provided to carefully shade the portion of the Moon that you do not see; a pencil is highly recommended. F. Rising or Setting: How can you tell if the Moon is rising or setting? 50% of the time the Moon is rising or getting higher in the sky. 50% of the time it is setting or getting lower in the sky. Again, think about where celestial objects like the Moon or Sun rise and set. Occasionally the Moon will be at the Meridian… the north-to-south dividing line.
  6. Moon Phase: Note the phase; also note crescent/gibbous, waxing/waning as appropriate. You may also reference the website COMPLETE SUN AND MOON DATA FOR ONE DAY (United States Naval Observatory): http://aa.usno.navy.mil/data/docs/RS_OneDay.php

Answer these questions based on your observations.

  1. How did you measure the Moon’s azimuth and altitude? Describe your procedure.
  2. Based on your observations, give the time when the full Moon rose. Why do you think this occurs at the time you noted?
  3. What was the youngest Moon you saw? The oldest Moon? [The youngest Moon refers to the Moon right after new moon – in the evening sky; the oldest right before new moon – in the morning sky.
  4. Around what time of the day did you best “see” the 1st Quarter Moon? Last Quarter Moon? Did you notice any difference between the appearances of the 1st Quarter and Last Quarter Moon?
  5. What can you say about changes in Moonrise times, from night to night?
  6. What difficulties, if any, did you have with this assignment?

Points & Due Date: This assignment is worth 100 points. Please reference the grading rubric to understand how this assignment will be graded. It’s important to begin this assignment early in the term. It’s due date is dependent on the start and end of an appropriate lunar phase cycle, about 35 days (add five days to allot time to complete the assignment questions).


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