Question #c9f34
2 Answers
International Space Station scientists (ISS) know about it.
Explanation:
In its orbit, the ISS shows bottom to us. I think, spin is set initially, when the orbit is stabilized, There are three components of axial rotation: pitch, yaw and roll. Relating to the Earth, there is no pitch for Moon. Yet, there is pitch relating to the Sun with period one lunar month.
Ref: wiki Pitch, yaw and roll in orbital mechanics.
The Moons axial rotation time is the same as that to complete one revolution around planet earth.
Explanation:
http://discovermagazine.com/2014/dec/2-ask-discover
The rotational time of the Moon around Earth ~ 27 days. These similar rates is what creates the perception that the Moons face is fixed when viewed from Earth. This is quite remarkable considering the moons orbit is not circular and furthermore its distance from Earth varies in a sinusoidal pattern.
