Contribution of tidal dissipation to lunar thermal history
Abstract
The possible contributions of tidal heating to lunar thermal history are investigated. Analytic determinations of tidal dissipation in a homogeneous, incompressible Moon and in a twolayer Moon with a soft core and rigid mantle are given as a function of position in the Moon and as a function of EarthMoon separation. The most recent information on the historical values of the lunar obliquity is employed, and we present results for the constant values of orbital eccentricity of e = 0.0 and e = 0.055. For a simplified orbital evolution and a dissipation factor Q = 100, the total increase in the mean lunar temperature for the homogeneous case does not exceed several tens of degrees. For the twolayer models the local dissipation may be enhanced over that of the homogeneous Moon by a factor of 5 for a core radius of 0.5 lunar radii and by a factor of 100 for a core radius of 0.95 lunar radii. The corresponding factors for the total dissipation are 3 and 15 for the two values of core radii, respectively. We conclude that tidal contributions to lunar thermal history are probably not important. But under special circumstances the enhanced dissipation in a twolayer Moon could have led to a spectacular thermal event.
 Publication:

Icarus
 Pub Date:
 November 1978
 DOI:
 10.1016/00191035(78)901094
 Bibcode:
 1978Icar...36..245P
 Keywords:

 EarthMoon System;
 Energy Dissipation;
 Lunar Evolution;
 Lunar Temperature;
 Lunar Tides;
 Compressibility;
 Eccentric Orbits;
 Lunar Core;
 Lunar Crust;
 Lunar Mantle;
 Lunar Orbits;
 Lunar Rotation;
 Orbital Resonances (Celestial Mechanics);
 TIDES;
 HEAT SOURCES;
 MOON;
 THERMAL HISTORY;
 ORBITS;
 EVOLUTION;
 RADIUS;
 ENERGY;
 MODELS;
 INCOMPRESSIBILITY;
 THERMAL PROPERTIES;
 CORE;
 MANTLE;
 TEMPERATURES;
 EARTH;
 DISTANCE;
 ECCENTRICITY;
 LIBRATIONS