What causes the moon to change phases throughout the month? explain

The cause of the moon going throw phases is the amount of sun light hiting it when the moon is on the side of eath farthest from the sun its a new moon and as it works its way back around the earth more sun light hits the moon going to Waxing Crescent then First Quarter to Waxing Gibbous to Full to Waning Gibbous to Third Quarter and back to new moon.

The moon does not physically change its shape. As it orbits the Earth, it goes through phases, and sunlight and shadows create a slightly different look each night. It takes about one month for the moon to completely cycle through its phases