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

What phase is being completed when the moon appears as a crescent during its waxing period?

1. Waning gibbous

2. Full moon

3. Waxing crescent

4. Last quarter

The correct answer is: Waxing crescent

The phase being completed when the moon appears as a crescent during its waxing period is indeed the waxing crescent phase. This phase occurs just after the new moon and before the first quarter moon. During the waxing crescent phase, a small sliver of the moon becomes illuminated by sunlight, creating a crescent shape that continues to grow as it approaches the first quarter. As the moon moves in its orbit, more of its surface becomes illuminated, transitioning ultimately into the first quarter phase. The other phases mentioned are not associated with the waxing crescent. The waning gibbous occurs after the full moon when the moon’s illumination is decreasing. The full moon represents a phase where the entire face of the moon is illuminated, and the last quarter shows half of the moon illuminated but in a diminishing phase leading toward the new moon. Thus, none of these options reflect the early stage of illumination present during the waxing crescent phase, confirming that waxing crescent is the correct identification of the moon's appearance at that time.