Which Moon phase shows illumination that is greater than half and increasing toward fullness?

• A. New Moon
• B. First Quarter Moon
• C. Waxing Crescent Moon
• D. Waxing Gibbous Moon

Answer: (D)

The phase being tested is about how much of the Moon’s face is lit and whether that lit portion is growing toward a full Moon. When the Moon is more than half lit and that illumination is still increasing toward fullness, it occurs after the First Quarter and before the Full Moon. That is the Waxing Gibbous phase. So this phase matches exactly: more than half of the Moon is illuminated, and the illuminated portion is growing toward a full Moon. The other phases don’t fit: New Moon has 0% illumination, First Quarter is exactly half, Waxing Crescent is less than half, and Waning Gibbous would be more than half but decreasing toward the New Moon.