When the visible portion of the Moon is getting smaller, the Moon is which phase?

When the visible portion of the Moon is getting smaller, the Moon is which phase?

• A. Waxing
• B. First Quarter
• C. Full Moon
• D. Waning

Answer: (D)

The visible illuminated portion of the Moon changes as it orbits Earth, going through waxing (increasing illumination) and waning (decreasing illumination) phases. If the visible part is getting smaller, you’re in the waning part of the cycle, after the full Moon, as we see less of the lit side each night. This includes waning gibbous, last (third) quarter, and waning crescent phases. So the phase described is waning. Waxing means the illumination is increasing, a first quarter is still waxing, and a full Moon is at maximum illumination, not shrinking.

The visible illuminated portion of the Moon changes as it orbits Earth, going through waxing (increasing illumination) and waning (decreasing illumination) phases. If the visible part is getting smaller, you’re in the waning part of the cycle, after the full Moon, as we see less of the lit side each night. This includes waning gibbous, last (third) quarter, and waning crescent phases. So the phase described is waning. Waxing means the illumination is increasing, a first quarter is still waxing, and a full Moon is at maximum illumination, not shrinking.