Smoothed particle hydrodynamics modeling of volatile emissions: Drill-induced releases in the Martian subsurface

Abstract

This study presents a novel theoretical model based on Smoothed Particle Hydrodynamics (SPH) to simulate volatile emissions triggered by drilling operations on Mars, specifically focusing on the ESA Rosalind Franklin rover’s subsurface exploration of Oxia Planum. The model captures early time interactions between vapor, water ice, dust, and atmospheric carbon dioxide, accounting for thermal and dynamical interactions, and phase transitions dynamics during drilling. The three dimensional borehole and drill geometry are explicitly modeled, along with realistic temperature profiles derived from Martian surface and subsurface conditions. Vapor is assumed to originate from sublimation of water ice due to drill-induced heating. The simulations investigate how different initial volatile compositions, icy grain sizes, and borehole depths influence material redistribution. Results show that the distribution of ice is mainly governed by sublimation and recondensation cycles. When smaller icy grains are considered, water vapor tends to condense efficiently on colder surfaces, forming thin ice layers on the drill rod. Larger icy grains, instead, form more slowly and experience weaker atmospheric drag, occasionally enabling a small fraction to escape the borehole. Moreover, the presence of carbon dioxide alters the vertical motion of dust, constraining it to remain stuck at the bottom of the borehole. The presented model provides a tool to constrain the early-time dynamics of drilling-induced volatile release on Mars and offers a modular framework adaptable to other planetary environments, like the Moon.