Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

During which phase is the moon transitioning from full to new?

1. Waning gibbous

2. First quarter

3. Waxing crescent

4. Full moon

The correct answer is: Waning gibbous

The correct phase during the transition from full moon to new moon is the waning gibbous phase. In this phase, the illuminated portion of the moon that is visible from Earth is decreasing after the full moon, which is fully illuminated. This decline continues until it reaches the last quarter phase, and then further until it transitions to a new moon, where the moon is not visible from Earth. The waning gibbous phase begins right after the full moon, characterized by a substantial portion of the moon still illuminated. Understanding the moon's phases involves recognizing how the position of the moon relative to the Earth and the Sun affects the visible light. The other phases mentioned either do not occur during the transition from full to new, like the first quarter, which occurs before the full moon, or they represent phases in different contexts of the lunar cycle.