Challenges for coring deep permafrost on Earth and Mars

Area of Science:

• Geosciences
• Microbiology
• Astrobiology

Background:

• Permafrost environments in the Canadian Arctic harbor unique geological and microbial characteristics.
• Accessing subpermafrost brine is crucial for understanding ancient life and planetary habitability.

Purpose of the Study:

• To collect geological and water samples from a permafrost zone and underlying brine.
• To assess microbial life within Archean rock cores.
• To evaluate challenges for future subsurface exploration missions, including those to Mars.

Main Methods:

• Scientific drilling using a triple-barrel wireline tool.
• Collection of 200 m of Archean mafic volcanic rock cores.
• Utilized hot water for drilling and stringent quality assurance/quality control (QA/QC) protocols.

Main Results:

• Recovered frozen Archean mafic volcanic rock cores from the permafrost-subpermafrost boundary.
• Detected viable anaerobic microorganisms within the cores, distinct from drilling contaminants.
• Observed borehole closure at 125 m depth due to ice formation from water vapor condensation.

Conclusions:

• The recovered cores contain indigenous anaerobic microorganisms.
• Borehole icing presents a significant challenge for accessing subpermafrost brine.
• Future Mars missions require borehole stability and heating mechanisms to prevent closure.