Experiments On Sublimating Carbon Dioxide Ice And Implications For Contemporary Surface Processes On Mars.

Area of Science:

• Planetary Science
• Geomorphology
• Mars Surface Processes

Background:

• Carbon dioxide (CO2) is the primary atmospheric gas on Mars and drives surface changes.
• CO2 ice sublimation is hypothesized to form various Martian surface features, but lacks experimental validation.
• Previous research has proposed CO2 ice sublimation for Martian dune features, requiring further investigation.

Purpose of the Study:

• To experimentally investigate CO2 ice sublimation's role in creating Martian dune morphology.
• To test if sublimating CO2 ice interacting with regolith can form features similar to those observed on Mars.
• To propose a new hypothesis for detached pit formation on Martian dunes.

Main Methods:

• Laboratory experiments simulating CO2 ice block interaction with porous regolith.
• Morphological analysis of features generated by CO2 sublimation.
• Geomorphic comparison of experimental results with Martian dune features.
• Scaling arguments to relate laboratory findings to Martian conditions.

Main Results:

• CO2 sublimation was found to mobilize regolith grains, forming pits and furrows.
• Detached pits were observed at the termini of linear gullies on Martian dunes.
• Erosion patterns beneath sublimating CO2 ice blocks mimicked Martian furrow patterns.

Conclusions:

• CO2 ice sublimation is a viable mechanism for mobilizing Martian regolith and forming surface features.
• The impact of granular jets from sublimating CO2 is a plausible cause for detached pits on Martian dunes.
• Laboratory findings support CO2 sublimation as a key process in contemporary Martian surface evolution.