* The Moon rotates: It takes the Moon about 27.3 days to complete one rotation on its axis. It also takes about the same amount of time to orbit the Earth. This synchronous rotation means that the same side of the Moon always faces Earth.
* Sunlight reaches all sides: Because the Moon rotates, all of its surface is exposed to sunlight at some point during its orbit. The "dark side" of the Moon is simply the side facing away from Earth at any given moment.
So, where is it dark on the Moon?
* The side facing away from the Sun: Just like on Earth, the part of the Moon not facing the Sun is in darkness. This side changes constantly as the Moon orbits the Earth.
* Inside craters: Some craters on the Moon have permanently shadowed regions where sunlight never reaches. These areas are extremely cold.
Key takeaway: The Moon doesn't have a permanent "dark side." Every part of the Moon experiences both day and night.
