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Spry JA, Siegel B, Bakermans C, Beaty DW, Bell MS, Benardini JN, Bonaccorsi R, Castro-Wallace SL, Coil DA, Coustenis A, Doran PT, Fenton L, Fidler DP, Glass B, Hoffman SJ, Karouia F, Levine JS, Lupisella ML, Martin-Torres J, Mogul R, Olsson-Francis K, Ortega-Ugalde S, Patel MR, Pearce DA, Race MS, Regberg AB, Rettberg P, Rummel JD, Sato KY, Schuerger AC, Sefton-Nash E, Sharkey M, Singh NK, Sinibaldi S, Stabekis P, Stoker CR, Venkateswaran KJ, Zimmerman RR, Zorzano-Mier MP. Planetary Protection Knowledge Gap Closure Enabling Crewed Missions to Mars. ASTROBIOLOGY 2024; 24:230-274. [PMID: 38507695 DOI: 10.1089/ast.2023.0092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
As focus for exploration of Mars transitions from current robotic explorers to development of crewed missions, it remains important to protect the integrity of scientific investigations at Mars, as well as protect the Earth's biosphere from any potential harmful effects from returned martian material. This is the discipline of planetary protection, and the Committee on Space Research (COSPAR) maintains the consensus international policy and guidelines on how this is implemented. Based on National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) studies that began in 2001, COSPAR adopted principles and guidelines for human missions to Mars in 2008. At that point, it was clear that to move from those qualitative provisions, a great deal of work and interaction with spacecraft designers would be necessary to generate meaningful quantitative recommendations that could embody the intent of the Outer Space Treaty (Article IX) in the design of such missions. Beginning in 2016, COSPAR then sponsored a multiyear interdisciplinary meeting series to address planetary protection "knowledge gaps" (KGs) with the intent of adapting and extending the current robotic mission-focused Planetary Protection Policy to support the design and implementation of crewed and hybrid exploration missions. This article describes the outcome of the interdisciplinary COSPAR meeting series, to describe and address these KGs, as well as identify potential paths to gap closure. It includes the background scientific basis for each topic area and knowledge updates since the meeting series ended. In particular, credible solutions for KG closure are described for the three topic areas of (1) microbial monitoring of spacecraft and crew health; (2) natural transport (and survival) of terrestrial microbial contamination at Mars, and (3) the technology and operation of spacecraft systems for contamination control. The article includes a KG data table on these topic areas, which is intended to be a point of departure for making future progress in developing an end-to-end planetary protection requirements implementation solution for a crewed mission to Mars. Overall, the workshop series has provided evidence of the feasibility of planetary protection implementation for a crewed Mars mission, given (1) the establishment of needed zoning, emission, transport, and survival parameters for terrestrial biological contamination and (2) the creation of an accepted risk-based compliance approach for adoption by spacefaring actors including national space agencies and commercial/nongovernment organizations.
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Affiliation(s)
| | | | - Corien Bakermans
- Department of Biology, Penn. State University (Altoona), Altoona, Pennsylvania, USA
| | - David W Beaty
- Jet Propulsion Laboratory/California Institute of Technology, Pasadena, California, USA
| | | | | | - Rosalba Bonaccorsi
- SETI Institute, Mountain View, California, USA
- NASA Ames Research Center, Moffett Field, California, USA
| | | | - David A Coil
- School of Medicine, University of California, Davis, Davis, California, USA
| | | | - Peter T Doran
- Department of Geology & Geophysics, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Lori Fenton
- SETI Institute, Mountain View, California, USA
| | - David P Fidler
- Council on Foreign Relations, Washington, District of Columbia, USA
| | - Brian Glass
- NASA Ames Research Center, Moffett Field, California, USA
| | | | - Fathi Karouia
- NASA Ames Research Center, Moffett Field, California, USA
| | - Joel S Levine
- College of William & Mary, Williamsburg, Virginia, USA
| | | | - Javier Martin-Torres
- School of Geoscience, University of Aberdeen, Aberdeen, United Kingdom
- Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Armilla, Spain
| | - Rakesh Mogul
- California Polytechnic (Pomona), Pomona, California, USA
| | - Karen Olsson-Francis
- School of Environment, Earth and Ecosystem Sciences, Open University, Milton Keynes, United Kingdom
| | | | - Manish R Patel
- School of Environment, Earth and Ecosystem Sciences, Open University, Milton Keynes, United Kingdom
| | - David A Pearce
- Department of Applied Sciences, Northumbria University, Newcastle Upon Tyne, United Kingdom
| | | | | | | | - John D Rummel
- Friday Harbor Associates LLC, Friday Harbor, Washington, USA
| | | | - Andrew C Schuerger
- Department of Plant Pathology, University of Florida, Merritt Island, Florida, USA
| | | | - Matthew Sharkey
- US Department of Health & Human Services, Washington, District of Columbia, USA
| | - Nitin K Singh
- Jet Propulsion Laboratory/California Institute of Technology, Pasadena, California, USA
| | | | | | - Carol R Stoker
- NASA Ames Research Center, Moffett Field, California, USA
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Quraish SN, Cockell C, Wuchter C, Kring D, Grice K, Coolen MJL. Deep subsurface microbial life in impact-altered Late Paleozoic granitoid rocks from the Chicxulub impact crater. GEOBIOLOGY 2024; 22:e12583. [PMID: 38385599 DOI: 10.1111/gbi.12583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 11/30/2023] [Accepted: 12/06/2023] [Indexed: 02/23/2024]
Abstract
In 2016, IODP-ICDP Expedition 364 recovered an 829-meter-long core within the peak ring of the Chicxulub impact crater (Yucatán, Mexico), allowing us to investigate the post-impact recovery of the heat-sterilized deep continental microbial biosphere at the impact site. We recently reported increased cell biomass in the impact suevite, which was deposited within the first few hours of the Cenozoic, and that the overall microbial communities differed significantly between the suevite and the other main core lithologies (i.e., the granitic basement and the overlying Early Eocene marine sediments; Cockell et al., 2021). However, only seven rock intervals were previously analyzed from the geologically heterogenic and impact-deformed 587-m-long granitic core section below the suevite interval. Here, we used 16S rRNA gene profiling to study the microbial community composition in 45 intervals including (a) 31 impact-shocked granites, (b) 7 non-granitic rocks (i.e., consisting of suevite and impact melt rocks intercalated into the granites during crater formation and strongly serpentinized pre-impact sub-volcanic, ultramafic basanite/dolerite), and (c) 7 cross-cut mineral veins of anhydride and silica. Most recovered microbial taxa resemble those found in hydrothermal systems. Spearman correlation analysis confirmed that the borehole temperature, which gradually increased from 47 to 69°C with core depth, significantly shaped a subset of the vertically stratified modern microbial community composition in the granitic basement rocks. However, bacterial communities differed significantly between the impoverished shattered granites and nutrient-enriched non-granite rocks, even though both lithologies were at similar depths and temperatures. Furthermore, Spearman analysis revealed a strong correlation between the microbial communities and bioavailable chemical compounds and suggests the presence of chemolithoautotrophs, which most likely still play an active role in metal and sulfur cycling. These results indicate that post-impact microbial niche separation has also occurred in the granitic basement lithologies, as previously shown for the newly formed lithologies. Moreover, our data suggest that the impact-induced geochemical boundaries continue to shape the modern-day deep biosphere in the granitic basement underlying the Chicxulub crater.
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Affiliation(s)
- Sohaib Naseer Quraish
- The Institute for Geoscience Research, WA-Organic and Isotope Geochemistry Centre (WA-OIGC), School of Earth and Planetary Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Charles Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Cornelia Wuchter
- The Institute for Geoscience Research, WA-Organic and Isotope Geochemistry Centre (WA-OIGC), School of Earth and Planetary Sciences, Curtin University, Bentley, Western Australia, Australia
| | - David Kring
- Lunar and Planetary Institute, Houston, Texas, USA
| | - Kliti Grice
- The Institute for Geoscience Research, WA-Organic and Isotope Geochemistry Centre (WA-OIGC), School of Earth and Planetary Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Marco J L Coolen
- The Institute for Geoscience Research, WA-Organic and Isotope Geochemistry Centre (WA-OIGC), School of Earth and Planetary Sciences, Curtin University, Bentley, Western Australia, Australia
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3
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Moreno-Paz M, dos Santos Severino RS, Sánchez-García L, Manchado JM, García-Villadangos M, Aguirre J, Fernández-Martínez MA, Carrizo D, Kobayashi L, Dave A, Warren-Rhodes K, Davila A, Stoker CR, Glass B, Parro V. Life Detection and Microbial Biomarker Profiling with Signs of Life Detector-Life Detector Chip During a Mars Drilling Simulation Campaign in the Hyperarid Core of the Atacama Desert. ASTROBIOLOGY 2023; 23:1259-1283. [PMID: 37930382 PMCID: PMC10825288 DOI: 10.1089/ast.2021.0174] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 07/02/2023] [Indexed: 11/07/2023]
Abstract
The low organic matter content in the hyperarid core of the Atacama Desert, together with abrupt temperature shifts and high ultraviolet radiation at its surface, makes this region one of the best terrestrial analogs of Mars and one of the best scenarios for testing instrumentation devoted to in situ planetary exploration. We have operated remotely and autonomously the SOLID-LDChip (Signs of Life Detector-Life Detector Chip), an antibody microarray-based sensor instrument, as part of a rover payload during the 2019 NASA Atacama Rover Astrobiology Drilling Studies (ARADS) Mars drilling simulation campaign. A robotic arm collected drilled cuttings down to 80 cm depth and loaded SOLID to process and assay them with LDChip for searching for molecular biomarkers. A remote science team received and analyzed telemetry data and LDChip results. The data revealed the presence of microbial markers from Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Firmicutes, and Cyanobacteria to be relatively more abundant in the middle layer (40-50 cm). In addition, the detection of several proteins from nitrogen metabolism indicates a pivotal role in the system. These findings were corroborated and complemented on "returned samples" to the lab by a comprehensive analysis that included DNA sequencing, metaproteomics, and a metabolic reconstruction of the sampled area. Altogether, the results describe a relatively complex microbial community with members capable of nitrogen fixation and denitrification, sulfur oxidation and reduction, or triggering oxidative stress responses, among other traits. This remote operation demonstrated the high maturity of SOLID-LDChip as a powerful tool for remote in situ life detection for future missions in the Solar System.
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Affiliation(s)
- Mercedes Moreno-Paz
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
| | - Rita Sofia dos Santos Severino
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
- Departament of Física y Matemáticas y de Automática, University of Alcalá de Henares (UAH), Madrid, Spain
| | - Laura Sánchez-García
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
| | - Juan Manuel Manchado
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
| | | | - Jacobo Aguirre
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
| | - Miguel Angel Fernández-Martínez
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
- Department of Natural Resource Sciences, McGill University, Québec, Canada
| | - Daniel Carrizo
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
| | - Linda Kobayashi
- Space Science Division and Astrobiology Division, NASA Ames Research Center, Moffett Field, California, USA
| | - Arwen Dave
- Space Science Division and Astrobiology Division, NASA Ames Research Center, Moffett Field, California, USA
| | - Kim Warren-Rhodes
- Space Science Division and Astrobiology Division, NASA Ames Research Center, Moffett Field, California, USA
- Carl Sagan Center, SETI Institute, Mountain View, California, USA
| | - Alfonso Davila
- Space Science Division and Astrobiology Division, NASA Ames Research Center, Moffett Field, California, USA
| | - Carol R. Stoker
- Space Science Division and Astrobiology Division, NASA Ames Research Center, Moffett Field, California, USA
| | - Brian Glass
- Space Science Division and Astrobiology Division, NASA Ames Research Center, Moffett Field, California, USA
| | - Víctor Parro
- Department of Molecular Evolution, Centro de Astrobiología (CAB), INTA-CSIC, Madrid, Spain
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Osterhout JT, Schopf JW, Kudryavtsev AB, Czaja AD, Williford KH. Deep-UV Raman Spectroscopy of Carbonaceous Precambrian Microfossils: Insights into the Search for Past Life on Mars. ASTROBIOLOGY 2022; 22:1239-1254. [PMID: 36194869 DOI: 10.1089/ast.2021.0135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The current strategy for detecting evidence of ancient life on Mars-a primary goal of NASA's ongoing Mars 2020 mission-is based largely on knowledge of Precambrian life and of its preservation in Earth's early rock record. The fossil record of primitive microorganisms consists mainly of stromatolites and other microbially influenced sedimentary structures, which occasionally preserve microfossils or other geochemical traces of life. Raman spectroscopy is an invaluable tool for identifying such signs of life and is routinely performed on Precambrian microfossils to help establish their organic composition, degree of thermal maturity, and biogenicity. The Mars 2020 rover, Perseverance, is equipped with a deep-ultraviolet (UV) Raman spectrometer as part of the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) instrument, which will be used in part to characterize the preservation of organic matter in the ancient sedimentary rocks of Jezero crater and therein search for possible biosignatures. To determine the deep-UV Raman spectra characteristic of ancient microbial fossils, this study analyzes individual microfossils from 14 Precambrian cherts using deep-UV (244 nm) Raman spectroscopy. Spectra obtained were measured and calibrated relative to a graphitic standard and categorized according to the morphology and depositional environment of the fossil analyzed and its Raman-indicated thermal maturity. All acquired spectra of the fossil kerogens include a considerably Raman-enhanced and prominent first-order Raman G-band (∼1600 cm-1), whereas its commonly associated D-band (∼1350 cm-1) is restricted to specimens of lower thermal maturity (below greenschist facies) that thus have the less altered biosignature indicative of relatively well-preserved organic matter. If comparably preserved, similar characteristics would be expected to be exhibited by microfossils or ancient organic matter in rock samples collected and cached on Mars in preparation for future sample return to Earth.
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Affiliation(s)
- Jeffrey T Osterhout
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California, USA
- Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles, California, USA
| | - J William Schopf
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California, USA
- Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles, California, USA
| | - Anatoliy B Kudryavtsev
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California, USA
- Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles, California, USA
| | - Andrew D Czaja
- Department of Geology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kenneth H Williford
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
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Robinson A, Ulrich SM. Haloferax volcanii Remains Viable and Shows Morphological Changes under Anoxic (CO 2-Enriched) and Hypobaric (2.4 kPa) Atmospheric Conditions. ASTROBIOLOGY 2022; 22:829-837. [PMID: 35325555 DOI: 10.1089/ast.2021.0076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Potentially habitable zones have been discovered on Mars today in underground areas containing perchlorate brines. Understanding the low-pressure adaptations of microorganisms is essential in learning more about what life could potentially be found on Mars today or could have existed in the distant past. Many studies have looked at low-pressure adaptations in bacteria; however, studies aimed at understanding these adaptations in archaea are scarcer. Haloferax volcanii is a species of halophilic archaea documented to tolerate high concentrations of oxidizing agents present on Mars (i.e., perchlorates and nitrates). In this study, we expose H. volcanii to a hypobaric (2.4 kPa) and an anoxic CO2-enriched atmosphere in the presence of perchlorate, chlorate, and nitrate. While no growth was observed during incubation in these conditions, survivability was increased in cultures incubated in low-pressure atmospheric conditions compared to ambient Earth atmospheric pressures. Scanning electron microscopy observations showed morphological changes in low-pressure conditions not observed at ambient Earth atmospheric pressures. Results suggest that previously undocumented low-pressure adaptations in H. volcanii increase survivability in simulated subsurface martian conditions. Future experiments to understand the changes in gene expression under these conditions may be valuable to understand more about low-pressure adaptations in archaea.
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Affiliation(s)
- Adam Robinson
- Department of Natural Science, St. Petersburg College, Clearwater, Florida, USA
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6
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Méndez A, Rivera-Valentín EG, Schulze-Makuch D, Filiberto J, Ramírez RM, Wood TE, Dávila A, McKay C, Ceballos KNO, Jusino-Maldonado M, Torres-Santiago NJ, Nery G, Heller R, Byrne PK, Malaska MJ, Nathan E, Simões MF, Antunes A, Martínez-Frías J, Carone L, Izenberg NR, Atri D, Chitty HIC, Nowajewski-Barra P, Rivera-Hernández F, Brown CY, Lynch KL, Catling D, Zuluaga JI, Salazar JF, Chen H, González G, Jagadeesh MK, Haqq-Misra J. Habitability Models for Astrobiology. ASTROBIOLOGY 2021; 21:1017-1027. [PMID: 34382857 DOI: 10.1089/ast.2020.2342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales. Astrobiologists have been proposing different habitability models for some time, with little integration and consistency among them, being different in function to those used by ecologists. Habitability models are not only used to determine whether environments are habitable, but they also are used to characterize what key factors are responsible for the gradual transition from low to high habitability states. Here we review and compare some of the different models used by ecologists and astrobiologists and suggest how they could be integrated into new habitability standards. Such standards will help improve the comparison and characterization of potentially habitable environments, prioritize target selections, and study correlations between habitability and biosignatures. Habitability models are the foundation of planetary habitability science, and the synergy between ecologists and astrobiologists is necessary to expand our understanding of the habitability of Earth, the Solar System, and extrasolar planets.
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Affiliation(s)
- Abel Méndez
- Planetary Habitability Laboratory, University of Puerto Rico at Arecibo, Puerto Rico, USA
| | | | - Dirk Schulze-Makuch
- Center for Astronomy and Astrophysics, Technische Universität Berlin, Berlin, Germany; German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany; Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Stechlin, Germany
| | | | - Ramses M Ramírez
- University of Central Florida, Department of Physics, Orlando, Florida, USA; Space Science Institute, Boulder, Colorado, USA
| | - Tana E Wood
- USDA Forest Service International Institute of Tropical Forestry, San Juan, Puerto Rico, USA
| | - Alfonso Dávila
- NASA Ames Research Center, Moffett Field, California, USA
| | - Chris McKay
- NASA Ames Research Center, Moffett Field, California, USA
| | - Kevin N Ortiz Ceballos
- Planetary Habitability Laboratory, University of Puerto Rico at Arecibo, Puerto Rico, USA
| | | | | | | | - René Heller
- Max Planck Institute for Solar System Research; Institute for Astrophysics, University of Göttingen, Germany
| | - Paul K Byrne
- North Carolina State University, Raleigh, North Carolina, USA
| | - Michael J Malaska
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Erica Nathan
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island, USA
| | - Marta Filipa Simões
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Taipa, Macau SAR, China
| | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Taipa, Macau SAR, China
| | | | | | - Noam R Izenberg
- Johns Hopkins Applied Physics Laboratory, Laurel, Maryland, USA
| | - Dimitra Atri
- Center for Space Science, New York University Abu Dhabi, United Arab Emirates
| | | | | | | | | | - Kennda L Lynch
- Lunar and Planetary Institute, USRA, Houston, Texas, USA
| | | | - Jorge I Zuluaga
- Institute of Physics / FCEN - Universidad de Antioquia, Medellín, Colombia
| | - Juan F Salazar
- GIGA, Escuela Ambiental, Facultad de Ingeniería, Universidad de Antioquia, Medellín, Colombia
| | - Howard Chen
- Northwestern University, Evanston, Illinois, USA
| | - Grizelle González
- USDA Forest Service International Institute of Tropical Forestry, San Juan, Puerto Rico, USA
| | | | - Jacob Haqq-Misra
- Blue Marble Space Institute of Science, Seattle, Washington, USA
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Schwendner P, Nguyen AN, Schuerger AC. Use of NanoSIMS to Identify the Lower Limits of Metabolic Activity and Growth by Serratia liquefaciens Exposed to Sub-Zero Temperatures. Life (Basel) 2021; 11:life11050459. [PMID: 34065549 PMCID: PMC8161314 DOI: 10.3390/life11050459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/12/2021] [Accepted: 05/19/2021] [Indexed: 11/16/2022] Open
Abstract
Serratia liquefaciens is a cold-adapted facultative anaerobic astrobiology model organism with the ability to grow at a Martian atmospheric pressure of 7 hPa. Currently there is a lack of data on its limits of growth and metabolic activity at sub-zero temperatures found in potential habitable regions on Mars. Growth curves and nano-scale secondary ion mass spectrometry (NanoSIMS) were used to characterize the growth and metabolic threshold for S. liquefaciens ATCC 27,592 grown at and below 0 °C. Cells were incubated in Spizizen medium containing three stable isotopes substituting their unlabeled counterparts; i.e., 13C-glucose, (15NH4)2SO4, and H218O; at 0, −1.5, −3, −5, −10, or −15 °C. The isotopic ratios of 13C/12C, 15N/14N, and 18O/16O and their corresponding fractions were determined for 240 cells. NanoSIMS results revealed that with decreasing temperature the cellular amounts of labeled ions decreased indicating slower metabolic rates for isotope uptake and incorporation. Metabolism was significantly reduced at −1.5 and −3 °C, almost halted at −5 °C, and shut-down completely at or below −10 °C. While growth was observed at 0 °C after 5 days, samples incubated at −1.5 and −3 °C exhibited significantly slower growth rates until growth was detected at 70 days. In contrast, cell densities decreased by at least half an order of magnitude over 70 days in cultures incubated at ≤ −5 °C. Results suggest that S. liquefaciens, if transported to Mars, might be able to metabolize and grow in shallow sub-surface niches at temperatures above −5 °C and might survive—but not grow—at temperatures below −5 °C.
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Affiliation(s)
- Petra Schwendner
- Space Life Sciences Lab, Department of Plant Pathology, University of Florida, 505 Odyssey Way, Exploration Park, Merritt Island, FL 32953, USA;
- Correspondence:
| | - Ann N. Nguyen
- Jacobs, NASA Johnson Space Center, Houston, TX 77058, USA;
| | - Andrew C. Schuerger
- Space Life Sciences Lab, Department of Plant Pathology, University of Florida, 505 Odyssey Way, Exploration Park, Merritt Island, FL 32953, USA;
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8
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Seaton KM, Cable ML, Stockton AM. Analytical Chemistry in Astrobiology. Anal Chem 2021; 93:5981-5997. [PMID: 33835785 DOI: 10.1021/acs.analchem.0c04271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This Feature introduces and discusses the findings of key analytical techniques used to study planetary bodies in our solar system in the search for life beyond Earth, future missions planned for high-priority astrobiology targets in our solar system, and the challenges we face in performing these investigations.
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Affiliation(s)
- Kenneth Marshall Seaton
- School of Chemistry & Biochemistry, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
| | - Morgan Leigh Cable
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Amanda Michelle Stockton
- School of Chemistry & Biochemistry, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
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9
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Abstract
Astrobiology is focused on the study of life in the universe. However, lifeless planetary environments yield biological information on the variety of ways in which physical and chemical conditions in the universe preclude the possibility of the origin or persistence of life, and in turn this will help explain the distribution and abundance of life, or lack of it, in the universe. Furthermore, many places that humans wish to explore and settle in space are lifeless, and studying the fate of life in these environments will aid our own success in thriving in them. In this synthetic review, I have three objectives, as follows: (1) To discuss the biological value and use of lifeless environments, (2) To explore the diverse planetary bodies and environments that can be lifeless and to categorize them, and (3) To propose sets of biological experiments that can be undertaken in different categories of lifeless worlds and environments and suggest concepts for mission ideas to realize these goals. They include origin of life and microbial inoculation experiments in lifeless but habitable environments. I suggest that the biological study of lifelessness is an underappreciated area in planetary sciences.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
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Cockell CS, Wordsworth R, Whiteford N, Higgins PM. Minimum Units of Habitability and Their Abundance in the Universe. ASTROBIOLOGY 2021; 21:481-489. [PMID: 33513037 DOI: 10.1089/ast.2020.2350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Although the search for habitability is a much-vaunted objective in the study of planetary environments, the material requirements for an environment to be habitable can be met with relatively few ingredients. In this hypothesis paper, the minimum material requirements for habitability are first re-evaluated, necessarily based on life "as we know it." From this vantage point, we explore examples of the minimum number of material requirements for habitable conditions to arise in a planetary environment, which we illustrate with "minimum habitability diagrams." These requirements raise the hypothesis that habitable conditions may be common throughout the universe. If the hypothesis was accepted, then the discovery of life would remain an important discovery, but habitable conditions on their own would be an unremarkable feature of the material universe. We discuss how minimum units of habitability provide a parsimonious way to consider the minimum number of geological inferences about a planetary body, and the minimum number of atmospheric components that must be measured, for example in the case of exoplanets, to be able to make assessments of habitability.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Robin Wordsworth
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, USA
| | - Niall Whiteford
- Institute for Astronomy, Royal Observatory, Blackford Hill, Edinburgh, UK
| | - Peter M Higgins
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- Institute for Astronomy, Royal Observatory, Blackford Hill, Edinburgh, UK
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Rizzo V, Armstrong R, Hua H, Cantasano N, Nicolò T, Bianciardi G. Life on Mars: Clues, Evidence or Proof? SOLAR PLANETS AND EXOPLANETS [WORKING TITLE] 2021. [DOI: 10.5772/intechopen.95531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/23/2023]
Abstract
The search for life on Mars is one of the main objectives of space missions. At “Pahrump Hills Field Site” (Gale Crater, Mojave target), inside the mudstones of the Murray lacustrine sequence, Curiosity rover found organic materials and lozenge shaped laths considered by NASA as pseudomorphic crystals. Besides it detected mineral assemblages suggesting both oxidizing (hematite) and reducing (magnetite) environments, as well as acidic (diagenetic and/or authigenic jarosite) and neutral (apatite) conditions, that might suggest bacterially mediated reactions. Our morphological and morphometrical investigations show that such diagenetic microstructures are unlikely to be lozenge shapes and, in addition to several converging features, they suggest the presence of remnants of complex algal-like biota, similar to terrestrial procaryotes and/or eukaryotes; possible microorganisms that, on the base of absolute dating criteria used by other scholars, lived on Mars about 2.12 +/−0.36 Ga ago.
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Carrier B, Beaty D, Meyer M, Blank J, Chou L, DasSarma S, Des Marais D, Eigenbrode J, Grefenstette N, Lanza N, Schuerger A, Schwendner P, Smith H, Stoker C, Tarnas J, Webster K, Bakermans C, Baxter B, Bell M, Benner S, Bolivar Torres H, Boston P, Bruner R, Clark B, DasSarma P, Engelhart A, Gallegos Z, Garvin Z, Gasda P, Green J, Harris R, Hoffman M, Kieft T, Koeppel A, Lee P, Li X, Lynch K, Mackelprang R, Mahaffy P, Matthies L, Nellessen M, Newsom H, Northup D, O'Connor B, Perl S, Quinn R, Rowe L, Sauterey B, Schneegurt M, Schulze-Makuch D, Scuderi L, Spilde M, Stamenković V, Torres Celis J, Viola D, Wade B, Walker C, Wiens R, Williams A, Williams J, Xu J. Mars Extant Life: What's Next? Conference Report. ASTROBIOLOGY 2020; 20:785-814. [PMID: 32466662 PMCID: PMC7307687 DOI: 10.1089/ast.2020.2237] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/24/2020] [Indexed: 05/19/2023]
Abstract
On November 5-8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The conference gathered a community of actively publishing experts in disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset of conference attendees concluded that there is a realistic possibility that Mars hosts indigenous microbial life. A powerful theme that permeated the conference is that the key to the search for martian extant life lies in identifying and exploring refugia ("oases"), where conditions are either permanently or episodically significantly more hospitable than average. Based on our existing knowledge of Mars, conference participants highlighted four potential martian refugium (not listed in priority order): Caves, Deep Subsurface, Ices, and Salts. The conference group did not attempt to reach a consensus prioritization of these candidate environments, but instead felt that a defensible prioritization would require a future competitive process. Within the context of these candidate environments, we identified a variety of geological search strategies that could narrow the search space. Additionally, we summarized a number of measurement techniques that could be used to detect evidence of extant life (if present). Again, it was not within the scope of the conference to prioritize these measurement techniques-that is best left for the competitive process. We specifically note that the number and sensitivity of detection methods that could be implemented if samples were returned to Earth greatly exceed the methodologies that could be used at Mars. Finally, important lessons to guide extant life search processes can be derived both from experiments carried out in terrestrial laboratories and analog field sites and from theoretical modeling.
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Affiliation(s)
- B.L. Carrier
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - D.W. Beaty
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - J.G. Blank
- NASA Ames Research Center, Moffett Field, California, USA
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - L. Chou
- Georgetown University, Washington, DC, USA
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - S. DasSarma
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | - N.L. Lanza
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - A.C. Schuerger
- University of Florida/Space Life Sciences Laboratory, Kennedy Space Center, Florida, USA
| | - P. Schwendner
- University of Florida/Space Life Sciences Laboratory, Kennedy Space Center, Florida, USA
| | - H.D. Smith
- NASA Ames Research Center, Moffett Field, California, USA
| | - C.R. Stoker
- NASA Ames Research Center, Moffett Field, California, USA
| | - J.D. Tarnas
- Brown University, Providence, Rhode Island, USA
| | - K.D. Webster
- Planetary Science Institute, Tucson, Arizona, USA
| | - C. Bakermans
- Pennsylvania State University, Altoona, Pennsylvania, USA
| | - B.K. Baxter
- Westminster College, Salt Lake City, Utah, USA
| | - M.S. Bell
- NASA Johnson Space Center, Houston, Texas, USA
| | - S.A. Benner
- Foundation for Applied Molecular Evolution, Alachua, Florida, USA
| | - H.H. Bolivar Torres
- Universidad Nacional Autonoma de Mexico, Coyoacan, Distrito Federal Mexico, Mexico
| | - P.J. Boston
- NASA Astrobiology Institute, NASA Ames Research Center, Moffett Field, California, USA
| | - R. Bruner
- Denver Museum of Nature and Science, Denver, Colorado, USA
| | - B.C. Clark
- Space Science Institute, Littleton, Colorado, USA
| | - P. DasSarma
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Z.E. Gallegos
- University of New Mexico, Albuquerque, New Mexico, USA
| | - Z.K. Garvin
- Princeton University, Princeton, New Jersey, USA
| | - P.J. Gasda
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - J.H. Green
- Texas Tech University, Lubbock, Texas, USA
| | - R.L. Harris
- Princeton University, Princeton, New Jersey, USA
| | - M.E. Hoffman
- University of New Mexico, Albuquerque, New Mexico, USA
| | - T. Kieft
- New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
| | | | - P.A. Lee
- College of Charleston, Charleston, South Carolina, USA
| | - X. Li
- University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - K.L. Lynch
- Lunar and Planetary Institute/USRA, Houston, Texas, USA
| | - R. Mackelprang
- California State University Northridge, Northridge, California, USA
| | - P.R. Mahaffy
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - L.H. Matthies
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - H.E. Newsom
- University of New Mexico, Albuquerque, New Mexico, USA
| | - D.E. Northup
- University of New Mexico, Albuquerque, New Mexico, USA
| | | | - S.M. Perl
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - R.C. Quinn
- NASA Ames Research Center, Moffett Field, California, USA
| | - L.A. Rowe
- Valparaiso University, Valparaiso, Indiana, USA
| | | | | | | | - L.A. Scuderi
- University of New Mexico, Albuquerque, New Mexico, USA
| | - M.N. Spilde
- University of New Mexico, Albuquerque, New Mexico, USA
| | - V. Stamenković
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - J.A. Torres Celis
- Universidad Nacional Autonoma de Mexico, Coyoacan, Distrito Federal Mexico, Mexico
| | - D. Viola
- NASA Ames Research Center, Moffett Field, California, USA
| | - B.D. Wade
- Michigan State University, East Lansing, Michigan, USA
| | - C.J. Walker
- Delaware State University, Dover, Delaware, USA
| | - R.C. Wiens
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | - J.M. Williams
- University of New Mexico, Albuquerque, New Mexico, USA
| | - J. Xu
- University of Texas, El Paso, Texas, USA
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The Hypopiezotolerant Bacterium, Serratia liquefaciens, Failed to Grow in Mars Analog Soils under Simulated Martian Conditions at 7 hPa. Life (Basel) 2020; 10:life10060077. [PMID: 32466370 PMCID: PMC7344922 DOI: 10.3390/life10060077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/13/2020] [Accepted: 05/20/2020] [Indexed: 12/16/2022] Open
Abstract
The search for life on Mars is predicated on the idea that Earth and Mars life (if present) should be both carbon- and water-based with similar forms of evolution. However, the astrobiology community can currently only investigate plausible Martian microbial ecosystems by using Terran life-forms as proxies. In order to examine how life might persist on Mars, we used a hypopiezotolerant bacterium (def., able to grow at 7-10 hPa)-Serratia liquefaciens-in growth assays with four Mars analog soils conducted under a subset of simulated Martian conditions including 7 hPa, 0 °C, and a CO2-enriched anoxic atmosphere (called low-PTA conditions). The four Mars analog soils included an Aeolian dust analog, the Mars JSC-1 analog, a Phoenix lander-site simulant, and a high-Salts analog. Serratia liquefaciens cells were able to grow at 30 °C in a liquid minimal basal medium (MBM) supplemented with 10- or 20-mM sucrose, Spizizen salts, and micronutrients. When the four analog soils were doped with both MBM and cells of S. liquefaciens, and subsequently incubated at 30 °C for 72 h, cell densities increased between 2-logs (Phoenix analog) and 4-logs (Aeolian and JSC-1 analogs); the Salts analog led to complete inactivation of S. liquefaciens within 24 h. In contrast, when the experiment was repeated, but incubated under low-PTA conditions, S. liquefaciens cells were either killed immediately by the Salts analog, or decreased by > 5 logs over 28 d by the Aeolian, JSC-1, and Phoenix analogs. The failure of S. liquefaciens to grow in the analog soils under low-PTA conditions was attributed to the synergistic interactions among six factors (i.e., low pressure, low temperature, anoxic atmosphere (i.e., the low-PTA conditions), low-pH in the Salts soil, dissolved salts in all analogs, and oligotrophic conditions) that increased the biocidal or inhibitory conditions within the analog soils. Results suggest that even if a hypopiezotolerant Terran microbe is displaced from a spacecraft surface on Mars, and lands in a hydrated and nutrient-rich niche, growth in the Martian regolith is not automatically assured.
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14
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Cockell CS. Persistence of Habitable, but Uninhabited, Aqueous Solutions and the Application to Extraterrestrial Environments. ASTROBIOLOGY 2020; 20:617-627. [PMID: 32105517 DOI: 10.1089/ast.2019.2179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In most environments on Earth, habitable environments contain life. Experiments were conducted to investigate the decoupling of the presence of habitable conditions and life. A set of microcosms habitable for known groups of organisms, but uninhabited (i.e., uninhabited habitats), was exposed to external environmental conditions to test the hypothesis that extreme habitable environments can remain uninhabited for sustained time periods. These microcosms were made of tubes containing liquid water and inorganic N, P, and S. Organics (used as electron donors and as a C source) were provided as L and D amino acids. One set of uninhabited habitats contained no additional salts, one set contained saturated NaCl, and one set contained saturated MgSO4. A ddH2O control and a complex medium for Halobacterium were used as controls. The presence of organisms was tested by enumeration of colonists and sequencing of extracted DNA. At each time point, inoculation into fresh medium was used to test for growth of organisms. After 1 week, the "no salt" and saturated MgSO4 solutions were colonized. After 6 months, both the NaCl-saturated and Halobacterium solutions remained uninhabited, but all other samples were colonized. These experiments demonstrate that certain types of habitable liquid water environments exposed to microbial atmospheric inoculation, even on Earth, can remain devoid of reproducing life for many months. On other planetary bodies, such as Mars, these data imply the possibility of preserved transient water bodies that would record habitable conditions, but no evidence of life, even if life existed elsewhere on the planet.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, James Clerk Maxwell Building, The King's Buildings, University of Edinburgh, Edinburgh, United Kingdom
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15
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Thomson SD, Quinn RC, Ricco AJ, Koehne JE. Electrochemistry for Life Detection on Ocean Worlds. ChemElectroChem 2020. [DOI: 10.1002/celc.201901683] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Seamus D. Thomson
- NASA Postdoctoral ProgramNASA Ames Research Center Moffett Field, California 94035 USA
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16
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Lam BR, Barge LM, Noell AC, Nealson KH. Detecting Endogenous Microbial Metabolism and Differentiating Between Abiotic and Biotic Signals Observed by Bioelectrochemical Systems in Soils. ASTROBIOLOGY 2020; 20:39-52. [PMID: 31560219 DOI: 10.1089/ast.2018.1892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Unambiguous detection of chemical and physical signatures of microbial life on Mars or other solar system bodies requires differentiation between signals produced by biotic and abiotic processes; instruments aimed at generalized in situ extant life detection would therefore increase the science return of a life-detection mission. Here, we investigate Bioelectrochemical Systems (BES) as a technique to measure microbial metabolism (which produces electrical current and redox changes) and distinguish between potential abiotic and biotic responses in environmental samples. Samples from inhabited niches should contain everything necessary to produce current, that is, catalysts (microorganisms) and fuel (nutrients). BES can also probe for inactive organisms in less energetically rich areas by adding a fuel to drive metabolism. A commercial potting soil and a Mars simulant soil were inoculated in the anodic chamber of microbial fuel cells, and current was monitored over time. Addition of a fuel (electron donor) source was tested for metabolic stimulation of endogenous microbes. Redox reactions between Mars simulant soil and the introduced electron donor (lactate) produced false-positive results, emphasizing the importance of careful interpretation of signals obtained. The addition of lactate to both soils resulted in enhanced biologically produced current, allowing stimulation and detection of dormant microbes. Our results demonstrate that BES provide an approach to detect metabolism in samples without prior knowledge of the organisms present, and that thorough electrochemical analyses and experimental design are necessary to determine if signals are biotic.
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Affiliation(s)
- Bonita R Lam
- Department of Biological Sciences, University of Southern California, Los Angeles, California
| | - Laura M Barge
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Aaron C Noell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Kenneth H Nealson
- Department of Biological Sciences, University of Southern California, Los Angeles, California
- Department of Earth Sciences, University of Southern California, Los Angeles, California
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17
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Microbial Markers Profile in Anaerobic Mars Analogue Environments Using the LDChip (Life Detector Chip) Antibody Microarray Core of the SOLID (Signs of Life Detector) Platform. Microorganisms 2019; 7:microorganisms7090365. [PMID: 31540500 PMCID: PMC6780502 DOI: 10.3390/microorganisms7090365] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/30/2019] [Accepted: 09/16/2019] [Indexed: 11/30/2022] Open
Abstract
One of the main objectives for astrobiology is to unravel and explore the habitability of environments beyond Earth, paying special attention to Mars. If the combined environmental stress factors on Mars are compatible with life or if they were less harsh in the past, to investigate the traces of past or present life is critical to understand its potential habitability. Essential for this research is the characterization of Mars analogue environments on Earth through the development of techniques for biomarker detection in them. Biosensing techniques based on fluorescence sandwich microarray immunoassays (FSMI) have shown to be a powerful tool to detect biosignatures and depict the microbial profiles of different environments. In this study, we described the microbial biomarker profile of five anoxic Mars analogues sites using the Life Detector Chip (LDChip), an antibody microarray for multiple microbial marker detection. Furthermore, we contributed to new targets by developing a new 26-polyclonal antibodies microarray using crude extracts from anaerobic sampling sites, halophilic microorganisms, and anaerobic isolates obtained in the framework of the European Mars Analogues for Space Exploration (MASE) project. The new subset of antibodies was characterized and implemented into a microarray platform (MASE-Chip) for microbial marker searching in salty and anaerobic environments.
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18
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Mojarro A, Hachey J, Bailey R, Brown M, Doebler R, Ruvkun G, Zuber MT, Carr CE. Nucleic Acid Extraction and Sequencing from Low-Biomass Synthetic Mars Analog Soils for In Situ Life Detection. ASTROBIOLOGY 2019; 19:1139-1152. [PMID: 31204862 PMCID: PMC6708270 DOI: 10.1089/ast.2018.1929] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Recent studies regarding the origins of life and Mars-Earth meteorite transfer simulations suggest that biological informational polymers, such as nucleic acids (DNA and RNA), have the potential to provide unambiguous evidence of life on Mars. To this end, we are developing a metagenomics-based life-detection instrument which integrates nucleic acid extraction and nanopore sequencing: the Search for Extra-Terrestrial Genomes (SETG). Our goal is to isolate and sequence nucleic acids from extant or preserved life on Mars in order to determine if a particular genetic sequence (1) is distantly related to life on Earth, indicating a shared ancestry due to lithological exchange, or (2) is unrelated to life on Earth, suggesting convergent origins of life on Mars. In this study, we validate prior work on nucleic acid extraction from cells deposited in Mars analog soils down to microbial concentrations (i.e., 104 cells in 50 mg of soil) observed in the driest and coldest regions on Earth. In addition, we report low-input nanopore sequencing results from 2 pg of purified Bacillus subtilis spore DNA simulating ideal extraction yields equivalent to 1 ppb life-detection sensitivity. We achieve this by employing carrier sequencing, a method of sequencing sub-nanogram DNA in the background of a genomic carrier. After filtering of carrier, low-quality, and low-complexity reads we detected 5 B. subtilis reads, 18 contamination reads (including Homo sapiens), and 6 high-quality noise reads believed to be sequencing artifacts.
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Affiliation(s)
- Angel Mojarro
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Address correspondence to: Angel Mojarro, Massachusetts Institute of Technology, 77 Massachusetts Ave, Room E25-647, Cambridge, MA 02139
| | | | - Ryan Bailey
- Claremont Biosolutions, LLC, Upland, California
| | - Mark Brown
- Claremont Biosolutions, LLC, Upland, California
| | | | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts
| | - Maria T. Zuber
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Christopher E. Carr
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts
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Cockell CS, Harrison JP, Stevens AH, Payler SJ, Hughes SS, Kobs Nawotniak SE, Brady AL, Elphic R, Haberle CW, Sehlke A, Beaton KH, Abercromby AF, Schwendner P, Wadsworth J, Landenmark H, Cane R, Dickinson AW, Nicholson N, Perera L, Lim DS. A Low-Diversity Microbiota Inhabits Extreme Terrestrial Basaltic Terrains and Their Fumaroles: Implications for the Exploration of Mars. ASTROBIOLOGY 2019; 19:284-299. [PMID: 30840501 PMCID: PMC6442273 DOI: 10.1089/ast.2018.1870] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A major objective in the exploration of Mars is to test the hypothesis that the planet hosted life. Even in the absence of life, the mapping of habitable and uninhabitable environments is an essential task in developing a complete understanding of the geological and aqueous history of Mars and, as a consequence, understanding what factors caused Earth to take a different trajectory of biological potential. We carried out the aseptic collection of samples and comparison of the bacterial and archaeal communities associated with basaltic fumaroles and rocks of varying weathering states in Hawai'i to test four hypotheses concerning the diversity of life in these environments. Using high-throughput sequencing, we found that all these materials are inhabited by a low-diversity biota. Multivariate analyses of bacterial community data showed a clear separation between sites that have active fumaroles and other sites that comprised relict fumaroles, unaltered, and syn-emplacement basalts. Contrary to our hypothesis that high water flow environments, such as fumaroles with active mineral leaching, would be sites of high biological diversity, alpha diversity was lower in active fumaroles compared to relict or nonfumarolic sites, potentially due to high-temperature constraints on microbial diversity in fumarolic sites. A comparison of these data with communities inhabiting unaltered and weathered basaltic rocks in Idaho suggests that bacterial taxon composition of basaltic materials varies between sites, although the archaeal communities were similar in Hawai'i and Idaho. The taxa present in both sites suggest that most of them obtain organic carbon compounds from the atmosphere and from phototrophs and that some of them, including archaeal taxa, cycle fixed nitrogen. The low diversity shows that, on Earth, extreme basaltic terrains are environments on the edge of sustaining life with implications for the biological potential of similar environments on Mars and their exploration by robots and humans.
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Affiliation(s)
- Charles S. Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- Address correspondence to: Charles S. Cockell, School of Physics and Astronomy, University of Edinburgh, King's Buildings, Edinburgh EH9 3JZ, UK
| | - Jesse P. Harrison
- Aquatic Biogeochemistry Research Unit, Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Adam H. Stevens
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Samuel J. Payler
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Scott S. Hughes
- Department of Geosciences, Idaho State University, Pocatello, Idaho, USA
| | | | - Allyson L. Brady
- School of Geography and Earth Sciences, McMaster University, Hamilton, Canada
| | - R.C. Elphic
- NASA Ames Research Center, Mountain View, California, USA
| | | | | | | | - Andrew F.J. Abercromby
- Biomedical Research & Environmental Sciences Division (SK), NASA Johnson Space Center, Houston, Texas, USA
| | - Petra Schwendner
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Jennifer Wadsworth
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Hanna Landenmark
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Rosie Cane
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Andrew W. Dickinson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Natasha Nicholson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Liam Perera
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Darlene S.S. Lim
- NASA Ames Research Center, Mountain View, California, USA
- Bay Area Environmental Research Institute (BAERI), Moffett Field, California, USA
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20
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Serrano P, Alawi M, de Vera JP, Wagner D. Response of Methanogenic Archaea from Siberian Permafrost and Non-permafrost Environments to Simulated Mars-like Desiccation and the Presence of Perchlorate. ASTROBIOLOGY 2019; 19:197-208. [PMID: 30742498 DOI: 10.1089/ast.2018.1877] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Numerous preflight investigations were necessary prior to the exposure experiment BIOMEX on the International Space Station to test the basic potential of selected microorganisms to resist or even to be active under Mars-like conditions. In this study, methanogenic archaea, which are anaerobic chemolithotrophic microorganisms whose lifestyle would allow metabolism under the conditions on early and recent Mars, were analyzed. Some strains from Siberian permafrost environments have shown a particular resistance. In this investigation, we analyzed the response of three permafrost strains (Methanosarcina soligelidi SMA-21, Candidatus Methanosarcina SMA-17, Candidatus Methanobacterium SMA-27) and two related strains from non-permafrost environments (Methanosarcina mazei, Methanosarcina barkeri) to desiccation conditions (-80°C for 315 days, martian regolith analog simulants S-MRS and P-MRS, a 128-day period of simulated Mars-like atmosphere). Exposure of the different methanogenic strains to increasing concentrations of magnesium perchlorate allowed for the study of their metabolic shutdown in a Mars-relevant perchlorate environment. Survival and metabolic recovery were analyzed by quantitative PCR, gas chromatography, and a new DNA-extraction method from viable cells embedded in S-MRS and P-MRS. All strains survived the two Mars-like desiccating scenarios and recovered to different extents. The permafrost strain SMA-27 showed an increased methanogenic activity by at least 10-fold after deep-freezing conditions. The methanogenic rates of all strains did not decrease significantly after 128 days S-MRS exposure, except for SMA-27, which decreased 10-fold. The activity of strains SMA-17 and SMA-27 decreased after 16 and 60 days P-MRS exposure. Non-permafrost strains showed constant survival and methane production when exposed to both desiccating scenarios. All strains showed unaltered methane production when exposed to the perchlorate concentration reported at the Phoenix landing site (2.4 mM) or even higher concentrations. We conclude that methanogens from (non-)permafrost environments are suitable candidates for potential life in the martian subsurface and therefore are worthy of study after space exposure experiments that approach Mars-like surface conditions.
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Affiliation(s)
- Paloma Serrano
- 1 GFZ, German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section Geomicrobiology, Potsdam, Germany
- 2 AWI, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
| | - Mashal Alawi
- 1 GFZ, German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section Geomicrobiology, Potsdam, Germany
| | - Jean-Pierre de Vera
- 3 German Aerospace Center (DLR), Institute of Planetary Research, Management and Infrastructure, Research Group Astrobiological Laboratories, Berlin, Germany
| | - Dirk Wagner
- 1 GFZ, German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section Geomicrobiology, Potsdam, Germany
- 4 University of Potsdam, Institute of Geosciences, Potsdam, Germany
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21
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Metabolic fingerprints of Serratia liquefaciens under simulated Martian conditions using Biolog GN2 microarrays. Sci Rep 2018; 8:15721. [PMID: 30356072 PMCID: PMC6200771 DOI: 10.1038/s41598-018-33856-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/07/2018] [Indexed: 01/28/2023] Open
Abstract
Microorganisms growing at atmospheric pressures of 0.7 kPa may have a significant impact on the search for life on Mars. Data on their nutrient requirements in a simulated Martian environment are required to ascertain both the potential risk of forward contamination and the potential of past or present habitability of Mars. Serratia liquefaciens can grow at concomitant conditions of low pressure, low temperature, and anoxic atmosphere. Changes in the metabolic fingerprint of S. liquefaciens grown under varying physical conditions including diverse atmospheric pressures (0.7 kPa to 101.3 kPa), temperatures (30 °C or 0 °C), and atmospheric gas compositions (Earth or CO2) were investigated using Biolog GN2 assays. Distinct patterns for each condition were observed. Above 10 kPa S. liquefaciens performed similar to Earth-normal pressure conditions (101.3 kPa) whereas below 10 kPa shifts in metabolic patterns were observed. The differences indicated a physiological alteration in which S. liquefaciens lost its ability to metabolize the majority of the provided carbon sources at 0.7 kPa with a significant decrease in the oxidation of amino acids. By measuring the physiological responses to different carbon sources we were able to identify nutritional constraints that support cellular replication under simulated shallow Mars subsurface conditions.
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Wang A, Sobron P, Kong F, Zheng M, Zhao YYS. Dalangtan Saline Playa in a Hyperarid Region on Tibet Plateau: II. Preservation of Salts with High Hydration Degrees in Subsurface. ASTROBIOLOGY 2018; 18:1254-1276. [PMID: 30152704 DOI: 10.1089/ast.2018.1829] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Based on a field expedition to the Dalangtan (DLT) saline playa located in a hyperarid region (Qaidam Basin) on the Tibet Plateau and follow-up investigations, we report the mineralogy and geochemistry of the salt layers in two vertical stratigraphic cross sections in the DLT playa. Na-, Ca-, Mg-, KCaMg-sulfates; Na-, K-, KMg-chlorides; mixed (K, Mg)-chloride-sulfate; and chlorate and perchlorate were identified in the collected samples. This mineral assemblage represents the last-stage precipitation products from Na-K-Mg-Ca-Cl-SO4 brine and the oxychlorine formation from photochemistry reaction similar to other hyperarid regions on Earth. The spatial distributions of these salts in both stratigraphic cross sections suggest very limited brine volumes during the precipitation episodes in the Holocene era. More importantly, sulfates and chlorides with a high degree of hydrations were found preserved within the subsurface salt-rich layers of DLT saline playa, where the environmental conditions at the surface are controlled by the hyperaridity in the Qaidam Basin on the Tibet Plateau. Our findings suggest a very different temperature and relative humidity environment maintained by the hydrous salts in a subsurface salty layer, where the climatic conditions at surface have very little or no influence. This observation bears some similarities with four observations on Mars, which implies not only a large humidity reservoir in midlatitude and equatorial regions on Mars but also habitability potential that warrants further investigation.
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Affiliation(s)
- Alian Wang
- 1 Department of Earth and Planetary Sciences, McDonnell Center for Space Sciences, Washington University in St. Louis , St. Louis, Missouri
| | - Pablo Sobron
- 2 SETI Institute , Mountain View, California
- 3 Impossible Sensing , St. Louis, Missouri
| | - Fanjing Kong
- 4 MLR Key Laboratory of Saline Lake Environments and Resources, Institute of Mineral Resources , Chinese Academy of Geological Sciences, Beijing, China
| | - Mianping Zheng
- 4 MLR Key Laboratory of Saline Lake Environments and Resources, Institute of Mineral Resources , Chinese Academy of Geological Sciences, Beijing, China
| | - Yu-Yan Sara Zhao
- 5 Institute of Geochemistry , Chinese Academy of Sciences, Guiyang, China
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Blanco Y, Gallardo-Carreño I, Ruiz-Bermejo M, Puente-Sánchez F, Cavalcante-Silva E, Quesada A, Prieto-Ballesteros O, Parro V. Critical Assessment of Analytical Techniques in the Search for Biomarkers on Mars: A Mummified Microbial Mat from Antarctica as a Best-Case Scenario. ASTROBIOLOGY 2017; 17:984-996. [PMID: 29016195 PMCID: PMC5655591 DOI: 10.1089/ast.2016.1467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/20/2017] [Indexed: 05/17/2023]
Abstract
The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing. Key Words: Planetary exploration-Life detection-Microbial mat-Life detector chip-Thermogravimetry-Raman spectroscopy-NIR-DRIFTS. Astrobiology 17, 984-996.
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Affiliation(s)
- Yolanda Blanco
- Department of Molecular Evolution, Centro de Astrobiología (INTA-CSIC), Madrid, Spain
| | | | - Marta Ruiz-Bermejo
- Department of Molecular Evolution, Centro de Astrobiología (INTA-CSIC), Madrid, Spain
| | | | | | - Antonio Quesada
- Department of Molecular Evolution, Centro de Astrobiología (INTA-CSIC), Madrid, Spain
- Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Víctor Parro
- Department of Molecular Evolution, Centro de Astrobiología (INTA-CSIC), Madrid, Spain
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Vago JL, Westall F. Habitability on Early Mars and the Search for Biosignatures with the ExoMars Rover. ASTROBIOLOGY 2017; 17:471-510. [PMID: 31067287 PMCID: PMC5685153 DOI: 10.1089/ast.2016.1533] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 03/05/2017] [Indexed: 05/19/2023]
Abstract
The second ExoMars mission will be launched in 2020 to target an ancient location interpreted to have strong potential for past habitability and for preserving physical and chemical biosignatures (as well as abiotic/prebiotic organics). The mission will deliver a lander with instruments for atmospheric and geophysical investigations and a rover tasked with searching for signs of extinct life. The ExoMars rover will be equipped with a drill to collect material from outcrops and at depth down to 2 m. This subsurface sampling capability will provide the best chance yet to gain access to chemical biosignatures. Using the powerful Pasteur payload instruments, the ExoMars science team will conduct a holistic search for traces of life and seek corroborating geological context information. Key Words: Biosignatures-ExoMars-Landing sites-Mars rover-Search for life. Astrobiology 17, 471-510.
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Messeri L. Extra-terra incognita: Martian maps in the digital age. SOCIAL STUDIES OF SCIENCE 2017; 47:75-94. [PMID: 28195030 DOI: 10.1177/0306312716656820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Science and technology studies (STS) and critical cartography are both asking questions about the ontological fixity of maps and other scientific objects. This paper examines how a group of NASA computer scientists who call themselves The Mapmakers conceptualizes and creates maps in service of different commitments. The maps under construction are those of alien Mars, produced through partnerships that NASA has established with Google and Microsoft. With the goal of bringing an experience of Mars to as many people as possible, these maps influence how we imagine our neighbouring planet. This paper analyzes two attributes of the map, evident in both its representation and the attending cartographic practices: a sense of Mars as dynamic and a desire for a democratic experience of Mars in which up-to-date Mars data can be intuitively accessed not only by scientists but by lay users as well. Whereas a democratic Mars promises users the ability to decide how to interact with the map and understand Mars, dynamic Mars imposes a more singular sense of Mars as a target of continued robotic and maybe even human exploration. Because maps of Mars have a different (and arguably less complex) set of social and political commitments than those of Earth, they help us see how different goals contradict and complement each other in matters of exploration and state-craft relevant both to other worlds and our own.
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Affiliation(s)
- Lisa Messeri
- Department of Engineering and Society, University of Virginia, Charlottesville, VA, USA
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Ruecker A, Schröder C, Byrne J, Weigold P, Behrens S, Kappler A. Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars. ASTROBIOLOGY 2016; 16:525-538. [PMID: 27258848 DOI: 10.1089/ast.2015.1429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1%), the sediments' pH values differ and range from 3.8 to 4.8 in Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments. KEY WORDS Western Australia-Salt lakes-Jarosite-Hematite-Pyrite-Mars analogue. Astrobiology 16, 525-538.
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Affiliation(s)
- A Ruecker
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - C Schröder
- 2 Biological and Environmental Sciences, School of Natural Sciences, University of Stirling , Stirling, Scotland, UK
| | - J Byrne
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - P Weigold
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - S Behrens
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - A Kappler
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
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Cockell CS, Bush T, Bryce C, Direito S, Fox-Powell M, Harrison JP, Lammer H, Landenmark H, Martin-Torres J, Nicholson N, Noack L, O'Malley-James J, Payler SJ, Rushby A, Samuels T, Schwendner P, Wadsworth J, Zorzano MP. Habitability: A Review. ASTROBIOLOGY 2016; 16:89-117. [PMID: 26741054 DOI: 10.1089/ast.2015.1295] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Habitability is a widely used word in the geoscience, planetary science, and astrobiology literature, but what does it mean? In this review on habitability, we define it as the ability of an environment to support the activity of at least one known organism. We adopt a binary definition of "habitability" and a "habitable environment." An environment either can or cannot sustain a given organism. However, environments such as entire planets might be capable of supporting more or less species diversity or biomass compared with that of Earth. A clarity in understanding habitability can be obtained by defining instantaneous habitability as the conditions at any given time in a given environment required to sustain the activity of at least one known organism, and continuous planetary habitability as the capacity of a planetary body to sustain habitable conditions on some areas of its surface or within its interior over geological timescales. We also distinguish between surface liquid water worlds (such as Earth) that can sustain liquid water on their surfaces and interior liquid water worlds, such as icy moons and terrestrial-type rocky planets with liquid water only in their interiors. This distinction is important since, while the former can potentially sustain habitable conditions for oxygenic photosynthesis that leads to the rise of atmospheric oxygen and potentially complex multicellularity and intelligence over geological timescales, the latter are unlikely to. Habitable environments do not need to contain life. Although the decoupling of habitability and the presence of life may be rare on Earth, it may be important for understanding the habitability of other planetary bodies.
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Affiliation(s)
- C S Cockell
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - T Bush
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - C Bryce
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - S Direito
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - M Fox-Powell
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - J P Harrison
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - H Lammer
- 2 Austrian Academy of Sciences, Space Research Institute , Graz, Austria
| | - H Landenmark
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - J Martin-Torres
- 3 Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology , Kiruna, Sweden; and Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Armilla, Granada, Spain
| | - N Nicholson
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - L Noack
- 4 Department of Reference Systems and Planetology, Royal Observatory of Belgium , Brussels, Belgium
| | - J O'Malley-James
- 5 School of Physics and Astronomy, University of St Andrews , St Andrews, UK; now at the Carl Sagan Institute, Cornell University, Ithaca, NY, USA
| | - S J Payler
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - A Rushby
- 6 Centre for Ocean and Atmospheric Science (COAS), School of Environmental Sciences, University of East Anglia , Norwich, UK
| | - T Samuels
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - P Schwendner
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - J Wadsworth
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - M P Zorzano
- 3 Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology , Kiruna, Sweden; and Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Armilla, Granada, Spain
- 7 Centro de Astrobiología (CSIC-INTA) , Torrejón de Ardoz, Madrid, Spain
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Westall F, Foucher F, Bost N, Bertrand M, Loizeau D, Vago JL, Kminek G, Gaboyer F, Campbell KA, Bréhéret JG, Gautret P, Cockell CS. Biosignatures on Mars: What, Where, and How? Implications for the Search for Martian Life. ASTROBIOLOGY 2015; 15:998-1029. [PMID: 26575218 PMCID: PMC4653824 DOI: 10.1089/ast.2015.1374] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 10/13/2015] [Indexed: 05/18/2023]
Abstract
UNLABELLED The search for traces of life is one of the principal objectives of Mars exploration. Central to this objective is the concept of habitability, the set of conditions that allows the appearance of life and successful establishment of microorganisms in any one location. While environmental conditions may have been conducive to the appearance of life early in martian history, habitable conditions were always heterogeneous on a spatial scale and in a geological time frame. This "punctuated" scenario of habitability would have had important consequences for the evolution of martian life, as well as for the presence and preservation of traces of life at a specific landing site. We hypothesize that, given the lack of long-term, continuous habitability, if martian life developed, it was (and may still be) chemotrophic and anaerobic. Obtaining nutrition from the same kinds of sources as early terrestrial chemotrophic life and living in the same kinds of environments, the fossilized traces of the latter serve as useful proxies for understanding the potential distribution of martian chemotrophs and their fossilized traces. Thus, comparison with analog, anaerobic, volcanic terrestrial environments (Early Archean >3.5-3.33 Ga) shows that the fossil remains of chemotrophs in such environments were common, although sparsely distributed, except in the vicinity of hydrothermal activity where nutrients were readily available. Moreover, the traces of these kinds of microorganisms can be well preserved, provided that they are rapidly mineralized and that the sediments in which they occur are rapidly cemented. We evaluate the biogenicity of these signatures by comparing them to possible abiotic features. Finally, we discuss the implications of different scenarios for life on Mars for detection by in situ exploration, ranging from its non-appearance, through preserved traces of life, to the presence of living microorganisms. KEY WORDS Mars-Early Earth-Anaerobic chemotrophs-Biosignatures-Astrobiology missions to Mars.
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Affiliation(s)
- Frances Westall
- CNRS-OSUC-Centre de Biophysique Moléculaire, CS80054, Orléans, France
| | - Frédéric Foucher
- CNRS-OSUC-Centre de Biophysique Moléculaire, CS80054, Orléans, France
| | - Nicolas Bost
- CNRS-Conditions Extrêmes et Matériaux: Haute Température et Irradiation, CS90055, Orléans, France
| | - Marylène Bertrand
- CNRS-OSUC-Centre de Biophysique Moléculaire, CS80054, Orléans, France
| | | | | | | | - Frédéric Gaboyer
- CNRS-OSUC-Centre de Biophysique Moléculaire, CS80054, Orléans, France
| | | | - Jean-Gabriel Bréhéret
- GéoHydrosytèmes Continentaux, Faculté des Sciences et Techniques, Université François-Rabelais de Tours, Tours, France
| | - Pascale Gautret
- CNRS-OSUC-Institut des Sciences de la Terre d'Orléans, Orléans, France
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Schuerger AC, Lee P. Microbial Ecology of a Crewed Rover Traverse in the Arctic: Low Microbial Dispersal and Implications for Planetary Protection on Human Mars Missions. ASTROBIOLOGY 2015; 15:478-91. [PMID: 26060984 PMCID: PMC4490634 DOI: 10.1089/ast.2015.1289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/27/2015] [Indexed: 05/13/2023]
Abstract
Between April 2009 and July 2011, the NASA Haughton-Mars Project (HMP) led the Northwest Passage Drive Expedition (NWPDX), a multi-staged long-distance crewed rover traverse along the Northwest Passage in the Arctic. In April 2009, the HMP Okarian rover was driven 496 km over sea ice along the Northwest Passage, from Kugluktuk to Cambridge Bay, Nunavut, Canada. During the traverse, crew members collected samples from within the rover and from undisturbed snow-covered surfaces around the rover at three locations. The rover samples and snow samples were stored at subzero conditions (-20°C to -1°C) until processed for microbial diversity in labs at the NASA Kennedy Space Center, Florida. The objective was to determine the extent of microbial dispersal away from the rover and onto undisturbed snow. Interior surfaces of the rover were found to be associated with a wide range of bacteria (69 unique taxa) and fungi (16 unique taxa). In contrast, snow samples from the upwind, downwind, uptrack, and downtrack sample sites exterior to the rover were negative for both bacteria and fungi except for two colony-forming units (cfus) recovered from one downwind (1 cfu; site A4) and one uptrack (1 cfu; site B6) sample location. The fungus, Aspergillus fumigatus (GenBank JX517279), and closely related bacteria in the genus Brevibacillus were recovered from both snow (B. agri, GenBank JX517278) and interior rover surfaces. However, it is unknown whether the microorganisms were deposited onto snow surfaces at the time of sample collection (i.e., from the clothing or skin of the human operator) or via airborne dispersal from the rover during the 12-18 h layovers at the sites prior to collection. Results support the conclusion that a crewed rover traveling over previously undisturbed terrain may not significantly contaminate the local terrain via airborne dispersal of propagules from the vehicle.
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Affiliation(s)
- Andrew C. Schuerger
- University of Florida, Space Life Sciences Lab, Kennedy Space Center, Florida
| | - Pascal Lee
- Mars Institute, Moffett Field, California
- SETI Institute, Moffett Field, California
- NASA Ames Research Center, Moffett Field, California
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Martin D, Cockell CS. PELS (Planetary Environmental Liquid Simulator): a new type of simulation facility to study extraterrestrial aqueous environments. ASTROBIOLOGY 2015; 15:111-118. [PMID: 25651097 DOI: 10.1089/ast.2014.1240] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Investigations of other planetary bodies, including Mars and icy moons such as Enceladus and Europa, show that they may have hosted aqueous environments in the past and may do so even today. Therefore, a major challenge in astrobiology is to build facilities that will allow us to study the geochemistry and habitability of these extraterrestrial environments. Here, we describe a simulation facility (PELS: Planetary Environmental Liquid Simulator) with the capability for liquid input and output that allows for the study of such environments. The facility, containing six separate sample vessels, allows for statistical replication of samples. Control of pressure, gas composition, UV irradiation conditions, and temperature allows for the precise replication of aqueous conditions, including subzero brines under martian atmospheric conditions. A sample acquisition system allows for the collection of both liquid and solid samples from within the chamber without breaking the atmospheric conditions, enabling detailed studies of the geochemical evolution and habitability of past and present extraterrestrial environments. The facility we describe represents a new frontier in planetary simulation-continuous flow-through simulation of extraterrestrial aqueous environments.
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Affiliation(s)
- Derek Martin
- School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
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31
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Shelor CP, Dasgupta PK, Aubrey A, Davila AF, Lee MC, McKay CP, Liu Y, Noell AC. What can in situ ion chromatography offer for Mars exploration? ASTROBIOLOGY 2014; 14:577-588. [PMID: 24963874 DOI: 10.1089/ast.2013.1131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The successes of the Mars exploration program have led to our unprecedented knowledge of the geological, mineralogical, and elemental composition of the martian surface. To date, however, only one mission, the Phoenix lander, has specifically set out to determine the soluble chemistry of the martian surface. The surprising results, including the detection of perchlorate, demonstrated both the importance of performing soluble ion measurements and the need for improved instrumentation to unambiguously identify all the species present. Ion chromatography (IC) is the state-of-the-art technique for soluble ion analysis on Earth and would therefore be the ideal instrument to send to Mars. A flight IC system must necessarily be small, lightweight, low-power, and have low eluent consumption. We demonstrate here a breadboard system that addresses these issues by using capillary IC at low flow rates with an optimized eluent generator and suppressor. A mix of 12 ions known or plausible for the martian soil, including 4 (oxy)chlorine species, has been separated at flow rates ranging from 1 to 10 μL/min, requiring as little as 200 psi at 1.0 μL/min. This allowed the use of pneumatic displacement pumping from a pressurized aluminum eluent reservoir and the elimination of the high-pressure pump entirely (the single heaviest and most energy-intensive component). All ions could be separated and detected effectively from 0.5 to 100 μM, even when millimolar concentrations of perchlorate were present in the same mixtures.
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Affiliation(s)
- C Phillip Shelor
- 1 Department of Chemistry and Biochemistry, The University of Texas at Arlington , Arlington, Texas
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32
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Zakharova K, Marzban G, de Vera JP, Lorek A, Sterflinger K. Protein patterns of black fungi under simulated Mars-like conditions. Sci Rep 2014; 4:5114. [PMID: 24870977 PMCID: PMC4037706 DOI: 10.1038/srep05114] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 05/14/2014] [Indexed: 01/30/2023] Open
Abstract
Two species of microcolonial fungi – Cryomyces antarcticus and Knufia perforans - and a species of black yeasts–Exophiala jeanselmei - were exposed to thermo-physical Mars-like conditions in the simulation chamber of the German Aerospace Center. In this study the alterations at the protein expression level from various fungi species under Mars-like conditions were analyzed for the first time using 2D gel electrophoresis. Despite of the expectations, the fungi did not express any additional proteins under Mars simulation that could be interpreted as stress induced HSPs. However, up-regulation of some proteins and significant decreasing of protein number were detected within the first 24 hours of the treatment. After 4 and 7 days of the experiment protein spot number was increased again and the protein patterns resemble the protein patterns of biomass from normal conditions. It indicates the recovery of the metabolic activity under Martian environmental conditions after one week of exposure.
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Affiliation(s)
- Kristina Zakharova
- University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 18, A - 1190 Vienna, Austria
| | - Gorji Marzban
- University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 18, A - 1190 Vienna, Austria
| | - Jean-Pierre de Vera
- German Aerospace Center, Institute of Planetary Research, Rutherfordstrasse 2, D-12489 Berlin, Germany
| | - Andreas Lorek
- German Aerospace Center, Institute of Planetary Research, Rutherfordstrasse 2, D-12489 Berlin, Germany
| | - Katja Sterflinger
- University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 18, A - 1190 Vienna, Austria
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33
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Cockell CS. Trajectories of martian habitability. ASTROBIOLOGY 2014; 14:182-203. [PMID: 24506485 PMCID: PMC3929387 DOI: 10.1089/ast.2013.1106] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/29/2013] [Indexed: 05/21/2023]
Abstract
Beginning from two plausible starting points-an uninhabited or inhabited Mars-this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
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Heldmann JL, Schurmeier L, McKay C, Davila A, Stoker C, Marinova M, Wilhelm MB. Midlatitude ice-rich ground on mars as a target in the search for evidence of life and for in situ resource utilization on human missions. ASTROBIOLOGY 2014; 14:102-118. [PMID: 24506507 DOI: 10.1089/ast.2013.1103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Midlatitude ground ice on Mars is of significant scientific interest for understanding the history and evolution of ice stability on Mars and is relevant for human exploration as a possible in situ resource. For both science and exploration, assessing the astrobiological potential of the ice is important in terms of (1) understanding the potential for life on Mars and (2) evaluating the presence of possible biohazards in advance of human exploration. In the present study, we review the evidence for midlatitude ground ice on Mars, discuss the possible explanations for its occurrence, and assess its potential habitability. During the course of study, we systematically analyzed remote-sensing data sets to determine whether a viable landing site exists in the northern midlatitudes to enable a robotic mission that conducts in situ characterization and searches for evidence of life in the ice. We classified each site according to (1) presence of polygons as a proxy for subsurface ice, (2) presence and abundance of rough topographic obstacles (e.g., large cracks, cliffs, uneven topography), (3) rock density, (4) presence and abundance of large boulders, and (5) presence of craters. We found that a suitable landing site exists within Amazonis Planitia near ground ice that was recently excavated by a meteorite impact.
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Affiliation(s)
- J L Heldmann
- 1 NASA Ames Research Center , Division of Space Sciences and Astrobiology, Moffett Field, California
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Goordial J, Lamarche-Gagnon G, Lay CY, Whyte L. Left Out in the Cold: Life in Cryoenvironments. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/978-94-007-6488-0_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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Davé A, Thompson SJ, McKay CP, Stoker CR, Zacny K, Paulsen G, Mellerowicz B, Glass BJ, Willson D, Bonaccorsi R, Rask J. The sample handling system for the Mars Icebreaker Life mission: from dirt to data. ASTROBIOLOGY 2013; 13:354-369. [PMID: 23577818 DOI: 10.1089/ast.2012.0911] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The Mars Icebreaker Life mission will search for subsurface life on Mars. It consists of three payload elements: a drill to retrieve soil samples from approximately 1 m below the surface, a robotic sample handling system to deliver the sample from the drill to the instruments, and the instruments themselves. This paper will discuss the robotic sample handling system. Collecting samples from ice-rich soils on Mars in search of life presents two challenges: protection of that icy soil--considered a "special region" with respect to planetary protection--from contamination from Earth, and delivery of the icy, sticky soil to spacecraft instruments. We present a sampling device that meets these challenges. We built a prototype system and tested it at martian pressure, drilling into ice-cemented soil, collecting cuttings, and transferring them to the inlet port of the SOLID2 life-detection instrument. The tests successfully demonstrated that the Icebreaker drill, sample handling system, and life-detection instrument can collectively operate in these conditions and produce science data that can be delivered via telemetry--from dirt to data. Our results also demonstrate the feasibility of using an air gap to prevent forward contamination. We define a set of six analog soils for testing over a range of soil cohesion, from loose sand to basalt soil, with angles of repose of 27° and 39°, respectively. Particle size is a key determinant of jamming of mechanical parts by soil particles. Jamming occurs when the clearance between moving parts is equal in size to the most common particle size or equal to three of these particles together. Three particles acting together tend to form bridges and lead to clogging. Our experiments show that rotary-hammer action of the Icebreaker drill influences the particle size, typically reducing particle size by ≈ 100 μm.
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Affiliation(s)
- Arwen Davé
- NASA Ames Research Center, Moffett Field, California 94035, USA.
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McKay CP, Stoker CR, Glass BJ, Davé AI, Davila AF, Heldmann JL, Marinova MM, Fairen AG, Quinn RC, Zacny KA, Paulsen G, Smith PH, Parro V, Andersen DT, Hecht MH, Lacelle D, Pollard WH. The Icebreaker Life Mission to Mars: a search for biomolecular evidence for life. ASTROBIOLOGY 2013; 13:334-53. [PMID: 23560417 DOI: 10.1089/ast.2012.0878] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The search for evidence of life on Mars is the primary motivation for the exploration of that planet. The results from previous missions, and the Phoenix mission in particular, indicate that the ice-cemented ground in the north polar plains is likely to be the most recently habitable place that is currently known on Mars. The near-surface ice likely provided adequate water activity during periods of high obliquity, ≈ 5 Myr ago. Carbon dioxide and nitrogen are present in the atmosphere, and nitrates may be present in the soil. Perchlorate in the soil together with iron in basaltic rock provides a possible energy source for life. Furthermore, the presence of organics must once again be considered, as the results of the Viking GCMS are now suspect given the discovery of the thermally reactive perchlorate. Ground ice may provide a way to preserve organic molecules for extended periods of time, especially organic biomarkers. The Mars Icebreaker Life mission focuses on the following science goals: (1) Search for specific biomolecules that would be conclusive evidence of life. (2) Perform a general search for organic molecules in the ground ice. (3) Determine the processes of ground ice formation and the role of liquid water. (4) Understand the mechanical properties of the martian polar ice-cemented soil. (5) Assess the recent habitability of the environment with respect to required elements to support life, energy sources, and possible toxic elements. (6) Compare the elemental composition of the northern plains with midlatitude sites. The Icebreaker Life payload has been designed around the Phoenix spacecraft and is targeted to a site near the Phoenix landing site. However, the Icebreaker payload could be supported on other Mars landing systems. Preliminary studies of the SpaceX Dragon lander show that it could support the Icebreaker payload for a landing either at the Phoenix site or at midlatitudes. Duplicate samples could be cached as a target for possible return by a Mars Sample Return mission. If the samples were shown to contain organic biomarkers, interest in returning them to Earth would be high.
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Schuerger AC, Ulrich R, Berry BJ, Nicholson WL. Growth of Serratia liquefaciens under 7 mbar, 0°C, and CO2-enriched anoxic atmospheres. ASTROBIOLOGY 2013; 13:115-31. [PMID: 23289858 PMCID: PMC3582281 DOI: 10.1089/ast.2011.0811] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 11/28/2012] [Indexed: 05/21/2023]
Abstract
Twenty-six strains of 22 bacterial species were tested for growth on trypticase soy agar (TSA) or sea-salt agar (SSA) under hypobaric, psychrophilic, and anoxic conditions applied singly or in combination. As each factor was added to multi-parameter assays, the interactive stresses decreased the numbers of strains capable of growth and, in general, reduced the vigor of the strains observed to grow. Only Serratia liquefaciens strain ATCC 27592 exhibited growth at 7 mbar, 0°C, and CO2-enriched anoxic atmospheres. To discriminate between the effects of desiccation and hypobaria, vegetative cells of Bacillus subtilis strain 168 and Escherichia coli strain K12 were grown on TSA surfaces and simultaneously in liquid Luria-Bertani (LB) broth media. Inhibition of growth under hypobaria for 168 and K12 decreased in similar ways for both TSA and LB assays as pressures were reduced from 100 to 25 mbar. Results for 168 and K12 on TSA and LB are interpreted to indicate a direct low-pressure effect on microbial growth with both species and do not support the hypothesis that desiccation alone on TSA was the cause of reduced growth at low pressures. The growth of S. liquefaciens at 7 mbar, 0°C, and CO2-enriched anoxic atmospheres was surprising since S. liquefaciens is ecologically a generalist that occurs in terrestrial plant, fish, animal, and food niches. In contrast, two extremophiles tested in the assays, Deinococcus radiodurans strain R1 and Psychrobacter cryohalolentis strain K5, failed to grow under hypobaric (25 mbar; R1 only), psychrophilic (0°C; R1 only), or anoxic (< 0.1% ppO2; both species) conditions.
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Affiliation(s)
- Andrew C Schuerger
- Department of Plant Pathology, University of Florida , Space Life Sciences Lab, Kennedy Space Center, Florida 32899, USA.
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Simulation and Measurement of Extraterrestrial Conditions for Experiments on Habitability with Respect to Mars. HABITABILITY OF OTHER PLANETS AND SATELLITES 2013. [DOI: 10.1007/978-94-007-6546-7_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Rix CS, Sims MR, Cullen DC. Immunological detection of small organic molecules in the presence of perchlorates: relevance to the life marker chip and life detection on Mars. ASTROBIOLOGY 2011; 11:839-846. [PMID: 22011057 DOI: 10.1089/ast.2011.0662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The proposed ExoMars mission, due to launch in 2018, aims to look for evidence of extant and extinct life in martian rocks and regolith. Previous attempts to detect organic molecules of biological or abiotic origin on Mars have been unsuccessful, which may be attributable to destruction of these molecules by perchlorate salts during pyrolysis sample extraction techniques. Organic molecules can also be extracted and measured with solvent-based systems. The ExoMars payload includes the Life Marker Chip (LMC) instrument, capable of detecting biomarker molecules of extant and extinct Earth-like life in liquid extracts of martian samples with an antibody microarray assay. The aim of the work reported here was to investigate whether the presence of perchlorate salts, at levels similar to those at the NASA Phoenix landing site, would compromise the LMC extraction and detection method. To test this, we implemented an LMC-representative sample extraction process with an LMC-representative antibody assay and used these to extract and analyze a model sample that consisted of a Mars analog sample matrix (JSC Mars-1) spiked with a representative organic molecular target (pyrene, an example of abiotic meteoritic infall targets) in the presence of perchlorate salts. We found no significant change in immunoassay function when using pyrene standards with added perchlorate salts. When model samples spiked with perchlorate salts were subjected to an LMC-representative liquid extraction, immunoassays functioned in a liquid extract and detected extracted pyrene. For the same model sample matrix without perchlorate salts, we observed anomalous assay signals that coincided with yellow coloration of the extracts. This unexpected observation is being studied further. This initial study indicates that the presence of perchlorate salts, at levels similar to those detected at the NASA Phoenix landing site, is unlikely to prevent the LMC from extracting and detecting organic molecules from martian samples.
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McEwen AS, Ojha L, Dundas CM, Mattson SS, Byrne S, Wray JJ, Cull SC, Murchie SL, Thomas N, Gulick VC. Seasonal flows on warm Martian slopes. Science 2011; 333:740-3. [PMID: 21817049 DOI: 10.1126/science.1204816] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Water probably flowed across ancient Mars, but whether it ever exists as a liquid on the surface today remains debatable. Recurring slope lineae (RSL) are narrow (0.5 to 5 meters), relatively dark markings on steep (25° to 40°) slopes; repeat images from the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment show them to appear and incrementally grow during warm seasons and fade in cold seasons. They extend downslope from bedrock outcrops, often associated with small channels, and hundreds of them form in some rare locations. RSL appear and lengthen in the late southern spring and summer from 48°S to 32°S latitudes favoring equator-facing slopes, which are times and places with peak surface temperatures from ~250 to 300 kelvin. Liquid brines near the surface might explain this activity, but the exact mechanism and source of water are not understood.
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Affiliation(s)
- Alfred S McEwen
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA.
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Cockell CS. Vacant habitats in the Universe. Trends Ecol Evol 2011; 26:73-80. [DOI: 10.1016/j.tree.2010.11.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 11/13/2010] [Accepted: 11/15/2010] [Indexed: 12/14/2022]
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Fairén AG, Davila AF, Lim D, Bramall N, Bonaccorsi R, Zavaleta J, Uceda ER, Stoker C, Wierzchos J, Dohm JM, Amils R, Andersen D, McKay CP. Astrobiology through the ages of Mars: the study of terrestrial analogues to understand the habitability of Mars. ASTROBIOLOGY 2010; 10:821-843. [PMID: 21087162 DOI: 10.1089/ast.2009.0440] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Mars has undergone three main climatic stages throughout its geological history, beginning with a water-rich epoch, followed by a cold and semi-arid era, and transitioning into present-day arid and very cold desert conditions. These global climatic eras also represent three different stages of planetary habitability: an early, potentially habitable stage when the basic requisites for life as we know it were present (liquid water and energy); an intermediate extreme stage, when liquid solutions became scarce or very challenging for life; and the most recent stage during which conditions on the surface have been largely uninhabitable, except perhaps in some isolated niches. Our understanding of the evolution of Mars is now sufficient to assign specific terrestrial environments to each of these periods. Through the study of Mars terrestrial analogues, we have assessed and constrained the habitability conditions for each of these stages, the geochemistry of the surface, and the likelihood for the preservation of organic and inorganic biosignatures. The study of these analog environments provides important information to better understand past and current mission results as well as to support the design and selection of instruments and the planning for future exploratory missions to Mars.
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