Tidal locking
results in the Moon rotating about its axis in about the same time it takes to orbit the Earth. Except for libration effects, this results in it keeping the same face turned towards the Earth, as seen in the figure on the upper left. (The Moon is shown in polar view, and is not drawn to scale.)
+ Upper left:
> If the Moon didn't spin at all, then it would alternately show its near and far sides to the Earth while moving around our planet in orbit.
+ Upper right:
> If rotational frequency is larger than orbital frequency, a small torque counteracting the rotation arises, eventually locking the frequencies (situation depicted in green)
+ Down left:
> A simulation shows the variability in the portion of the Moon visible from Earth due to libration over the course of an orbit. Lighting phases from the Sun are not included.
+ Down right:
> Animation of the Moon as it cycles through its phases. The apparent wobbling of the Moon is known as libration
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* Stigmatella aurantiaca
* Jim McKeeth
* Tom Ruen
* Poopooman-ger
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