The Moon orbits around Earth and Earth orbits around the Sun. Very simple. Now, the angle between the Sun, Moon, and Earth changes constantly. And as a result, the amount of sunlight that reflects off the Moon and travels to our eyes changes every day. This means that the moon does not produce any light and only reflects sunlight.
We can see that the Moon’s disk change from full dark to full light to full dark again: This interval are timely and is called a lunar cycle. Another names for the lunar cycle are lunation, lunar month, or synodic month.
How long does it takes for the moon to change cycles? The length of the cycle will vary, but on average, it is known to be 29.5 days on average.
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