Three-Dimensional Geologic Modelling Beyond Earth: Challenges and Perspectives

Three-dimensional geologic modeling is a well-established technique developed in the last twenty years and currently applied in terrestrial mining, environmental management, and hydrogeology [1,2]. It also represents a critical frontier for planetary exploration, from fundamental scientific research and the search for subsurface life to operational applications such as mission planning or In-Situ Resource Utilization (ISRU).  As missions increasingly target the shallow subsurface of the Moon and Mars, reconstructing subsurface architectures from available observations has become essential.

The primary challenge in planetary subsurface modeling lies in the extreme scarcity of direct subsurface data compared to the abundance of orbital remote sensing observations. Consequently, geologic mapping becomes the foundational prerequisite, providing the primary spatial and qualitative data needed to interpolate and propagate geologic contacts through three-dimensional volumes.

This work explores modeling approaches through experiments designed to test their applicability to planetary science. These include a volumetric model of Tempe Terra on Mars based solely on geological map information, and a benchmark study of a terrestrial impact crater using sparse drilling data to define the contact between bedrock and impact ejecta. Key findings relate to uncertainty evaluation and the importance of defining modeling objectives, which directly affect model complexity.

This research emphasizes avoiding "black box" solutions by adopting Free and Open Source Software workflows to ensure interoperability, traceability, and reproducibility—critical requirements in the demanding operational context of space exploration. Current results and modeling environments are promising for extraterrestrial applications. By integrating scientific reasoning with advanced interpolation algorithms, three-dimensional geologic modeling can generate robust predictive models essential for planning future robotic and human exploration missions.

References: [1] P. Calcagno et al. en. In: Physics of the Earth and Planetary Interiors 171.1-4 (Dec. 2008), pp. 147–157. [2] F. Wellmann and G. Caumon. In: Advances in Geophysics. Vol. 59. Elsevier, 2018, pp. 1–121.

Acknowledgements: This study is carried out within the Space It Up project funded by the Italian Space Agency, ASI, and the Ministry of University and Research, MUR, under contract n. 2024-5-E.0 - CUP n. I53D24000060005.