According to the laws of isostasy, an evolving planetary body should acquire a spherical shape, without any significant deformation of its solidified shell. According to the laws of isostasy, the selenosphere should be attracted around with the same force by its own center of gravity. Without hesitation, with a light hand, one could say that the pear-shaped of the Moon, that is, its elongation towards the Earth, is due to the tidal forces of the Earth. The substance of the Moon, which is closer to the Earth, is attracted by the earth's forces of attraction with a greater force, and more distant - with a lesser force. Along the way, the reason for the violation of the laws of isostasy would arise. But in reality - all this is only an apparent and false idea.
In fact, two factors influenced the formation of an elongated physical surface towards the Earth: the influence of the gravitational force of the lunar core (not to mention their mutual attraction) and the influence of centrifugal force on the selenosphere, which is held around the lunar core. An inconsistency arises between the core and the selenosphere: the solidified shell, under the action of centrifugal force, is trying to break away from the orbital motion around the Earth, and the core is trying to keep it in a circular orbit. If the earth's gravity affected with the same force both on the core of the Moon and on its solidified and molten spheres, such a difference would not have arisen and the center of gravity - the core - would not have shifted towards the Earth.
This is still a theoretical proof, which will certainly be supported after a thorough study of the interior of the Moon.
The center of the Moon's gravitational forces, that is, its core, is attracted by the earth's gravity with greater force than the solidified shell. But since the lunar core is the center of the gravitational forces of the moon itself, it also keeps the entire set of lunar matter near it. The uniformity of the distribution of the forces of attraction is disturbed by the very movement of the Moon around the Earth, more precisely by centrifugal forces. These forces affect mainly the lunar crust and the layers of the inner shell. The entire aggregate of the substance of these constituent parts, moving along the orbit, is trying, as it were, to break away from the movement in a circle, and move away from the center of gravity in the opposite direction. The force of the gravitational forces of the moon prevails over centrifugal forces, holding the entire set of lunar matter and makes it move in a circular orbit together with the center of gravity. But since gravity affects more on the lunar core, and to a lesser extent on the inner shell and the selenosphere, there is a difference in gravity on the Moon itself, that is, between its constituent parts.
Different weights of the same objects in different hemispheres of the Moon
When, after landing on the surface of the Moon, a person visits the equator in the area of the visible and reverse sides, he will find a difference in weight. An astronaut on the far side of the moon will weigh less than at the same latitude of the visible side. Here it is appropriate to compare the dissimilarity of the forces of attraction on our planet at the equator and at the poles. But on Earth, in the equator around the entire globe, at all points, the forces of attraction are the same. And this is despite the fact that the center of gravity of the Earth is also shifted and does not coincide with the geographical one (shifted towards the Pacific Ocean).
The astronaut will be heavier on the visible side of the moon for two reasons. First, it will be placed closer to the center of the lunar gravity. The second - centrifugal forces will also act on it, as if pressing it to the lunar surface. He will feel the opposite on the other side.
On the opposite side, firstly, it will be farther from the center of gravity. And this already reduces its weight, even if it is very insignificant. Secondly, centrifugal forces will act to reduce its weight, which will no longer press it against the lunar surface, but, on the contrary, tear it off.
The attraction at the lunar poles is likely to be less than on the visible side in the center of the disk. It occupies an intermediate position between the attraction on the visible and reverse sides.
Of course, these are logical conclusions, but as practical measurements of the forces of gravity on the Moon will show, it will be seen. And the conclusions will be confirmed.
Apparently, the reasons for the elongated shape of the moon have already been said (and perhaps not everything). This also indicates the reason that gives rise to the pear-shaped shape of the moon. However, this still has its "but".
If the elongated shape of the moon ball could arise immediately after the capture of the Moon by the Earth, then the pear-shaped shape is a consequence of the evolutionary development of the moon after its capture or even while in the first elliptical orbit.
About the genesis of the pear-shaped, as scientists suggest, it will be possible to try to understand the issue of creating seas and oceans.
Translation from Чому Місяць набув грушовидної форми