Topography formation driven by sublimation of pure species on icy airless worlds

• Published in: Icarus (New York, N.Y. 1962) Vol. 415; p. 116043
• Main Authors: Macias Canizares, Antonio, Berisford, Daniel F., Goldstein, David, Varghese, Philip, Trafton, Laurence, Steckloff, Jordan, Hand, Kevin P.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.06.2024
• Subjects: Icy airless worlds; Molecular transport; Sublimation Monte Carlo; Surface morphology; Icy airless worlds; Molecular transport; Surface morphology; Sublimation Monte Carlo
• ISSN: 0019-1035
• DOI: 10.1016/j.icarus.2024.116043

Sublimation can drive morphologic changes on the surfaces of icy, airless worlds; the magnitude of these changes depends sensitively on their surface shape, subsurface geology, and volatility of the ice species present. To predict the steady-state and stability of the surface, we examine the molecular transport conditions and their constraints for several pure species sublimating from irregular surfaces in a free-molecular regime subject to variations in thermal conditions at or near the surface. We find that the temperature difference, ΔT∗ between the high and low points on the surface required for morphological instability changes of a given surface geometry increases as the volatility of the ice species increases. From Figure 4, for k=1 and Ts=150K, ΔT∗ is about 3K for H2O and 5K for CO2. Furthermore, we developed an analytical relationship between the saturation vapor pressure of a pure species, its surface geometry and temperature profile, and the required molecular transport conditions. •We discuss sublimation of pure species in a free molecular regime.•This manuscript details the molecular transport conditions required to destabilize icy surfaces.•The stable morphology of isothermal surfaces is planar regardless of geometry and composition.