* No atmosphere: The Moon has no atmosphere to scatter sunlight, so there's no twilight or gradual transition between light and darkness.
* Synchronous rotation: The Moon is tidally locked to Earth. This means it rotates on its axis at the same rate it orbits Earth. As a result, the same side of the Moon always faces us.
* Lunar day and night: The "lunar day" (the time from one sunrise to the next on the Moon) is about 29.5 Earth days long. This is the same amount of time it takes the Moon to orbit the Earth. During this time, half of the Moon faces the Sun and experiences "day" while the other half is in "night".
So, while the Moon experiences periods of light and darkness, they are not the result of the Moon rotating on its axis like Earth. Instead, they are caused by its orbital position relative to the Sun.
