Ultrasonic velocity measurements of simulated lunar regolith with variable ice content: a laboratory and modeling investigation with implications for geophysical lunar resource exploration

Private companies and governments alike have expressed interest in characterizing the location and abundance of water ice on the Moon. Water not only provides valuable insight into the Moon’s history but could also be processed into human consumables or rocket propellant for future missions. To date, remote sensing measurements have established the presence of water ice within some craters near the lunar poles, but little is known about the distribution and concentration of ice throughout the lunar soil, or regolith. An upcoming NASA mission plans to directly sample the upper meter of potentially ice-bearing regolith in the Moon’s south pole region which will provide significant constraint on ice properties. However, this mission does little to inform ice concentration and distribution over the large spatial scales that would be required to identify an economically viable subsurface ice deposit. Geophysical techniques such as seismic methods are routinely used on Earth to extrapolate information from samples over tens of meters to thousands of kilometers and are suitable to do the same for extraterrestrial bodies. This study aims to advance our understanding of how seismic methods may be used to explore for subsurface water ice deposits on the Moon. I performed ultrasonic velocity measurements of simulated lunar regolith at low temperature and low confining pressure with varying concentration and texture of water ice and developed a predictive rock physics model calibrated with these measurements. To build confidence in this approach, I show that seismic velocity predicted by my rock physics model agrees with near-surface seismic data collected by the Apollo 14 and 16 missions. My laboratory measurements and model show that seismic velocity is sensitive to ice concentration, however this sensitivity varies significantly with ice texture. These results indicate that seismic methods would be an impactful addition to a comprehensive lunar ice exploration mission.

Name thesis:degree_name

Doctor of Philosophy (Ph.D.)

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2024

Author dc:creator

• Amos, Christopher Chance

Advisor dc:contributor.advisor

• Cannon, Kevin M.

Committee members dc:contributor.committeemember

• Prasad, Manika
• Dreyer, Christopher B.
• Putzig, Nathaniel E.
• Sava, Paul C.

• lunar ice
• moon
• rock physics
• seismic
• space resources
• ultrasonic velocity

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Dc Identifier Other

T 9740

OAI identifier oai:identifier

oai:repository.mines.edu:11124/179288