scholarly journals On the Deviation of the Lunar Center of Mass to the East: Two Possible Mechanisms Based on Evolution of the Orbit and Rounding Off the Shape of the Moon

Lunar Science ◽  
2019 ◽  
Author(s):  
Boris P. Kondratyev
Keyword(s):  
2011 ◽  
Vol 1 (4) ◽  
pp. 348-354 ◽  
Author(s):  
H. İz ◽  
X. Ding ◽  
C. Dai ◽  
C. Shum

Polyaxial Figures of the MoonThis study investigates various models to represent the gross geometric shape of the Moon. Asymmetric polyaxial geometric models-namely three-, four- and six-axial lunar figure - are compared and contrasted with the axially symmetric three-axis ellipsoidal model derived from Chang'e 1 and SELENE laser altimetry data. All solutions confirm a hydrostatically stable lunar shape shifted with respect to the lunar center of mass by topography. Model solutions with increasing complexity offer additional information about the regional properties of the lunar topography. Solution statistics suggest that axially symmetric lunar figures and their center of figure parameters can be replaced by an equivalent asymmetric lunar shape centered at the center of mass of the Moon. Thus, using only three shape parameters, one can derive an "egg" shape that better accommodates the true geometry of the Moon.


1978 ◽  
Vol 46 (7) ◽  
pp. 762-762
Author(s):  
Allan Walstad
Keyword(s):  

1986 ◽  
Vol 114 ◽  
pp. 141-144
Author(s):  
M. Moons

Very accurate theories of the libration of the Moon have been recently built by Migus (1980), Eckhardt (1981, 1982) and Moons (1982, 1984). All of them take into account the perturbation due to the Earth and the Sun on the motion of a rigid Moon about its center of mass. Additional perturbations (influence of the planets, shape of the Earth, elasticity of the Moon, …) are also often included.We present here the perturbations due to the shape of the Earth and the motion of the ecliptic plane on our theory which already contains planetary perturbations. This theory is completely analytical with respect to the harmonic coefficients of the lunar gravity field which is expanded in spherical harmonics up to the fourth order. The ELP 2000 solution (Chapront and Chapront-Touzé, 1983) supplies us with the motion of the center of mass of the Moon.


1981 ◽  
Vol 63 ◽  
pp. 281-286
Author(s):  
V. S. Kislyuk

The selection of selenodetic reference coordinate system is an important problem in astronomy and selenodesy. For the purposes of reduction of observations, planning and executing space missions to the Moon, it is necessary, in any case, to know the orientation of the adopted selenodetic reference system in respect to the inertial coordinate system.Let us introduce the following coordinate systems: C(ξc, ηc, ζc), the Cassini system which is defined by the Cassini laws of the Moon rotation;D(ξd, ηd, ζd), the dynamical coordinate system, whose axes coincide with the principal axes of inertia of the Moon;Q(ξq, ηq, ζq), the quasi-dynamical coordinate system connected with the mean direction to the Earth, which is shifted by 254" West and 75" North from the longest axis of the dynamical system (Williams et al., 1973);S(ξs, ηs, ζs), the selenodetic coordinate system, which is practically realized by the positions of the points on the Moon surface given in Catalogues;I(X,Y,Z), the space-fixed (inertial) coordinate system. All the systems are selenocentric with the exception of S(ξs, ηs, ζs On the whole, the origin of this system does not coincide with the center of mass of the Moon.


2012 ◽  
Vol 2 (2) ◽  
pp. 107-112
Author(s):  
H. Iz ◽  
C. Shum ◽  
C. Dai

Polyaxial figures of the Moon from the lunar reconnaissance orbiter laser altimetry and multi-mission synthesis of the lunar shapeLast decade witnessed a plethora of missions to the Moon by China (Chang'E-1 and Chang-E-2), Japan (SELenological and ENgineering Explorer, SELENE), India (Chandrayaan-1) and USA (Lunar Reconnaissance Orbiter), all carried out laser altimetry measurements. This study is a follow up to a series of earlier investigations that produced a number of new models to represent the gross geometric shape of the Moon using Unified Lunar Control 2005, Chang'E-1, and SELENE laser altimetry data using the Lunar Reconnaissance Orbiter laser altimetry measurements. The symmetric and asymmetric polyaxial geometric models derived from Lunar Reconnaissance Orbiter laser altimetry data, namely, three, four and six-axial lunar figure parameters, are compared and contrasted with the corresponding model parameters estimated from the Chang'E-1 and SELENE laser altimetry. All solutions produced geometric shape, orientation parameters, and the parameters of the geometric center of lunar figure with respect to the center of mass of the Moon showing remarkable agreement with each other within 100 m. A combined solution by the fusion of uniformly sampled laser altimetry data from all three missions produced the best estimates for the lunar shape, orientation, and lunar center of figure parameters, and their realistic error estimates.


Sign in / Sign up

Export Citation Format

Share Document