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Kminek G, Benardini JN, Brenker FE, Brooks T, Burton AS, Dhaniyala S, Dworkin JP, Fortman JL, Glamoclija M, Grady MM, Graham HV, Haruyama J, Kieft TL, Koopmans M, McCubbin FM, Meyer MA, Mustin C, Onstott TC, Pearce N, Pratt LM, Sephton MA, Siljeström S, Sugahara H, Suzuki S, Suzuki Y, van Zuilen M, Viso M. COSPAR Sample Safety Assessment Framework (SSAF). ASTROBIOLOGY 2022; 22:S186-S216. [PMID: 35653292 DOI: 10.1089/ast.2022.0017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The Committee on Space Research (COSPAR) Sample Safety Assessment Framework (SSAF) has been developed by a COSPAR appointed Working Group. The objective of the sample safety assessment would be to evaluate whether samples returned from Mars could be harmful for Earth's systems (e.g., environment, biosphere, geochemical cycles). During the Working Group's deliberations, it became clear that a comprehensive assessment to predict the effects of introducing life in new environments or ecologies is difficult and practically impossible, even for terrestrial life and certainly more so for unknown extraterrestrial life. To manage expectations, the scope of the SSAF was adjusted to evaluate only whether the presence of martian life can be excluded in samples returned from Mars. If the presence of martian life cannot be excluded, a Hold & Critical Review must be established to evaluate the risk management measures and decide on the next steps. The SSAF starts from a positive hypothesis (there is martian life in the samples), which is complementary to the null-hypothesis (there is no martian life in the samples) typically used for science. Testing the positive hypothesis includes four elements: (1) Bayesian statistics, (2) subsampling strategy, (3) test sequence, and (4) decision criteria. The test sequence capability covers self-replicating and non-self-replicating biology and biologically active molecules. Most of the investigations associated with the SSAF would need to be carried out within biological containment. The SSAF is described in sufficient detail to support planning activities for a Sample Receiving Facility (SRF) and for preparing science announcements, while at the same time acknowledging that further work is required before a detailed Sample Safety Assessment Protocol (SSAP) can be developed. The three major open issues to be addressed to optimize and implement the SSAF are (1) setting a value for the level of assurance to effectively exclude the presence of martian life in the samples, (2) carrying out an analogue test program, and (3) acquiring relevant contamination knowledge from all Mars Sample Return (MSR) flight and ground elements. Although the SSAF was developed specifically for assessing samples from Mars in the context of the currently planned NASA-ESA MSR Campaign, this framework and the basic safety approach are applicable to any other Mars sample return mission concept, with minor adjustments in the execution part related to the specific nature of the samples to be returned. The SSAF is also considered a sound basis for other COSPAR Planetary Protection Category V, restricted Earth return missions beyond Mars. It is anticipated that the SSAF will be subject to future review by the various MSR stakeholders.
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Affiliation(s)
- Gerhard Kminek
- European Space Agency, Mars Exploration Group, Noordwijk, The Netherlands
| | - James N Benardini
- NASA Headquarters, Office of Planetary Protection, Washington, DC, USA
| | - Frank E Brenker
- Goethe University, Department of Geoscience, Frankfurt, Germany
| | - Timothy Brooks
- UK Health Security Agency, Rare & Imported Pathogens Laboratory, Salisbury, UK
| | - Aaron S Burton
- NASA Johnson Space Center, Astromaterials Research and Exploration Science Division, Houston, Texas, USA
| | - Suresh Dhaniyala
- Clarkson University, Department of Mechanical and Aeronautical Engineering, Potsdam, New York, USA
| | - Jason P Dworkin
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, Maryland, USA
| | - Jeffrey L Fortman
- Security Programs, Engineering Biology Research Consortium, Emeryville, USA
| | - Mihaela Glamoclija
- Rutgers University, Department of Earth and Environmental Sciences, Newark, New Jersey, USA
| | - Monica M Grady
- The Open University, Faculty of Science, Technology, Engineering & Mathematics, Milton Keynes, UK
| | - Heather V Graham
- NASA Goddard Space Flight Center, Astrochemistry Laboratory, Greenbelt, Maryland, USA
| | - Junichi Haruyama
- Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science (ISAS), Chofu, Tokyo, Japan
| | - Thomas L Kieft
- New Mexico Institute of Mining and Technology, Biology Department, Socorro, New Mexico, USA
| | - Marion Koopmans
- Erasmus University Medical Centre, Department of Viroscience, Rotterdam, The Netherlands
| | - Francis M McCubbin
- NASA Johnson Space Center, Astromaterials Research and Exploration Science Division, Houston, Texas, USA
| | - Michael A Meyer
- NASA Headquarters, Planetary Science Division, Washington, DC, USA
| | | | - Tullis C Onstott
- Princeton University, Department of Geosciences, Princeton, New Jersey, USA
| | - Neil Pearce
- London School of Hygiene & Tropical Medicine, Department of Medical Statistics, London, UK
| | - Lisa M Pratt
- Indiana University Bloomington, Earth and Atmospheric Sciences, Emeritus, Bloomington, Indiana, USA
| | - Mark A Sephton
- Imperial College London, Department of Earth Science & Engineering, London, UK
| | - Sandra Siljeström
- RISE, Research Institutes of Sweden, Department of Methodology, Textiles and Medical Technology, Stockholm, Sweden
| | - Haruna Sugahara
- Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science, Sagamihara Kanagawa, Japan
| | - Shino Suzuki
- Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science, Sagamihara Kanagawa, Japan
| | - Yohey Suzuki
- University of Tokyo, Graduate School of Science, Tokyo, Japan
| | - Mark van Zuilen
- Université de Paris, Institut de Physique du Globe de Paris, Paris, France
- European Institute for Marine Studies (IUEM), CNRS-UMR6538 Laboratoire Geo-Ocean, Plouzané, France
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Getenet M, Rieder J, Kellermeier M, Kunz W, Manuel García-Ruiz J. Tubular Structures of Calcium Carbonate: Formation, Characterization, and Implications in Natural Mineral Environments. Chemistry 2021; 27:16135-16144. [PMID: 34590745 DOI: 10.1002/chem.202101417] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Indexed: 01/16/2023]
Abstract
Chemical gardens are self-assembled tubular precipitates formed by a combination of osmosis, buoyancy, and chemical reaction, and thought to be capable of catalyzing prebiotic condensation reactions. In many cases, the tube wall is a bilayer structure with the properties of a diaphragm and/or a membrane. The interest in silica gardens as microreactors for materials science has increased over the past decade because of their ability to create long-lasting electrochemical potential. In this study, we have grown single macroscopic tubes based on calcium carbonate and monitored their time-dependent behavior by in situ measurements of pH, ionic concentrations inside and outside the tubular membranes, and electrochemical potential differences. Furthermore, we have characterized the composition and structure of the tubular membranes by using ex situ X-ray diffraction, infrared and Raman spectroscopy, as well as scanning electron microscopy. Based on the collected data, we propose a physicochemical mechanism for the formation and ripening of these peculiar CaCO3 structures and compare the results to those of other chemical garden systems. We find that the wall of the macroscopic calcium carbonate tubes is a bilayer of texturally distinct but compositionally similar calcite showing high crystallinity. The resulting high density of the material prevents macroscopic calcium carbonate gardens from developing significant electrochemical potential differences. In the light of these observations, possible implications in materials science and prebiotic (geo)chemistry are discussed.
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Affiliation(s)
- Melese Getenet
- Laboratorio de Estudios Cristalográficos, Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Avenida de las Palmeras 4, Armilla, 18100, Granada, Spain
| | - Julian Rieder
- Institute of Physical and Theoretical Chemistry, University of Regensburg, 93053, Regensburg, Germany
| | - Matthias Kellermeier
- Material Physics, BASF SE, RAA/OS-B007, Carl-Bosch-Strasse 38, 67056, Ludwigshafen am Rhein, Germany
| | - Werner Kunz
- Institute of Physical and Theoretical Chemistry, University of Regensburg, 93053, Regensburg, Germany
| | - Juan Manuel García-Ruiz
- Laboratorio de Estudios Cristalográficos, Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Avenida de las Palmeras 4, Armilla, 18100, Granada, Spain
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Russell MJ. The "Water Problem"( sic), the Illusory Pond and Life's Submarine Emergence-A Review. Life (Basel) 2021; 11:429. [PMID: 34068713 PMCID: PMC8151828 DOI: 10.3390/life11050429] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 04/30/2021] [Accepted: 05/01/2021] [Indexed: 01/10/2023] Open
Abstract
The assumption that there was a "water problem" at the emergence of life-that the Hadean Ocean was simply too wet and salty for life to have emerged in it-is here subjected to geological and experimental reality checks. The "warm little pond" that would take the place of the submarine alkaline vent theory (AVT), as recently extolled in the journal Nature, flies in the face of decades of geological, microbiological and evolutionary research and reasoning. To the present author, the evidence refuting the warm little pond scheme is overwhelming given the facts that (i) the early Earth was a water world, (ii) its all-enveloping ocean was never less than 4 km deep, (iii) there were no figurative "Icelands" or "Hawaiis", nor even an "Ontong Java" then because (iv) the solidifying magma ocean beneath was still too mushy to support such salient loadings on the oceanic crust. In place of the supposed warm little pond, we offer a well-protected mineral mound precipitated at a submarine alkaline vent as life's womb: in place of lipid membranes, we suggest peptides; we replace poisonous cyanide with ammonium and hydrazine; instead of deleterious radiation we have the appropriate life-giving redox and pH disequilibria; and in place of messy chemistry we offer the potential for life's emergence from the simplest of geochemically available molecules and ions focused at a submarine alkaline vent in the Hadean-specifically within the nano-confined flexible and redox active interlayer walls of the mixed-valent double layer oxyhydroxide mineral, fougerite/green rust comprising much of that mound.
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Affiliation(s)
- Michael J Russell
- Dipartimento di Chimica, Università degli Studi di Torino, via P. Giuria 7, 10125 Turin, Italy
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