Online Astronomy eText: Natural Satellites (Moons) / The Sky
The Rotation of the Moon Link for sharing this page on Facebook
      This page will discuss various aspects of the Moon's rotation, among them the reason that the Moon always keeps one face to the Earth (synchronous rotation), and small variations in the portion we can see due to the tilt of its orbit relative to our orbit and changes in its orbital speed as it moves toward or away from us. I will also post an illustration based on old maps of the Moon that showed (by use of overlapping regions) what portion of the Moon is always visible, and what portions are visible only when it was tilted toward or away from us in a particular way. For now, to see how the appearance of the Moon changes, refer to Animation of the Moon's Phases.

(refer to Rotation Period and Day Length for a detailed discussion of how rotation periods are related to day length)