AstronomyUnderstanding Moon Phases Name_______________________

Standards

· Predict changes in the positions and appearances of objects in the sky (e.g., moon) based on knowledge of current positions and patterns of movements (e.g., lunar cycles).

Go to the website http://www.moonconnection.com/moon_phases.phtml

Study the diagram and read the text. Answer the following questions:

1. How much of the moon is always illuminated by the sun?

2. Explain how the lunar phases are created.

Define the following terms from reading the text on the website:

3. New moon

4. Full moon

5. First quarter

6. Third Quarter

7. Crescent

8. Gibbous

9. Waxing

10. Waning

Answer the following questions:

11. How long is a synodic period?

12. What is a synodic period?

13. How long is the sidereal/orbital period?

14. What is a sidereal/orbital period?

15. Why are the synodic and sidereal periods different lengths of time?

16. The moon’s orbit is inclined about 5 from the Earth-Sun orbital plane. At certain times, the moon becomes aligned in the Earth-Sun plane. What is the term for these two times?

(A. ______________________B. ______________________C. ______________________D. ______________________E. ______________________F. ______________________G. ______________________H. ______________________E. _____________________________F. _____________________________G. _____________________________)Use the diagram at the top of the webpage to fill in the names of the phases on the following diagram:

(Draw and label the positions of the sun, Earth & moon.) (Draw and label the positions of the sun, Earth & moon.)

(SunlightEarth)Drawing The Phases of the Moon

On the inner ring, shade the circles to show how the moon is lit by the sun at each location. Shade the dark parts with your pencil and leave the lit parts white.

On the outer ring, shade the circles to show how the moon would look when seen from the Earth at that location. Shade the dark parts with your pencil and leave the lit parts white.

Label each moon on the outer ring with the name of the phase.