Final answer:
The age of the Moon can be determined based on its position in its monthly orbit around Earth.
Step-by-step explanation:
The age of the Moon can be determined based on its position in its monthly orbit around Earth. The Moon moves about 12° in the sky each day, which means it moves about 24 times its own diameter in one day. A day or two after the new phase, when the Moon first appears as a thin crescent, it has moved into a position where it reflects a little sunlight towards Earth. The bright crescent increases in size on successive days as the Moon moves away from the direction of the Sun. Therefore, the age of the Moon can be calculated by measuring the number of days since it appeared as a thin crescent.