Searching for life with rovers: exploration methods and science results from the 2004 field campaign of the “Life in the Atacama” project and applications to future Mars Missions

LITA develops and field tests a long-range automated rover and a science payload to search for microbial life in the Atacama. The Atacama's evolution provides a unique training ground for designing and testing exploration strategies and life detection methods for the search for life on Mars

Robotic Technologies for Surveying Habitats and Seeking Evidence of Life: Results from the 2004 Field Experiments of the "Life in the Atacama" Project

The Chilean Atacama Desert is the most arid region on Earth and in several ways analogous to Mars. Evidence suggests that the interior of the Atacama is lifeless, yet where the desert meets the Pacific coastal range dessication-tolerant microorganisms are known to exist. The gradient of biodiversity and habitats in the Atacama's subregions remain unexplored and are the focus of the Life in the Atacama project. Our field investigation attempts to bring further scientific understanding of the Atacama as a habitat for life through the creation of robotic astrobiology. This involves capabilities for autonomously traversing hundreds of kilometers while deploying sensors to survey the varying geologic and biologic properties of the environment, Fig. 1. Our goal is to make genuine discoveries about the limits of life on Earth and to generate knowledge about life in extreme environments that can be applied to future planetary missions. Through these experiments we also hope to develop and practice the methods by which a rover might best be employed to survey desert terrain in search of the habitats in which life can survive, or may have in the past

Cyanobacteria from extreme deserts to space

The development of space technology makes possible the exposure of organisms and molecules to the space environ-ment by using the ESA Biopan and Expose facilities and NASA nanosatellites; the aim is to decipher the origin, evolu-tion and distribution of life on Earth and in the Universe. The study of microbial communities thriving in lithic habitats in cold and hot deserts is gathering appreciation when dealing with the limits of life as we know it, the identification of biosignatures for searching life beyond Earth and the validation of the (litho)-Panspermia theory. Cyanobacteria of the genus Chroococcidiopsis dominate rock-dwelling communities in extreme deserts that are considered terrestrial ana-logues of Mars, like the Dry Valleys in Antarctica, the Atacama Desert in Chile or the Mojave Desert in California. The extraordinary tolerance of these cyanobacteria towards desiccation, ionizing and UV radiation makes them suitable ex-perimental strains which have been already used in astrobiological experiments and already selected for future space missions. Evidence gained so far supports the use of desert cyanobacteria to develop life support systems and in-situ resource utilization for the human space exploration and settlement on the Moon or Mars

Subsurface Microbial Habitats in an Extreme Desert Mars-Analog Environment

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 bio-availability, 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

Surface Morphologies in a Mars-Analog Ca-Sulfate Salar, High Andes, Northern Chile

Salar de Pajonales, a Ca-sulfate salt flat in the Chilean High Andes, showcases the type of polyextreme environment recognized as one of the best terrestrial analogs for early Mars because of its aridity, high solar irradiance, salinity, and oxidation. The surface of the salar represents a natural climate-transition experiment where contemporary lagoons transition into infrequently inundated areas, salt crusts, and lastly dry exposed paleoterraces. These surface features represent different evolutionary stages in the transition from previously wetter climatic conditions to much drier conditions today. These same stages closely mirror the climate transition on Mars from a wetter early Noachian to the Noachian/Hesperian. Salar de Pajonales thus provides a unique window into what the last near-surface oases for microbial life on Mars could have been like in hypersaline environments as the climate changed and water disappeared from the surface. Here we open that climatological window by evaluating the narrative recorded in the salar surface morphology and microenvironments and extrapolating to similar paleosettings on Mars. Our observations suggest a strong inter-dependence between small and large scale features that we interpret to be controlled by extrabasinal changes in environmental conditions, such as precipitation-evaporation-balance changes and thermal cycles, and most importantly, by internal processes, such as hydration/dehydration, efflorescence/deliquescence, and recrystallization brought about by physical and chemical processes related to changes in groundwater recharge and volcanic processes. Surface structures and textures record a history of hydrological changes that impact the mineralogy and volume of Ca-sulfate layers comprising most of the salar surface. Similar surface features on Mars, interpreted as products of freeze-thaw cycles, could, instead, be products of water-driven, volume changes in salt deposits. On Mars, surface manifestations of such salt-related processes would point to potential water sources. Because hygroscopic salts have been invoked as sources of localized, transient water sufficient to support terrestrial life, such structures might be good targets for biosignature exploration on Mars

Survival of the NASA Mars Odyssey isolate Acinetobacter radioresistens 50v1 on different spaceflight relevant antimicrobial surfaces

Since many years, human mankind travels to space. One of our mayor interests is the health of astronauts and the protection of the spacecraft. Apart from external influences, the microbial burden inside of the International Space Station (ISS) may be dangerous and must be limited to a minimum. To ensure the status and the protection of the crew as well as the spacecraft itself, it is necessary to determine the survival of microorganisms on different surfaces. Microorganisms are constantly changing their strategy of survival, primarily induced by extreme environmental conditions, such as space conditions, compared to their terrestrial habitats. However, the increased levels in resistance and robustness possibly play a sensitive role in evolving new virulence factors in the space environment. One of the bacteria on the NASA Mars Odyssey spacecraft, which have been isolated, is the Gram-negative, non-motile bacterium Acinetobacter radioresistens. Apart from Deinococcus radiodurans, A. radioresistens shows similar levels in radiation and oxidative stress tolerance (McCoy et al., 2012). In our work, we used the strain 50v1, isolated from the surface of the Mars Odyssey spacecraft as well as the type strain DSM6976, which was isolated on Earth from cotton and soil samples. We investigated the resistance regarding in their desiccation tolerance on metallic surfaces including materials with different antimicrobial properties. For those experiments we exposed and desiccated both strains on the different surfaces (such as copperand silver-containing materials) and determined the survival over different time points. First results show a high resistance of the spacecraft isolated strain compared to the type strain. These results give implications about the higher survivability of environmental microorganisms and highlight the essence of bioburden reduction and improve sterilization approaches/techniques for upcoming space exploration missions towards the search for life outside Earth

Biosignature Preservation and Detection in Mars Analog Environments : May 16–18, 2016, Lake Tahoe, Nevada

Our objective is to focus strategies to detect a range of possible biosignatures on Mars in different categories of geologic settings by assessing the attributes and preservation potential of various biosignatures in different Mars-analog habitable environments on Earth. We are seeking a better understanding of three broad classes of ancient environments known to exist in the martian geologic record: 1.Lacustrine and deltaic sediments, 2.Near-surface chemical sediments (including hydrothermal and pedogenic), or 3. Deep crustal rocks (including hydrothermally altered).Universities Space Research AssociationNational Aeronautics and Space AdministrationUniversities Space Research AssociationNational Aeronautics and Space AdministrationLunar and Planetary InstituteConveners: Lindsay Hays, Jet Propulsion Laboratory, David Beaty, Jet Propulsion Laboratory, Mary Voytek, NASA Headquarters, Michael Meyer, NASA Headquarter

Analogue sites for Mars missions : MSL and beyond : March 5-6, 2011, The Woodlands, Texas

The goal of the workshop is to develop an inventory of analogue sites that have value to NASA's Mars Science Laboratory (MSL), the Mars 2018 missions, and Mars analogue missions by the Canadian Space Agency and other space agencies. There will be a strong focus on outstanding science questions and Mars habitability.National Aeronautics and Space Administration, Lunar and Planetary Instituteconveners, Mary Voytek ... [and others]PARTIAL CONTENTS: Rover Science Operations: Lessons from Rocky 7 and FIDO Field Experiments and Mars Exploration Rover Flight Operations / R.E. Arvidson--Small, Fresh Craters at the Nevada Test Site / L.E. Kirkland and K.C. Herr--Lava Tubes as Analog Repositories for Life, Geochemistry, and Climate Records on Mars / P. Boston, J.G. Blank, D.E. Northup, and M. Deans