It's impossible to pinpoint one specific person who "discovered" the moon's phases. It's a phenomenon that has been observed and understood for thousands of years!

Here's why:

* Ancient civilizations: People in ancient civilizations all over the world, from the Egyptians to the Chinese to the Mayans, observed and documented the changing appearance of the moon. They used these observations to develop calendars and track time.

* Natural observation: The phases of the moon are a simple natural phenomenon that anyone can observe with their own eyes. It doesn't require any special tools or knowledge.

* Early astronomy: Early astronomers, like the Greek philosopher Anaxagoras (5th century BC), developed more detailed theories about the moon's phases, but they were building upon centuries of observations and understanding.

So, while no single person can be credited with the "discovery", the understanding of the moon's phases has been a product of human observation and curiosity throughout history.