@article{468d794189b7457e8c5fd8f334bfa2bf,
title = "Subsurface microbial habitats in an extreme desert Mars-analog environment",
abstract = "Sediments in the hyper-arid core of the Atacama Desert are a terrestrial analog to Mars regolith. Understanding the distribution and drivers of microbial life in the sediment may give critical clues on how to search for biosignatures on Mars. Here, we identify the spatial distribution of highly specialized bacterial communities in previously unexplored depth horizons of subsurface sediments to a depth of 800 mm. We deployed an autonomous rover in a mission-relevant Martian drilling scenario with manual sample validation. Subsurface communities were delineated by depth related to sediment moisture. Geochemical analysis indicated soluble salts and minerology that influenced water bioavailability, particularly in deeper sediments. Colonization was also patchy and uncolonized sediment was associated with indicators of extreme osmotic challenge. The study identifies linkage between biocomplexity, moisture and geochemistry in Mars-like sediments at the limit of habitability and demonstrates feasibility of the rover-mounted drill for future Mars sample recovery.",
keywords = "Atacama, Desert soil, Mars, Moisture stress, Soil bacteria",
author = "Warren-Rhodes, {Kimberley A.} and Lee, {Kevin C.} and Archer, {Stephen D.J.} and Nathalie Cabrol and Linda Ng-Boyle and David Wettergreen and Kris Zacny and Pointing, {Stephen B.}",
note = "Funding Information: The work was completed with funding from NASA Astrobiology Science and Technology for Exploring Planets (ASTEP) Program Grant NNX11AJ87G and a Yale-NUS College Start-Up Grant. NASA Life in the Atacama Project team members that contributed to the success of this research: Guillermo Chong (Universidad Cat{\'o}lica del Norte), Cecilia Demargasso (Universidad Cat{\'o}lica del Norte), Greydon Foil (Carnegie-Mellon University), Christopher Gayle Tate (University of Tenessee), Trent Hare (United States Geological Survey), Donnabella C. Lacap-Bugler (Auckland University of Technology), Jeff Moersch (University of Tenessee), Ken Tanaka (United States Geological Survey), Cinthya Tebes (Universidad Cat{\'o}lica del Norte), Srinivasan Vijayarangan (Honeybee Robotics and Spacecraft Mechanisms Corp.), Michael Wagner (Carnegie-Mellon University), Alian Wang (Washington University), Jie Wei (Washington University). Publisher Copyright: Copyright {\textcopyright} 2019 Warren-Rhodes, Lee, Archer, Cabrol, Ng-Boyle, Wettergreen, Zacny, Pointing and the NASA Life in the Atacama Project Team.",
year = "2019",
doi = "10.3389/fmicb.2019.00069",
language = "English (US)",
volume = "10",
journal = "Frontiers in Microbiology",
issn = "1664-302X",
publisher = "Frontiers Media S. A.",
number = "FEB",
}