Which phase is seen after Full Moon when illumination is decreasing but more than half?

Which phase is seen after Full Moon when illumination is decreasing but more than half?

• A. Third Quarter
• B. Waning Crescent
• C. Waning Gibbous
• D. New Moon

Answer: (C)

After a Full Moon the visible illumination is shrinking as the Moon moves toward New Moon. The term waning means decreasing illumination, and gibbous means more than half of the Moon is lit. So the phase seen when the Moon is still more than half lit but the light is decreasing is Waning Gibbous. The other stages don’t fit as well: Third Quarter is exactly half lit, Waning Crescent is less than half lit as it moves toward New Moon, and New Moon has little to no illumination.

After a Full Moon the visible illumination is shrinking as the Moon moves toward New Moon. The term waning means decreasing illumination, and gibbous means more than half of the Moon is lit. So the phase seen when the Moon is still more than half lit but the light is decreasing is Waning Gibbous. The other stages don’t fit as well: Third Quarter is exactly half lit, Waning Crescent is less than half lit as it moves toward New Moon, and New Moon has little to no illumination.