Why does the Moon change appearance throughout the month?

The Moon goes through "phases." That means it appears to us differently each night during its one-month orbit around our planet. We use terms like "Full Moon," "First Quarter," and "New Moon" to describe how the Moon appears (which we can't see because the lit side is facing away from us).

The Moon does not produce its own light. Sunlight reflected off the Moon's surface is referred to as moonlight. As the Moon orbits Earth, the Sun illuminates the side of the Moon that is facing it. It's always a full Moon to the Sun! If you were looking down on Earth and its Moon from far above the North Pole, you would see a Moon that looked something like this:

However, we can see the Moon from the canter of its orbit. As a result, we see different parts of the Moon's lit side.

Make Moon phases out of Oreos.

Then, to make the four major phases of the Moon, open up some Oreo cookies and scrape off the creme filling.

These Oreo "Moons" depict how the Moon appears from Earth during the following phases:

New Moon:
First Quarter:
Full Moon:
Third Quarter: