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

What phase of the moon occurs when it is completely invisible from Earth?

1. Waxing gibbous

2. Full moon

3. New moon

4. Last quarter

The correct answer is: New moon

The phase of the moon when it is completely invisible from Earth is known as the new moon. During this phase, the moon is positioned between the Earth and the sun, which means that the side of the moon that is illuminated by the sun is facing away from the Earth. As a result, from our vantage point, we cannot see the moon at all, as it blends into the background of the daytime sky. This phase marks the beginning of the lunar cycle and is significant in various cultural traditions and lunar calendars, as it signifies renewal and new beginnings. The other phases mentioned, such as waxing gibbous, full moon, and last quarter, are characterized by varying amounts of the moon's surface being lit and visible from Earth. In the waxing gibbous phase, more than half of the side facing Earth is illuminated but not fully. The full moon is when the entire face of the moon is illuminated, making it bright and easily visible. The last quarter occurs when half of the moon is illuminated, presenting a clear half-circle. Thus, the new moon is distinctly characterized by its invisibility from our perspective.