Final answer:
The amount of illumination during the Waning Crescent phase is decreasing. It represents the time in the lunar cycle when the moon's visibility is gradually reducing each night until the new moon, where it's not visible at all.
Step-by-step explanation:
The amount of illumination during the Waning Crescent phase is decreasing. This occurs after the full moon phase when the Moon goes through the phases in reverse order. The Waning Crescent phase is part of the lunar cycle where the visible part of the moon is getting smaller each night until it approaches the new moon phase, where the moon is not visible at all.
The cycle of moon phases begins with the new moon, progresses through the waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and ends with the waning crescent before starting over at new moon. During the waxing phases, illumination increases, while during the waning phases, it decreases. Since the Waning Crescent phase comes after the third quarter and before the new moon, it is characterized by a decrease in the illuminated portion of the Moon.