Use of an Analytical Theory for the Physical Libration of the Moon to Detect Free Nutation of the Lunar Core

2018 ◽  
Vol 62 (12) ◽  
pp. 1021-1025 ◽  
Author(s):  
N. K. Petrova ◽  
Yu. A. Nefedyev ◽  
A. A. Zagidullin ◽  
A. O. Andreev
Keyword(s):  
Analytical Theory ◽  
The Moon ◽  
Physical Libration ◽  
Free Nutation ◽  
Lunar Core

scholarly journals Application of the Spectral Analysis for Modeling the Rotations of the Moon

2010 ◽  
Vol 45 (4) ◽  
pp. 153-162 ◽  
Author(s):  
V. Pashkevich ◽  
G. Eroshkin
Keyword(s):  
Spectral Analysis ◽  
Numerical Solution ◽  
Rotational Motion ◽  
Initial Conditions ◽  
Analytical Theory ◽  
Time Interval ◽  
The Moon ◽  
Physical Libration ◽  
Newtonian Case ◽  
Rotational Motions

Application of the Spectral Analysis for Modeling the Rotations of the Moon The main purposes of this research are the development of the optimal spectral analysis schemes for the investigation of the rotational motion of the Moon and then the comparison between the result of the optimal spectral analysis of the rotational motions of the Earth and the Moon. Dynamics of the rotational motion of the Moon is studied numerically by using Rodrigues-Hamilton parameters over 418.9 year time interval. The results of the numerical solution of the problem are compared with the composite semi-analytical theory of the Moon rotation (SMR) represented by Cassini relations and the semi-analytical solutions of the lunar physical libration problem (Eckhardt, 1981), (Moons, 1982), (Moons, 1984), (Pešek, 1982). The initial conditions of the numerical integration are taken from SMR. The investigation of the discrepancies is carried out by the optimal spectral analysis methods for the Newtonian case. All the periodic terms representing the behavior of the residuals are interpreted as corrections to SMR semi-analytical theory. As a result, the Moon Rotation Series (MRS2010) is constructed, which is dynamically adequate to the DE200/LE200 ephemeris over 418.9 year time interval. A numerical solution for the Moon rotation is obtained anew with the new initial conditions calculated by means of MRS2010. The discrepancies between the new numerical solution and MRS2010 do not surpass 20 mas over 418.9 year time interval. The result of the comparison demonstrates that MRS2010 series represent more accurately the Moon rotation than SMR series.

Magnetism of the Moon - a lunar core dynamo or impact magnetization?

1993 ◽  
Vol 14 (1) ◽  
pp. 89-118 ◽  
Author(s):  
D. W. Collinson
Keyword(s):  
The Moon ◽  
Lunar Core

Physical Libration of the Moon: An Extended Problem

2020 ◽  
Vol 64 (12) ◽  
pp. 1093-1106
Author(s):  
A. A. Zagidullin ◽  
V. S. Usanin ◽  
N. K. Petrova ◽  
Yu. A. Nefedyev ◽  
A. O. Andreev ◽  
...  
Keyword(s):  
The Moon ◽  
Physical Libration ◽  
Extended Problem

scholarly journals Analytical Theories of the Motion of the Moon

1981 ◽  
Vol 63 ◽  
pp. 227-232
Author(s):  
Jacques Henrard
Keyword(s):  
Numerical Integration ◽  
Analytical Theory ◽  
The Moon

AbstractAlmost every aspect of the analytical theory of the motion of the Moon has been reinvestigated lately. This paper is a review of these investigations.The improvement upon the I.L.E. (the best known earlier theory based upon the work of Brown) is spectacular, but it is still too early to assess the exact value of these theories with respect to numerical integration.

Convection in the Moon and the existence of a lunar core

1967 ◽  
Vol 296 (1446) ◽  
pp. 270-284 ◽  
Keyword(s):  
Hydrostatic Equilibrium ◽  
The Moon ◽  
Important Clue ◽  
Satisfactory Theory ◽  
Lunar Core

The marked departure of the Moon from hydrostatic equilibrium is an important clue to its physical evolution. The ellipticity of the earthward bulge, determined statistically from the geometrical librations, is over twice that determined dynamically from Cassini’s laws. The inference is drawn that the internal density varies with angle. This may arise through convection or because the Moon has a finite strength which enables original density anomalies to be retained. The latter explanation is untenable if creep rates in the interior exceed 10 –20 s –1 . The hypothesis of flow suggests a search for evidence of small movements in the surface. A satisfactory theory must explain why the mechanical ellipticity is neither ¼ nor 1.

The free librations of a dissipative Moon

1981 ◽  
Vol 303 (1477) ◽  
pp. 327-338 ◽  
Keyword(s):  
Rotation Axis ◽  
Laser Ranging ◽  
The Moon ◽  
Lunar Laser Ranging ◽  
Fluid Friction ◽  
Tidal Friction ◽  
Fluid Turbulence ◽  
Lunar Laser ◽  
Solid Friction ◽  
Lunar Core

Dissipation in the Moon produces a small offset, ca. 0.23", of the Moon's rotation axis from the plane defined by the ecliptic and lunar orbit normals. Both solid body tidal friction and viscous fluid friction at a core—mantle interface are plausible mechanisms. In this paper, I discuss the merits of each and find that solid friction requires a low lunar tidal Q , ca . 28, while turbulent fluid friction requires a core of radius 330 km to cause the signature observed by lunar laser ranging. Large ( ca . 0.4—8.0") free librations of the lunar figure have also been detected by laser ranging. Both a very recent impact on the Moon and fluid turbulence in the lunar core are plausible mechanisms for generating these free librations.

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