A "cryptic" microbial mat: a new model ecosystem for extant life on Mars

Area of Science:

• Astrobiology
• Microbiology
• Environmental Science

Background:

• Martian surface conditions (lack of water, extreme temperatures, UV radiation, oxidants) pose significant challenges to life.
• Viking missions found no detectable near-surface organic carbon, suggesting a need for alternative carbon sources for potential Martian life.

Purpose of the Study:

• To investigate terrestrial microbial communities as a model for potential extant Martian life.
• To assess the ability of near-surface microbial communities to fix carbon under simulated Martian-relevant conditions.

Main Methods:

• Studied two terrestrial photosynthetic microbial communities: one in Laguna Ojo de Liebre, Mexico, and another in Yellowstone National Park, USA.
• Analyzed carbon fixation capabilities under various conditions, including elevated inorganic carbon levels.

Main Results:

• Identified terrestrial sand and gravel microbial communities capable of photosynthesis and carbon fixation.
• These communities demonstrate potential survival strategies against UV radiation and lack of fixed carbon.

Conclusions:

• Terrestrial near-surface microbial communities, particularly those under sand or gravel, can serve as valuable model ecosystems for studying potential extant Martian life.
• Further research on these models can inform our understanding of life's adaptability in extreme extraterrestrial environments.