Subject Area
Physical Sciences, General/Other
Abstract
Permanently shadowed regions (PSRs) at the lunar south pole are a prime location for the next generation of lunar exploration due to the high likelihood of water ice and other volatiles. The cold surface temperatures observed in PSRs, as low as 20 K, indicate a favorable thermal environment for storing volatiles over geologic timescales. Mission planning and safety at the lunar south pole require reliable estimates of the thermophysical properties of lunar regolith at temperatures below ~100 K. Yet, thermophysical measurements of lunar regolith reported in the literature have primarily focused on temperatures above ~100–150 K, introducing possible errors in thermal model calculations of cold polar terrain.
This dissertation investigates the cryogenic thermal conductivity of lunar regolith and simulants through thermal modeling, remote sensing analysis, and laboratory work. A new thermal conductivity model of lunar regolith at low temperatures is presented, with implications for the surface and subsurface thermal environment of polar and near-polar surfaces and craters. The model better accommodates surface temperature trends observed by the Diviner Lunar Radiometer at warm low latitudes and colder high latitudes compared to standard models. Model results also predict warmer subsurface temperatures, larger surface temperature amplitudes in PSRs, and steeper subsurface thermal gradients, influencing the thermal stability of stored volatiles.
This work also presents measurements of lunar simulant NU-LHT-2M and Apollo 11 and 16 regolith from 15–300 K. The measurements confirm a decrease in thermal conductivity with temperature, lower than that suggested by standard thermal conductivity models.
Degree Date
Spring 5-16-2026
Document Type
Dissertation
Degree Name
Ph.D.
Department
Earth Sciences
Advisor
Matthew Siegler
Second Advisor
Heather DeShon
Third Advisor
Zhong Lu
Number of Pages
182
Format
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Recommended Citation
Martinez, Angelica, "Thermophysical Properties of Lunar Regolith under Cryogenic Conditions: Laboratory Measurements and Implications for the Lunar South Pole" (2026). Earth Sciences Theses and Dissertations. 41.
https://scholar.smu.edu/hum_sci_earthsciences_etds/41
