Lunar Phase Watch

| Lunar Cycle Lab | Moon index | Basic Celestial Phenomena |
| New | Waxing Crescent | First Quarter | Waxing Gibbous | Full |
| Waning Gibbous | Third Quarter | Waning Crescent |
| Primary School moon unit | OBU Planetarium |

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• This Phase Watch is best started near the date of a New Moon (to find out when the next New Moon will occur, contact the OBU Planetarium: 878-2090 or email). However, you can start it anytime.
• To complete the Phase Watch requires about 4 weeks, but it may be useful even if observations are carried out for only the first two weeks after New Moon.
• Make all observations at sunset or sunrise.

Procedure

1. Print a copy of the Horizon template. Observe that it consists of two diagrams in one, with the horizon line running down the center. One side shows the horizon at sunset, the other side shows the horizon at sunrise. Fold it in half lengthwise if the two sides are distracting.

    

2. Familiarize yourself with the names of the lunar phases, here given in alphabetical order:

   First Quarter			Waning Crescent
   Full Moon			Waning Gibbous
   New Moon			Waxing Crescent
   Third Quarter			Waxing Gibbous

    

3. On the evening of the New Moon go out and verify that the Moon is not visible in the evening sky. It is actually setting with the Sun in the west, as indicated on the horizon template. Go outside at various times during the night, or before sunrise, to verify that the Moon cannot be seen at any time.

    

4. Watch the area above the western horizon from night to night just after sunset 1 to 4 days after New Moon. The first time you see the Moon draw its phase in the phase box pictured above the western horizon at sunset. Write the name of the phase beneath the phase box.

    

5. About a week after New Moon find the Moon in the sky at sunset. Draw its phase in the box overhead in the south, and write the name of the phase underneath the phase box.

    

6. A few days after the previous observation see what phase the Moon is in at sunset. It will be located above the eastern horizon. Draw its phase in the phase box, and write the name of the phase beneath.

    

7. About 2 weeks after New Moon the Moon will be Full, as shown on the template. When Full, the Moon rises in the east at sunset and sets in the west at sunrise.

    

8. Flip the chart over to use the side depicting the horizon as you face south at sunrise. Ooooh; it will be hard to catch the Moon early in the morning! Nevertheless, 2 to 4 days after the Full Moon, the Moon will be above the western horizon at sunrise. Draw its phase in the box (shown close to "Third Week") and write the name of this phase underneath.

    

9. About 3 weeks after the New Moon, and 1 week after the Full Moon, you will find the Moon overhead in the south at sunrise. Draw and label its phase in the box.

    

10. During the fourth week the Moon will be above the eastern horizon at sunrise. Draw and label its phase in the box. You have now watched the Moon pass through one lunar cycle, or "moonth"! Congratulations!