22-EPN3-061: CO2 Ice Crystals Formation Under Conditions in the Martian Polar Regions
October 7, 2023

22-EPN3-061: CO2 Ice Crystals Formation Under Conditions in the Martian Polar Regions: Influence of Substrate Properties and Temperature Gradient

Visit by Ganna Portyankina, DLR (Germany), to TA2.4 Planetary Environment Facilities (PEF), AU (Denmark)
Dates of visit: 30 April – 01 October 2023 (two visits)

Report summary: The main goal of most recent tests conducted at the Planetary Environment Facilities at Aarhus University was to condense CO2 from the chamber’s atmosphere under Martian conditions onto a specially designed set of different surface materials (martian regolith simulant, glass beads of various sizes, dust). We investigated ranges of temperatures and pressures and observed the texture of the created CO2 ice. Our goal was to determine if CO2 deposits over regolith/glass beads/dust differently compared to brushed aluminium. We have observed that various properties of substrate did not considerably alter the deposition morphologies of CO2 observed in our previous work. Most importantly, we find that under conditions usual for Martian polar areas in fall and winter, CO2 ice always deposits as a translucent slab.  Under deviating conditions, i.e. colder temperatures and lower pressures, CO2crystals assume different shapes including opaque slab and highly porous multi-crystalline. Such CO2crystalline morphologies require further investigations, because of their relevance to icy satellite surfaces as well as CO2 cloud formation.

Read the full scientific report, with kind permission from Ganna Portyankina.