Accession Number:

ADA045591

Title:

A Numerical Model of the Moon's Rotation.

Descriptive Note:

Interim rept.,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF EARTH AND PLANETARY SCIENCES

Report Date:

1977-07-25

Pagination or Media Count:

31.0

Abstract:

The differential equations for the Moons rotation are derived in terms of Euler angles referenced to an inertial coordinate system. Also, the variational equations of the rotation with respect to six Euler angle initial conditions, the lunar J sub 2, the moment-of-inertia ratios Beta and Gamma, and the coefficients of the third and higher-degree gravity harmonics, are presented in detail. The equations of motion were integrated numerically within the framework of MITs Planetary Ephemeris Program, and the initial conditions were adjusted to fit the libration angles given by the numerical LLB-5 model of J.G. Williams and others at JPL. The postfit rms orientation difference, after removal of a three-axis rotation to correct for lunar orbital ephemeris differences, was about 0.03 arcsec selenocentric over a six-year span. Neglected effects and anticipated improvements in our model are also discussed.

Subject Categories:

  • Astronomy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE