Temperature dependence of specific heat capacity and its effect on asteroid thermal models

CONCLUSIONS

Specific heat capacities of minerals and, probably, asteroidal bulk compositions show considerable variations with temperature. Variations in specific heat capacity produce different peak tempera­ tures and closure ages. This can result in incorrect inferences about the nature of meteorite parent bodies. For example, in an ordinary chondrite parent body, incorrect modeling of peak temperatures and closure ages can result in inaccuracies in the calculated radius of the parent body and in the computed volume proportions of various petrologic types. The estimated accretion time in a model which uses short-lived radionuclides as a heat source is also dependent on specific heat capacity. Because the temperature dependence of specific heat capacity has a considerable effect on thermal models, a greater database of experimental data on specific heat capacity of various mineral compositions and their dependence on temperature is needed.

Acknowledgements- This work was supported by NASA Origins of Solar Systems grant NAG 54387. We thank Christian Halloy of the UT-ORNL Joint Institute of Computational Science (JICS) for unlimited use of computer facilities. A. J. Baker helped set up this problem in its finite element formulation. The paper benefited from detailed reviews by Dr. Paul Benoit and an anonymous reviewer.

Editorial handling: R. P. Binzel