1,296 results match your criteria Astrobiology[Journal]


Mineralogy, Structure, and Habitability of Carbon-Enriched Rocky Exoplanets: A Laboratory Approach.

Astrobiology 2019 Apr 17. Epub 2019 Apr 17.

2 Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.

Carbon-enriched rocky exoplanets have been proposed to occur around dwarf stars as well as binary stars, white dwarfs, and pulsars. However, the mineralogical make up of such planets is poorly constrained. We performed high-pressure high-temperature laboratory experiments ( = 1-2 GPa,  = 1523-1823 K) on chemical mixtures representative of C-enriched rocky exoplanets based on calculations of protoplanetary disk compositions. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1930DOI Listing

Searching for Atmospheric Bioindicators in Planets around the Two Nearby Stars, Proxima Centauri and Epsilon Eridani-Test Cases for Retrieval of Atmospheric Gases with Infrared Spectroscopy.

Astrobiology 2019 Apr 13. Epub 2019 Apr 13.

7 Department of Earth System Science, Tsinghua University, Beijing, China.

We tested the ability of thermal infrared spectroscopy to retrieve assumed atmospheric compositions for different types of planets orbiting Proxima Centauri and Epsilon Eridani. Six cases are considered, covering a range of atmospheric compositions and some diversity in the bulk composition (rocky, water ocean, hydrogen rich) and the spectral type of the parent star (M and K stars). For some cases, we applied coupled climate chemistry, or climate-only calculations; for other cases, we assumed the atmospheric composition, ground temperature, and surface reflectivity. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1938DOI Listing

Fungi and Mycotoxins in Space-A Review.

Astrobiology 2019 Apr 11. Epub 2019 Apr 11.

1 Laboratory of Food Analysis, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.

Fungi are not only present on Earth but colonize spacecraft and space stations as well. This review provides an extensive overview of the large and diverse group of fungal species that have been found in space, as well as those corresponding detection methods used and the existing and potential future prevention and control strategies. Many of the identified fungal species in space, such as Aspergillus flavus and Alternaria sp. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1854DOI Listing

A Simple Instrument Suite for Characterizing Habitability and Weathering: The Modern Aqueous Habitat Reconnaissance Suite (MAHRS).

Astrobiology 2019 Apr 9. Epub 2019 Apr 9.

1 Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan.

The shallow subsurface of Mars is extremely interesting as a possible microbial habitat because it becomes temporarily wet, it is shielded from radiation, and mixing by aeolian processes could provide the sources of energy and nutrients necessary for sustaining microbial life in it. The Modern Aqueous Habitat Reconnaissance Suite (MAHRS) was developed primarily to search for potentially habitable environments in the shallow subsurface of Mars and to study weathering, but it can also be used to search for potentially habitable environments in the shallow subsurface of other planetary bodies such as the Icy Worlds. MAHRS includes an instrument developed to measure regolith wetness and search for brine in the shallow subsurface of Mars, where it is most likely to be found. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1945DOI Listing

Self-Assembling Ice Membranes on Europa: Brinicle Properties, Field Examples, and Possible Energetic Systems in Icy Ocean Worlds.

Astrobiology 2019 Apr 9. Epub 2019 Apr 9.

3 Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, Granada, Spain.

Brinicles are self-assembling tubular ice membrane structures, centimeters to meters in length, found beneath sea ice in the polar regions of Earth. We discuss how the properties of brinicles make them of possible importance for chemistry in cold environments-including that of life's emergence-and we consider their formation in icy ocean worlds. We argue that the non-ice composition of the ice on Europa and Enceladus will vary spatially due to thermodynamic and mechanical properties that serve to separate and fractionate brines and solid materials. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1826DOI Listing

Microbial Activity and Habitability of an Antarctic Dry Valley Water Track.

Astrobiology 2019 Apr 8. Epub 2019 Apr 8.

1 Department of Natural Resource Sciences, McGill University, Montreal, Canada.

Water tracks in the Antarctic Dry Valleys are dark linear features of increased soil moisture that flow downslope over the spring and summer, providing a source of moisture in a cold-arid desert. They are typically sourced from melting snow, ground ice, and deliquescence (Levy et al., 2011 ). Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1884DOI Listing

A Maximum Subsurface Biomass on Mars from Untapped Free Energy: CO and H as Potential Antibiosignatures.

Astrobiology 2019 Apr 5. Epub 2019 Apr 5.

1 Department of Earth and Space Sciences, University of Washington, Seattle, Washington.

Whether extant life exists in the martian subsurface is an open question. High concentrations of photochemically produced CO and H in the otherwise oxidizing martian atmosphere represent untapped sources of biologically useful free energy. These out-of-equilibrium species diffuse into the regolith, so subsurface microbes could use them as a source of energy and carbon. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1835DOI Listing

Tolerances of Deinococcus geothermalis Biofilms and Planktonic Cells Exposed to Space and Simulated Martian Conditions in Low Earth Orbit for Almost Two Years.

Astrobiology 2019 Mar 29. Epub 2019 Mar 29.

3 Research Group Astrobiology, Radiation Biology Department, Institute of Aerospace Medicine, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Cologne, Germany.

Fossilized biofilms represent one of the oldest known confirmations of life on the Earth. The success of microbes in biofilms results from properties that are inherent in the biofilm, including enhanced interaction, protection, and biodiversity. Given the diversity of microbes that live in biofilms in harsh environments on the Earth, it is logical to hypothesize that, if microbes inhabit other bodies in the Universe, there are also biofilms on those bodies. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1913DOI Listing
March 2019
1 Read

Prebiotic Chemistry of Pluto.

Astrobiology 2019 Mar 23. Epub 2019 Mar 23.

9 Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona, USA.

We present the case for the presence of complex organic molecules, such as amino acids and nucleobases, formed by abiotic processes on the surface and in near-subsurface regions of Pluto. Pluto's surface is tinted with a range of non-ice substances with colors ranging from light yellow to red to dark brown; the colors match those of laboratory organic residues called tholins. Tholins are broadly characterized as complex, macromolecular organic solids consisting of a network of aromatic structures connected by aliphatic bridging units (e. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1927DOI Listing

Trivalent Phosphorus and Phosphines as Components of Biochemistry in Anoxic Environments.

Astrobiology 2019 Mar 21. Epub 2019 Mar 21.

2 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts.

Phosphorus is an essential element for all life on Earth, yet trivalent phosphorus (e.g., in phosphines) appears to be almost completely absent from biology. Read More

View Article

Download full-text PDF

Source
https://www.liebertpub.com/doi/10.1089/ast.2018.1958
Publisher Site
http://dx.doi.org/10.1089/ast.2018.1958DOI Listing
March 2019
4 Reads

Recovery of Fatty Acids from Mineralogic Mars Analogs by TMAH Thermochemolysis for the Sample Analysis at Mars Wet Chemistry Experiment on the Curiosity Rover.

Astrobiology 2019 Apr 14;19(4):522-546. Epub 2019 Mar 14.

3 Space Science Exploration Division (Code 690), NASA Goddard Space Flight Center, Greenbelt, Maryland, USA.

The Mars Curiosity rover carries a diverse instrument payload to characterize habitable environments in the sedimentary layers of Aeolis Mons. One of these instruments is Sample Analysis at Mars (SAM), which contains a mass spectrometer that is capable of detecting organic compounds via pyrolysis gas chromatography mass spectrometry (py-GC-MS). To identify polar organic molecules, the SAM instrument carries the thermochemolysis reagent tetramethylammonium hydroxide (TMAH) in methanol (hereafter referred to as TMAH). Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1819DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6459279PMC

FameLab USA: Improving Science Communication Skills for Early Career Scientists.

Astrobiology 2019 Apr 11;19(4):614-623. Epub 2019 Mar 11.

6 National Aeronautics and Space Administration, Washington, DC.

FameLab International is a science communication competition for early career scientists pioneered by the Cheltenham Science Festival in the United Kingdom in 2005. At its heart is training in the best practices and techniques of good communication. NASA's Astrobiology Program and its partners implemented FameLab USA, one of over 30 implementations around the globe, from 2012 to 2016. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2017.1809DOI Listing

The BASALT Research Program: Designing and Developing Mission Elements in Support of Human Scientific Exploration of Mars.

Astrobiology 2019 Mar;19(3):245-259

2 NASA Ames Research Center, Moffett Field, California.

The articles associated with this Special Collection focus on the NASA BASALT (Biologic Analog Science Associated with Lava Terrains) Research Program, which aims at answering the question, "How do we support and enable scientific exploration during human Mars missions?" To answer this the BASALT team conducted scientific field studies under simulated Mars mission conditions to both broaden our understanding of the habitability potential of basalt-rich terrains on Mars and examine the effects of science on current Mars mission concepts of operations. This article provides an overview of the BASALT research project, from the science, to the operational concepts that were tested and developed, to the technical capabilities that supported all elements of the team's research. Further, this article introduces the 12 articles that are included in this Special Collection. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1869DOI Listing

Opportunities and Challenges of Promoting Scientific Dialog throughout Execution of Future Science-Driven Extravehicular Activity.

Astrobiology 2019 Mar;19(3):426-439

4 NASA Ames Research Center, Moffett Field, California, USA.

Science-driven, human spaceflight missions of the future will rely on regular and interactive communication between Earth- and space-based teams during activity in which astronauts work directly on Mars or other planetary surfaces (extravehicular activity, EVA). The Biologic Analog Science Associated with Lava Terrains (BASALT) project conducted simulated human missions to Mars, complete with realistic one-way light time (OWLT) communication latency. We discuss the modes of communication used by the Mars- and Earth-based teams, including text, audio, video, and still imagery. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1901DOI Listing

Developing Intra-EVA Science Support Team Practices for a Human Mission to Mars.

Astrobiology 2019 Mar;19(3):387-400

3 BAER Institute, Moffett Field, California, USA.

During the BASALT research program, real (nonsimulated) geological and biological science was accomplished through a series of extravehicular activities (EVAs) under simulated Mars mission conditions. These EVAs were supported by a Mission Support Center (MSC) that included an on-site, colocated Science Support Team (SST). The SST was composed of scientists from a variety of disciplines and operations researchers who provided scientific and technical expertise to the crew while each EVA was being conducted (intra-EVA). Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1846DOI Listing
March 2019
2 Reads

Assessing the Acceptability of Science Operations Concepts and the Level of Mission Enhancement of Capabilities for Human Mars Exploration Extravehicular Activity.

Astrobiology 2019 Mar;19(3):321-346

7 BAER Institute, Moffett Field, California, USA.

The Biologic Analog Science Associated with Lava Terrains (BASALT) research project is investigating tools, techniques, and strategies for conducting Mars scientific exploration extravehicular activity (EVA). This has been accomplished through three science-driven terrestrial field tests (BASALT-1, BASALT-2, and BASALT-3) during which the iterative development, testing, assessment, and refinement of concepts of operations (ConOps) and capabilities were conducted. ConOps are the instantiation of operational design elements that guide the organization and flow of personnel, communication, hardware, software, and data products to enable a mission concept. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1912DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442237PMC

Requirements for Portable Instrument Suites during Human Scientific Exploration of Mars.

Astrobiology 2019 Mar;19(3):401-425

1 NASA Ames Research Center, Moffett Field, California.

Human explorers on the surface of Mars will have access to a far wider array of scientific tools than previous crewed planetary exploration missions, but not every tool will be compatible with the restrictions of this exploration. Spectrometers on flyby, orbital, and landed missions are currently used to determine the composition and mineralogy of geological materials of various types and sizes, from small fragments to celestial bodies in the solar system. Handheld spectrometers that are capable of in situ analyses are already used for geological exploration on Earth; however, their usefulness for human exploration missions and how data from multiple handheld instruments could be combined to enhance scientific return must be further evaluated. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1841DOI Listing

Future Needs for Science-Driven Geospatial and Temporal Extravehicular Activity Planning and Execution.

Astrobiology 2019 Mar;19(3):440-461

1 NASA Ames Research Center, Moffett Field, California.

Future human missions to Mars are expected to emphasize scientific exploration. While recent Mars rover missions have addressed a wide range of science objectives, human extravehicular activities (EVAs), including the Apollo missions, have had limited experience with science operations. Current EVAs are carefully choreographed and guided continuously from Earth with negligible delay in communications between crew and flight controllers. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1838DOI Listing
March 2019
3 Reads

Developing Future Deep-Space Telecommunication Architectures: A Historical Look at the Benefits of Analog Research on the Development of Solar System Internetworking for Future Human Spaceflight.

Astrobiology 2019 Mar;19(3):462-477

4 NASA, Kennedy Space Center, KSC, Florida.

Exploration analog field tests, missions, and deployments enable the integration and validation of new and experimental concepts and/or technologies through strategic experimental design. The results of these operations often create new capabilities for exploration and increase confidence in, and credibility of, emerging technologies, usually at very low cost and risk to the test subjects involved. While these experiments resemble missions 10-30 years into the future, insights obtained are often of immediate value. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1915DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442236PMC
March 2019
1 Read

Tactical Scientific Decision-Making during Crewed Astrobiology Mars Missions.

Astrobiology 2019 Mar;19(3):369-386

7 NASA Ames Research Center, Moffett Field, California, USA.

The limitations placed upon human explorers on the surface of Mars will necessitate a methodology for scientific exploration that is different from standard approaches to terrestrial fieldwork and prior crewed exploration of the Moon. In particular, the data transmission limitations and communication latency between Earth and Mars create a unique situation for surface crew in contact with a terrestrial science team. The BASALT research program simulated a series of extravehicular activities (EVAs) in Mars analog terrains under various Mars-relevant bandwidth and latency conditions to investigate how best to approach this problem. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1837DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442282PMC
March 2019
2 Reads

A Flexible Telecommunication Architecture for Human Planetary Exploration Based on the BASALT Science-Driven Mars Analog.

Astrobiology 2019 Mar;19(3):478-496

3 NASA Ames Research Center, Moffett Field, California.

There is a synergistic relationship between analog field testing and the deep space telecommunication capabilities necessary for future human exploration. The BASALT (Biologic Analog Science Associated with Lava Terrains) research project developed and implemented a telecommunications architecture that serves as a high-fidelity analog of future telecommunication capabilities for Mars. This paper presents the architecture and its constituent elements. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1906DOI Listing

A Low-Diversity Microbiota Inhabits Extreme Terrestrial Basaltic Terrains and Their Fumaroles: Implications for the Exploration of Mars.

Astrobiology 2019 Mar;19(3):284-299

6 NASA Ames Research Center, Mountain View, California, USA.

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. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1870DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442273PMC
March 2019
2 Reads

Strategic Planning Insights for Future Science-Driven Extravehicular Activity on Mars.

Astrobiology 2019 Mar;19(3):347-368

4 NASA Ames Research Center, Moffett Field, California.

Short-term and long-term science plans were developed as part of the strategic planning process used by the Biologic Analog Science Associated with Lava Terrains (BASALT) science team to conduct two Mars-simulation missions investigating basalt habitability at terrestrial volcanic analog sites in 2016. A multidisciplinary team of scientists generated and codified a range of scientific hypotheses distilled into a Science Traceability Matrix (STM) that defined the set of objectives pursued in a series of extravehicular activity (EVA) campaigns performed across multiple field deployments. This STM was used to guide the pre-deployment selection of sampling stations within the selected Mars analog sites on the Earth based on precursor site information such as multispectral imagery. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1850DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442241PMC

Using Science-Driven Analog Research to Investigate Extravehicular Activity Science Operations Concepts and Capabilities for Human Planetary Exploration.

Astrobiology 2019 Mar;19(3):300-320

7 BAER Institute, Moffett Field, California.

Biologic Analog Science Associated with Lava Terrains (BASALT) is a science-driven exploration program seeking to determine the best tools, techniques, training requirements, and execution strategies for conducting Mars-relevant field science under spaceflight mission conditions. BASALT encompasses Science, Science Operations, and Technology objectives. This article outlines the BASALT Science Operations background, strategic research questions, study design, and a portion of the results from the second field test. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1861DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442238PMC

WATSON: In Situ Organic Detection in Subsurface Ice Using Deep-UV Fluorescence Spectroscopy.

Astrobiology 2019 Mar 1. Epub 2019 Mar 1.

1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California.

Terrestrial icy environments have been found to preserve organic material and contain habitable niches for microbial life. The cryosphere of other planetary bodies may therefore also serve as an accessible location to search for signs of life. The Wireline Analysis Tool for the Subsurface Observation of Northern ice sheets (WATSON) is a compact deep-UV fluorescence spectrometer for nondestructive ice borehole analysis and spatial mapping of organics and microbes, intended to address the heterogeneity and low bulk densities of organics and microbial cells in ice. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1925DOI Listing
March 2019
1 Read

Evidence for Biotic Perchlorate Reduction in Naturally Perchlorate-Rich Sediments of Pilot Valley Basin, Utah.

Astrobiology 2019 Mar 1. Epub 2019 Mar 1.

5 Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado.

The presence of perchlorate on Mars suggests a possible energy source for sustaining microbial life. Perchlorate-reducing microbes have been isolated from perchlorate-contaminated soils and sediments on the Earth, but to date, never from an environment that is naturally enriched in perchlorate. The arid Pilot Valley paleolake basin in Utah is a Mars analog environment whose sediments are naturally enriched with up to ∼6. Read More

View Article

Download full-text PDF

Source
https://www.liebertpub.com/doi/10.1089/ast.2018.1864
Publisher Site
http://dx.doi.org/10.1089/ast.2018.1864DOI Listing
March 2019
5 Reads

Photochemistry on the Space Station-Aptamer Resistance to Space Conditions: Particles Exposure from Irradiation Facilities and Real Exposure Outside the International Space Station.

Astrobiology 2019 Feb 28. Epub 2019 Feb 28.

2 Laboratoire d'Astrophysique de Bordeaux (LAB), Université de Bordeaux, CNRS, B18N, Pessac, France.

Some microarray-based instruments that use bioaffinity receptors such as antibodies or aptamers are under development to detect signatures of past or present life on planetary bodies. Studying the resistance of such instruments against space constraints and cosmic rays in particular is a prerequisite. We used several ground-based facilities to study the resistance of aptamers to various types of particles (protons, electrons, neutrons, and carbon ions) at different energies and fluences. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1896DOI Listing
February 2019
1 Read

Photochemistry on the Space Station-Antibody Resistance to Space Conditions after Exposure outside the International Space Station.

Astrobiology 2019 Feb 28. Epub 2019 Feb 28.

2 Laboratoire d'Astrophysique de Bordeaux (LAB), Université de Bordeaux, CNRS, Pessac, France.

Antibody-based analytical instruments are under development to detect signatures of life on planetary bodies. Antibodies are molecular recognition reagents able to detect their target at sub-nanomolar concentrations, with high affinity and specificity. Studying antibody binding performances under space conditions is mandatory to convince space agencies of the adequacy of this promising tool for planetary exploration. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1907DOI Listing
February 2019
1 Read

A Lunar Microbial Survival Model for Predicting the Forward Contamination of the Moon.

Astrobiology 2019 Feb 27. Epub 2019 Feb 27.

4 Department of Radiation Dosimetry, Nuclear Physics Institute of the CAS, Praha, Czech Republic.

The surface conditions on the Moon are extremely harsh with high doses of ultraviolet (UV) irradiation (26.8 W · m UVC/UVB), wide temperature extremes (-171°C to 140°C), low pressure (10 Pa), and high levels of ionizing radiation. External spacecraft surfaces on the Moon are generally >100°C during daylight hours and can reach as high as 140°C at local noon. Read More

View Article

Download full-text PDF

Source
https://www.liebertpub.com/doi/10.1089/ast.2018.1952
Publisher Site
http://dx.doi.org/10.1089/ast.2018.1952DOI Listing
February 2019
6 Reads

Diving into Exoplanets: Are Water Seas the Most Common?

Astrobiology 2019 Feb 21. Epub 2019 Feb 21.

1 Observatori Astronòmic, Universitat de València, Paterna (València), Spain.

One of the basic tenets of exobiology is the need for a liquid substratum in which life can arise, evolve, and develop. The most common version of this idea involves the necessity of water to act as such a substratum, both because that is the case on Earth and because it seems to be the most viable liquid for chemical reactions that lead to life. Other liquid media that could harbor life, however, have occasionally been put forth. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2017.1720DOI Listing
February 2019

Biological Contamination Prevention for Outer Solar System Moons of Astrobiological Interest: What Do We Need to Know?

Astrobiology 2019 Feb 14. Epub 2019 Feb 14.

15 Eurospace, Paris, France.

To ensure that scientific investments in space exploration are not compromised by terrestrial contamination of celestial bodies, special care needs to be taken to preserve planetary conditions for future astrobiological exploration. Significant effort has been made and is being taken to address planetary protection in the context of inner Solar System exploration. In particular for missions to Mars, detailed internationally accepted guidelines have been established. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1996DOI Listing
February 2019

Mosses in Low Earth Orbit: Implications for the Limits of Life and the Habitability of Mars.

Astrobiology 2019 Feb;19(2):221-232

1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany.

As a part of the European Space Agency mission "EXPOSE-R2" on the International Space Station (ISS), the BIOMEX (Biology and Mars Experiment) experiment investigates the habitability of Mars and the limits of life. In preparation for the mission, experimental verification tests and scientific verification tests simulating different combinations of abiotic space- and Mars-like conditions were performed to analyze the resistance of a range of model organisms. The simulated abiotic space- and Mars-stressors were extreme temperatures, vacuum, and Mars-like surface ultraviolet (UV) irradiation in different atmospheres. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1889DOI Listing
February 2019
6 Reads

Response of Methanogenic Archaea from Siberian Permafrost and Non-permafrost Environments to Simulated Mars-like Desiccation and the Presence of Perchlorate.

Astrobiology 2019 Feb;19(2):197-208

1 GFZ, German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section Geomicrobiology, Potsdam, Germany.

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. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1877DOI Listing
February 2019
1 Read

A Desert Cyanobacterium under Simulated Mars-like Conditions in Low Earth Orbit: Implications for the Habitability of Mars.

Astrobiology 2019 Feb;19(2):158-169

2 German Aerospace Center, Institute of Planetary Research, Management and Infrastructure, Astrobiological Laboratories, Berlin, Germany.

In the ESA space experiment BIOMEX (BIOlogy and Mars EXperiment), dried Chroococcidiopsis cells were exposed to Mars-like conditions during the EXPOSE-R2 mission on the International Space Station. The samples were exposed to UV radiation for 469 days and to a Mars-like atmosphere for 722 days, approaching the conditions that could be faced on the surface of Mars. Once back on Earth, cell survival was tested by growth-dependent assays, while confocal laser scanning microscopy and PCR-based assay were used to analyze the accumulated damage in photosynthetic pigments (chlorophyll a and phycobiliproteins) and genomic DNA, respectively. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2017.1807DOI Listing
February 2019
6 Reads

Limits of Life and the Habitability of Mars: The ESA Space Experiment BIOMEX on the ISS.

Astrobiology 2019 Feb;19(2):145-157

23 Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy.

BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1897DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6383581PMC
February 2019
6 Reads

Characterization of Viability of the Lichen Buellia frigida After 1.5 Years in Space on the International Space Station.

Astrobiology 2019 Feb;19(2):233-241

1 Institute of Botany, Heinrich Heine University, Duesseldorf, Germany.

The lichen Buellia frigida was exposed to space and simulated Mars analog conditions in the Biology and Mars Experiment (BIOMEX) project operated outside the International Space Station (ISS) for 1.5 years. To determine the effects of the Low Earth Orbit (LEO) conditions on the lichen symbionts, a LIVE/DEAD staining analysis test was performed. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1894DOI Listing
February 2019
2 Reads

Dried Biofilms of Desert Strains of Chroococcidiopsis Survived Prolonged Exposure to Space and Mars-like Conditions in Low Earth Orbit.

Astrobiology 2019 Feb 11. Epub 2019 Feb 11.

3 German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany.

Dried biofilms and dried multilayered planktonic counterparts obtained from three desert strains of Chroococcidiopsis were exposed to low Earth conditions by using the EXPOSE-R2 facility outside the International Space Station. During the space mission, samples in Tray 1 (space vacuum and solar radiation, from λ ≈ 110 nm) and Tray 2 (Mars-like UV flux, λ > 200 nm and Mars-like atmosphere) received total UV (200-400 nm) fluences of about 4.58 × 10 kJ/m and 4. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1900DOI Listing
February 2019
1 Read

Prebiotic Oligomer Assembly: What Was the Energy Source?

Astrobiology 2019 Apr 1;19(4):517-521. Epub 2019 Feb 1.

2 Department of Biomolecular Engineering, University of California, Santa Cruz, California.

Polymerization of nucleotides and amino acids to form large, complex, and potentially functional products was an early and essential event on the paths leading to life's origin. The standard Gibbs energies of the condensation reactions are uphill, however, and at equilibrium will yield only declining sequences of small, nonfunctional oligomers. Geochemically produced condensing agents such as carbonyl sulfide, cyanamide, and polyphosphates have been proposed to invert the unfavorable condensation Gibbs energies and thereby activate exergonic condensation. Read More

View Article

Download full-text PDF

Source
https://www.liebertpub.com/doi/10.1089/ast.2018.1918
Publisher Site
http://dx.doi.org/10.1089/ast.2018.1918DOI Listing
April 2019
8 Reads

The Power Without the Glory: Multiple Roles of Hydrogen Peroxide in Mediating the Origin of Life.

Astrobiology 2019 Feb 1. Epub 2019 Feb 1.

2 School of Mathematics, University of Leeds, Leeds, United Kingdom.

The hydrogen peroxide (HP) crucible hypothesis proposed here holds that life began in a localized environment on Earth that was perfused with a flow of hydrogen peroxide from a sustained external source, which powered and mediated molecular evolution and the protocellular RNA world. In this article, we consolidate and review recent evidence, both circumstantial and tested in simulation in our work and in the laboratory in others' work, for its multiple roles in the evolution of the first living systems: (1) it provides a periodic power source as the thiosulfate-hydrogen peroxide (THP) redox oscillator, (2) it may act as an agent of molecular change and evolution and mediator of homochirality, and (3) the THP oscillator, subject to Brownian input perturbations, produces a weighted distribution of output thermal fluctuations that favor polymerization and chemical diversification over chemical degradation and simplification. The hypothesis can help to clarify the hero and villain roles of hydrogen peroxide in cell function, and on the singularity of life: of necessity, life evolved early an armory of catalases, the continuing, and all-pervasive presence of which prevents hydrogen peroxide from accumulating anywhere in sufficient quantities to host a second origin. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1886DOI Listing
February 2019

A Prebiotic Synthesis of Canonical Pyrimidine and Purine Ribonucleotides.

Astrobiology 2019 Jan 30. Epub 2019 Jan 30.

1 Firebird Biomolecular Sciences LLC, Alachua, Florida.

The "RNA first" model for the origin of life holds that RNA emerged spontaneously on early Earth and developed into life through its dual capabilities for genetics and catalysis. The model's central weakness is the difficulty of making its building blocks, in particular, the glycosidic bond joining nucleobases to ribose. Thus, the focus of much of the modern literature on the topic is directed toward solving this difficulty and includes elegant, though indirect, methods for making this bond. Read More

View Article

Download full-text PDF

Source
https://www.liebertpub.com/doi/10.1089/ast.2018.1935
Publisher Site
http://dx.doi.org/10.1089/ast.2018.1935DOI Listing
January 2019
17 Reads

From Planetary Quarantine to Planetary Protection: A NASA and International Story.

Authors:
John D Rummel

Astrobiology 2019 Apr 29;19(4):624-627. Epub 2019 Jan 29.

SETI Institute, Mountain View, California.

This paper treats the very specific history of one aspect of space policy and how it, or more specifically its name, developed in the first two decades of the Space Age. The concepts of preventing the biological and organic contamination of other planetary bodies, which also protect the biosphere from the consequences of finding extraterrestrial life and returning it to Earth, were established in the late 1950s with the beginning of the Space Age. Within their first decade, those concepts were labeled "planetary quarantine," a name that suggested the concepts but unfortunately came with latent baggage of its own. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1944DOI Listing

Photolysis of Cometary Organic Dust Analogs on the EXPOSE-R2 Mission at the International Space Station.

Astrobiology 2019 Jan 17. Epub 2019 Jan 17.

1 INAF - Osservatorio Astrofisico di Catania, Catania, Italy.

We describe the results obtained on a set of organic samples that have been part of the experiment "Photochemistry on the Space Station (PSS)" on the EXPOSE-R2 mission conducted on the EXPOSE-R facility situated outside the International Space Station (ISS). The organic samples were prepared in the Catania laboratory by 200 keV He irradiation of N:CH:CO icy mixtures deposited at 17 K, on vacuum UV (VUV) transparent MgF windows. This organic material contains different chemical groups, including triple CN bonds, that are thought to be of interest for astrobiology. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1853DOI Listing
January 2019

The Dallol Geothermal Area, Northern Afar (Ethiopia)-An Exceptional Planetary Field Analog on Earth.

Astrobiology 2019 Apr 17;19(4):553-578. Epub 2019 Jan 17.

9 Department of Earth Sciences, Mekelle University, Mekelle, Ethiopia.

The Dallol volcano and its associated hydrothermal field are located in a remote area of the northern Danakil Depression in Ethiopia, a region only recently appraised after decades of inaccessibility due to severe political instability and the absence of infrastructure. The region is notable for hosting environments at the very edge of natural physical-chemical extremities. It is surrounded by a wide, hyperarid salt plain and is one of the hottest (average annual temperature: 36-38°C) and most acidic natural systems (pH ≈0) on Earth. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1926DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6459281PMC
April 2019
1 Read

Hydroxymethanesulfonate from Volcanic Sulfur Dioxide: A "Mineral" Reservoir for Formaldehyde and Other Simple Carbohydrates in Prebiotic Chemistry.

Astrobiology 2019 Apr 7;19(4):506-516. Epub 2019 Jan 7.

1 Foundation for Applied Molecular Evolution, Alachua, Florida, USA.

While formaldehyde (HCHO) was likely generated in Earth's prebiotic atmosphere by ultraviolet light, electrical discharge, and/or volcano-created lightning, HCHO could not have accumulated in substantial amounts in prebiotic environments, including those needed for prebiotic processes that generate nucleosidic carbohydrates. HCHO at high concentrations in alkaline solutions self-reacts in the Cannizzaro reaction to give methanol and formate, neither having prebiotic value. Here, we explore the possibility that volcanic sulfur dioxide (SO) might have generated a reservoir for Hadean HCHO by a reversible reaction with HCHO to give hydroxymethanesulfonate (HMS). Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2017.1800DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6459274PMC
April 2019
2 Reads

Experimental Constraints on Abiotic Formation of Tubules and Other Proposed Biological Structures in Subsurface Volcanic Glass.

Astrobiology 2019 Jan;19(1):53-63

Laboratory for Atmospheric and Space Physics, University of Colorado , Boulder, Colorado.

Formation of microtubules in volcanic glass from subsurface environments has been widely attributed to in situ activity of micro-organisms, but evidence directly linking those structures to biological processes remains lacking. Investigations into the alternative possibility of abiotic tubule formation have been limited. A laboratory experiment was conducted to examine whether moderate-temperature hydrothermal alteration of basaltic glass by seawater would produce structures similar to those ascribed to biological processes. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2017.1811DOI Listing
January 2019
2 Reads

Relative Likelihood of Success in the Search for Primitive versus Intelligent Extraterrestrial Life.

Astrobiology 2019 Jan 15;19(1):28-39. Epub 2018 Dec 15.

Institute for Theory and Computation, Harvard University , Cambridge, Massachusetts.

We estimate the relative likelihood of success in the searches for primitive versus intelligent life on other planets. Taking into account the larger search volume for detectable artificial electromagnetic signals, we conclude that both searches should be performed concurrently, albeit with significantly more funding dedicated to primitive life. Based on the current federal funding allocated to the search for biosignatures, our analysis suggests that the search for extraterrestrial intelligence (SETI) may merit a federal funding level of at least $10 million per year, assuming that the average lifetime of technological species exceeds a millennium. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1936DOI Listing
January 2019

Multimicrobial Kombucha Culture Tolerates Mars-Like Conditions Simulated on Low-Earth Orbit.

Astrobiology 2019 Feb 28;19(2):183-196. Epub 2018 Nov 28.

9 Astrobiological Laboratories, German Aerospace Center (DLR) Berlin, Institute of Planetary Research, Management and Infrastructure, Berlin, Germany.

A kombucha multimicrobial culture (KMC) was exposed to simulated Mars-like conditions in low-Earth orbit (LEO). The study was part of the Biology and Mars Experiment (BIOMEX), which was accommodated in the European Space Agency's EXPOSE-R2 facility, outside the International Space Station. The aim of the study was to investigate the capability of a KMC microecosystem to survive simulated Mars-like conditions in LEO. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2017.1746DOI Listing
February 2019
3 Reads

Hypothesis: Muon Radiation Dose and Marine Megafaunal Extinction at the End-Pliocene Supernova.

Astrobiology 2018 Nov 27. Epub 2018 Nov 27.

3 Universidade Federal do ABC , Santo André, Brazil .

Considerable data and analysis support the detection of one or more supernovae (SNe) at a distance of about 50 pc, ∼2.6 million years ago. This is possibly related to the extinction event around that time and is a member of a series of explosions that formed the Local Bubble in the interstellar medium. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2018.1902DOI Listing
November 2018

An Apparent Binary Choice in Biochemistry: Mutual Reactivity Implies Life Chooses Thiols or Nitrogen-Sulfur Bonds, but Not Both.

Astrobiology 2019 Apr 22;19(4):579-613. Epub 2018 Nov 22.

1 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA.

A fundamental goal of biology is to understand the rules behind life's use of chemical space. Established work focuses on why life uses the chemistry that it does. Given the enormous scope of possible chemical space, we postulate that it is equally important to ask why life largely avoids certain areas of chemical space. Read More

View Article

Download full-text PDF

Source
https://www.liebertpub.com/doi/10.1089/ast.2018.1831
Publisher Site
http://dx.doi.org/10.1089/ast.2018.1831DOI Listing
April 2019
9 Reads

Organization and Compartmentalization by Lipid Membranes Promote Reactions Related to the Origin of Cellular Life.

Astrobiology 2019 Apr 15;19(4):547-552. Epub 2018 Nov 15.

N.C.S.R. «Demokritos», Institute of Nanoscience and Nanotechnology , Attiki, Greece .

Liquid crystals have certain physical properties that promote chemical reactions which cannot occur in bulk phase media. These properties are displayed, among other molecules, by amphiphilic compounds which assemble into membrane structures then concentrate and organize biologically relevant monomers within their confined spaces. When mixtures of lipids and nucleotides are cycled multiple times between hydrated and anhydrous conditions, the monomers polymerize in the dry phase into oligonucleotides. Read More

View Article

Download full-text PDF

Source
https://www.liebertpub.com/doi/10.1089/ast.2018.1832
Publisher Site
http://dx.doi.org/10.1089/ast.2018.1832DOI Listing
April 2019
15 Reads