ИСТИНА

From observations it is known that the ce n- ter of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not directly on the center of the Ear th and deviates to the South - East. This paper investigates and e x- plains the effect of steady - deviation of principal axis of inertia ellipsoid of the Moon to the South from the direction to the Earth. To this end, we studied the physical libration of the mo on in latitude. We consider a system of five linear diffe r- e n tial equations obtained by the new vector method and taking into account the perturb a- tions from the Earth [ 1 ,2 ] . Obtained the chara c- te r i s tic equation for this system and found all five frequencies. Special attention is paid on the fifth (zero) frequency for which the solution of the equations of libration in latitude is statio n- ary and represents a pr eviously unknown add i- tional motion to the axis of rotation of the Moon through the cone with small cone angle.