Ganymede: A Relationship Between Thermal History and Crater Statistics

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Science  10 Oct 1980:
Vol. 210, Issue 4466, pp. 185-188
DOI: 10.1126/science.210.4466.185


An approach for factoring the effects of a planetary thermal history into a predicted set of crater statistics for an icy satellite is developed and forms the basis for subsequent data inversion studies. The key parameter is a thermal evolution-dependent critical time for which craters of a particular size forming earlier do not contribute to present-day statistics. An example is given for the satellite Ganymede and the effect of the thermal history is easily seen in the resulting predicted crater statistics. A preliminary comparison with the data, subject to the uncertainties in ice rheology and impact flux history, suggests a surface age of 3.8 x 109 years and a radionuclide abundance of 0.3 times the chondritic value.