The moon goes through eight phases in a cycle that repeats every 27 days and 8 hours. The phases are caused by the changing orientation of the moon in relation to the Earth and sun, and the amount of sunlight that reflects off the moon's surface and is visible from Earth. The moon does not produce its own light but shines due to reflected sunlight. The document discusses the moon's phases and cycle, how its appearance changes nightly, and how the moon rotates to always keep the same face toward Earth.