Antarctic environments as models of planetary habitats: University Valley as a model for modern Mars and Lake Untersee as a model for Enceladus and ancient Mars

Abstract

The worlds in our Solar System of interest for the search for a second genesis of life are Mars, and oceans beneath the icy surfaces of the moons of the outer Solar System, in particular Enceladus. All of these worlds are extremely cold compared to the Earth. Thus, environments in the Antarctic represent useful analogues for studies of habitability in these other worlds, and research sites to develop strategies to search for life. Here we discuss two key analogue environments: permafrost soils in University Valley, a high elevation dry valley, as an analogue for modern Mars, and the perennially ice-covered Lake Untersee as an analogue for crater lakes on early Mars and subsurface oceans under ice. For Mars, the Antarctic analogues appear to discourage hope for life present on the surface today while also indicating that ice-covered lakes could have been a habitat for life over a more extensive period of Martian history than previously thought. For the ice-covered ocean worlds, the Antarctic analogues support the hypothesis that these habitats are suitable for microbial life. The study of Antarctic analogues provides a focusing of scientific approaches and a way to test ideas in advance of lengthy and expensive planetary missions.

Keywords:

• Antarctica
• Mars
• Enceladus
• search for life

Acknowledgement

The authors are grateful for support from NASA, the NSF US Antarctic Program, the Russian Antarctic Expedition (AARI/RAE), the Tawani Foundation, the Trottier Family Foundation and the Antarctic Logistics Company, Inc (ALCI).

Notes

¹ Borucki, “Kepler Planet-detection.”

² Borucki, “Kepler-62.”

³ Grotzinger, “A Habitable Fluvio-lacustrine Environment.”

⁴ Murchie, “A Synthesis of Martian Aqueous Mineralogy”; Bibring, “Global Mineralogical and Aqueous Mars History”; Mustard, “Hydrated Silicate Minerals on Mars”; and Ehlmann, “Mineralogy of the Martian Surface.”

⁵ Ibid.; Ehlmann, “Subsurface Water and Clay Mineral Formation”; and Wray, “Diverse Aqueous Environments on Ancient Mars.”

⁶ Davis, “Origins of Life.”

⁷ Davies, “Life’s Rapid Appearance.”

⁸ McKay, “History of Water on Mars.”

⁹ Grotzinger, “A Habitable Fluvio-lacustrine Environment.”

¹⁰ McKay, “History of Water on Mars”; and Davila, “The Last Possible Outposts for Life on Mars.”

¹¹ Noy-Meir, “Desert Ecosystems”; and Pointing, “ Microbial Colonization.”

¹² Davila, “The Last Possible Outposts for Life on Mars”; Battistuzzi, “A genomic Timescale”; and Battistuzzi, “A Major Clade of Prokaryotes.”

¹³ Davila, “The Last Possible Outposts for Life on Mars.”

¹⁴ McKay, “The Icebreaker Life Mission to Mars.”

¹⁵ Laskar,- “Orbital Forcing.”

¹⁶ Ibid.; and Costard, “Formation of Recent Martian Debris Flows.”

¹⁷ Smith, “H2O at the Phoenix Landing Site.”

¹⁸ Byrne, “Distribution of Mid-latitude Ground Ice.”

¹⁹ Mykytczuk, “Bacterial Growth at –15 °C”; Rivkina, “Metabolic Activity of Permafrost Bacteria”; and Gilichinsky, “Microbial Populations in Antarctic Permafrost.”

²⁰ Porco, “Cassini Observes.”

²¹ Postberg, “Sodium Salts.”

²² Postberg, “Refractory Organic Compounds”; and Waite, “Liquid Water on Enceladus.”

²³ Ibid.

²⁴ Waite, “Cassini Finds Molecular Hydrogen.”

²⁵ McKay, “The Possible Origin.”

²⁶ McKay, “Follow the Plume.”

²⁷ Levy, “Thermal Contraction”; Marchant, “Antarctic Dry Valleys”; and Heldmann, “The High Elevation Dry Valleys.”

²⁸ Clow, “ Climatological Observations”; Doran, “Valley Floor Climate Observations”; Doran, “Hydrologic Response”; and McKay, “Testing.”

²⁹ Lacelle, “Solar Radiation.”

³⁰ Marinova, “Distribution of Depth”; and McKay, “Snow Recurrence.”

³¹ Ibid.; Lacelle, “Solar Radiation”; and Lacelle, “ Excess Ground Ice.”

³² Goordial, “Nearing the Cold-arid Limits.”

³³ Zent, “A Historical Search.”

³⁴ Hermichen, “Lake Untersee.”

³⁵ Andersen, “Climate Conditions.”

³⁶ Wand, “Biogeochemistry.”

³⁷ Andersen, “Discovery of Large Conical Stromatolites.”

³⁸ Ibid.

³⁹ Steel, “Modeling Circulation.”

⁴⁰ Hsu, “Ongoing Hydrothermal”; and Sekine, “High-temperature.”

⁴¹ Steel, “Abiotic and Biotic.”

⁴² Klein, “Biological Experiments.”

⁴³ Boughner, “Microbial Ecology.”

⁴⁴ Orgel, “Prebiotic Chemistry.”

⁴⁵ McKay, “The Search for a Second Genesis.”