Engineering topics

Kennedy, G. C.

Publications and source records attributed to Kennedy, G. C..

9 records

NASA NTRS1977

Solubility of K in Fe-S liquid, silicate-K/Fe-S/liq equilibria, and their planetary implications

Potassium has been found to have extremely limited absolute solubility in Fe-S liquid in the pressure-temperature range of 18 to 40 kbars, 1050 to 1150 C, and fO2 within the field of metallic iron. It also partitioned into a certain silicate phase highly in preference to Fe-S liquid at 30 kbar and 1100 C. The dependence of the partitioning of K between solid silicate and Fe-S liquid on fO2 and compositions of mineral solid solutions have been analyzed. These experimental data, along with those of others, limit the amount of K that could fractionate in Fe-S liquid layers or a core in the early history of the moon and, thus, act as localized heat sources in its thermal history models; the data also seem to argue against a chondritic abundance of potassium for earth. The question of fractionation of enough K-40 in an Fe-S liquid outer core of earth to provide the necesary thermal energy for the geomagnetic dynamo remains unresolved.

Gangully, J.↗

NASA NTRS1975

A lunar core and the moon's magnetic field

The suggestion that the moon's magnetic field is due to adiabatic magnetohydrodynamic convection of a molten core has been made by a number of recent authors. Considerations based on petrology, mass and rotational inertia limit the size of this hypothetical core to a few hundred kilometers at the most. A proposal has been made that this core is either molten iron or iron sulfide. The properties are known of both molten iron and iron-sulfide at lunar core pressures. No way can be found to maintain circulation in a hypothetical lunar core, as circulation is contingent upon a temperature gradient being greater than the adiabatic gradient, or an internal heat source.

Kennedy, G. C.↗

NASA NTRS1973

The core paradox.

Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

Kennedy, G. C.↗

NASA NTRS1971