The Lunar Cycle

| Lunar Cycle Lab | Study Questions | Basic Celestial Phenomena |
| New | Waxing Crescent | First Quarter | Waxing Gibbous | Full |
| Waning Gibbous | Third Quarter | Waning Crescent |

What do you think?

1. Do the Moon's phases result from the Earth blocking the light of the Sun?

2. "O Moon! When I look at thy beautiful face, Careening along through the boundaries of space The thought has quite frequently come to my mind If ever I'll gaze on thy glorious behind." (Ronald Ross) Is this poet correct that we always see only one side of the Moon?

3. In the Rime of the Ancient Mariner, Samuel Taylor Coleridge wrote of... "The horned [crescent] moon with one bright star Within the nether tip." What is wrong with this poetic description?

4. How much of the Moon is always illuminated by the Sun at all times?

5. When the Moon is Full, where is it located (answer the three parts to this question below each with a separate answer). Hint, how far apart in degrees is the Sun from the Moon (as viewed from Earth) in each of these situations: at sunset? at midnight? at sunrise?

6. Henry W. Longfellow wrote that: "In broad daylight, and at noon, Yesterday I saw the Moon..." Is this phenomenon possible? If so, could the Moon have been in its full phase?


The moon phase watch activity takes 2 to 4 weeks, but is an ideal way to begin getting to know the moon!

Discover unsuspected secrets about the moon's phases with the Lunar Cycle Lab (answer key provided). Click here for a primary-school version of the Lunar Cycle activity.

Then examine the web pages describing each lunar phase, and compare them with Crowe, Theories of the World, pp. 12-13.

Related topics:

Check your understanding:


The Fourth Day, Genesis 1:14-19

And God said, "Let there be lights in the expanse of the sky to separate the day from the night, and let them serve as signs to mark seasons and days and years, and let them be lights in the expanse of the sky to give light on the earth." And it was so. God made two great lights--the greater light to govern the day and the lesser light to govern the night. He also made the stars. God set them in the expanse of the sky to give light on the earth, to govern the day and the night, and to separate light from darkness. And God saw that it was good. And there was evening, and there was morning--the fourth day.

"The words 'sun' and 'moon' seem to be avoided deliberately here, since both were used as proper names for the pagan deities associated with these heavenly bodies. They are light-givers to be appreciated, not powers to be feared, because the one true God made them." NIV Study Bible

Lunar Eclipses

Solar Eclipses


Johannes Hevelius, Full Moon engraving from Selenographia, 1647
Courtesy History of Science Collections, University of Oklahoma