Phases of the Moon

Introduction to Astronomy
Observation Projects

| Setting Sun | Moon Phases | Astrophotography | Ursa Major | Measuring Earth | Star Count | Meteor Shower | Planet Motion | Moon's Orbit | Star Atlas | Sun Diameter | Variable Star | Sun Spots | Artificial Satellites | Rainy Day Projects | Design Your Own |

II. Phases of the Moon

  1. With the page sideways (i.e., long side horizontal) make a full page drawing of the horizon from east through the south to the west. Make the sketch small enough that you have plenty of room above it to mark the position of the Moon. You will need enough details to be able to accurately locate the Moon on this sketch later. Alternatively you can take several photographs and tape/glue them together to make a panoramic view of the horizon.
  2. For at least 14 days, starting from the date of the new moon carefully sketch the position of the Moon each day on your horizon sketch. You must make each observation at exactly the same time. The time you choose should be between sunset and 30 minutes after sunset, but use the exact same time each night. If you have a few cloudy days here and there don’t worry, just make a note that it was cloudy. For this project to work you must have at least 7 or 8 clear nights during the two weeks. Your sketch must be carefully done showing not only the accurate position of the Moon but also the shape, orientation and size.
  3. As you make your sketch, record the date and time of each observation. Also record the position of the Moon in the sky by giving the direction (west, southwest, south, southeast, east) and the approximate number of degrees above the horizon. (90E is at the zenith, 45E is halfway from the horizon to the zenith, etc.) See your text or course notes for methods of measuring angles with your hand at arm’s length.
  4. Your report should include a general description of your results. In particular, answer the following questions:
    A. What was the general pattern of the motion and the phases?
    B. How far (in degrees) did the Moon move each day?
    C. Which direction do the "horns" of the moon's crescent point relative to the position of the Sun just below the horizon? 
    D. Is it ever possible to see the moon during the day?
  5. Alternatively, you can complete this project for the 14 days starting with the full moon. You will need to make your observations at a fixed time that is about 30 minutes or less before sunrise.


Copyright 2005, Department of Physics, Weber State University, Ogden UT 84408-2508

Revision: 8/23/2003 JES, 1/18/2005 ATJ