OBJECTIVES & UNDERSTANDINGS

• Locate the horizon and zenith on the Moon Phaser.
• Use the Moon Phaser to determine the current Moon phase and approximate position in the sky for a given date and time.
• Use the Moon Phaser to determine the approximate time of moonrise and moonset for eight moon phases.

MATERIALS (supplied by classroom teacher)

• Moon Phaser (two Adobe Acrobat PDFs): Sheet A; Sheet B (download a free copy of Adobe Acrobat Reader)
• Scissors
• Transparent tape and tape dispenser
• Staples and stapler
• Single-hole and three-hole punches (optional)

PROCEDURE

1. Using the materials provided by the planetarium teacher, construct a Moon Phaser.
2. Answer the following activity questions.

USING THE MOON PHASER

Like the Sun (which is a star), the Moon appears to rise in the east, move across the southern sky, and set in the west (daily motion caused by the Earth's rotation). Facing south, hold the Moon Phaser so that the MOON DIAL is at the top and the "Time Window" is at the bottom.

Determining Current Moon Phase & Approximate Position in the Sky

1. Use the "NEW MOON CALENDAR" (which appears on the Moon Phaser) and a regular calendar to count the number of days since the last New Moon.
2. Find that number (from Step 1 above) on the MOON DIAL--the current Moon phase appears below this number.
3. Decide what time of day or night you will observe the Moon. Then rotate the MOON DIAL so that the time of your observation appears in the "Time Window." If the Moon is visible (i.e., above the horizon) at the time you have chosen to observe, then the current Moon phase is shown in the correct direction (E, S, or W) and position in the sky.

Determining Approximate Time of Moonrise & Moonset

1. For a given Moon phase, rotate the MOON DIAL so that the Moon appears just above the eastern horizon. Note the time which appears in the "Time Window"--this is the time of moonrise. For example, the New Moon (No. 30) rises at approximately 6 a.m.
2. Rotate the MOON DIAL so that the same Moon phase just touches (or is just below) the western horizon. Note the time which appears in the "Time Window"--this is the time of moonset. For example, the New Moon (No. 30) sets at approximately 6 p.m. Note that every Moon phase is visible for approximately a 12-hour period.

ACTIVITY QUESTIONS

1. The horizon is the imaginary line where the sky appears to meet the land. On the Moon Phaser, label the horizon.
   
   
   
2. The zenith is the imaginary point in the sky directly overhead an observer. On the Moon Phaser, label the zenith.
   
   
   
3. On 11 April 2000, which Moon phase would be visible in the sky?
   
   
   
4. Using the Moon Phaser, identify the Moon phase which would appear in the sky for the dates listed in the following table. Record your answers in the table. Then determine if the Moon would be above or below the horizon for the times listed in the table. Answer the question by writing either "above" for phases above the horizon or "below" for phases below the horizon.

   Date & Time	Moon Phase	Above or Below Horizon
   10 May 2000 at 9 p.m.	First Quarter
   18 May 2000 at 9 p.m.
   26 May 2000 at 6 p.m.

5. Explain why every Moon phase is visible for approximately a 12-hour period.
   
   
   

REFERENCE TABLES

Moon Phase versus Moon Phaser Position Number

Moon Phase	Moon Phaser Position Number
New Moon	30
Waxing Crescent	4
First Quarter	8
Waxing Gibbous	12
Full Moon	15
Waning Gibbous	19
Last Quarter	22
Waning Crescent	26

Enhance your Moon Phaser by adding a "Moon Phaser Strip" showing eight named Moon phases versus Moon Phaser position number. (Print at 90%; staple or glue strip to Moon Phaser.)

NEW MOON CALENDAR

Calendar: 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004