Constraints on the Metabolic Activity of Microorganisms in Atacama Surface Soils Inferred from Refractory Biomarkers: Implications for Martian Habitability and Biomarker Detection.

abstract：:Microbial contamination of human-tended spacecraft is unavoidable, making the study of microbial growth under space conditions essential for the preservation of astronauts' health and equipment integrity. Previous studies suggested that spaceflight conditions, such as microgravity, cause a range of physiological micro...

journal_title：Astrobiology

authors： Garschagen LS,Mancinelli RL,Moeller R

更新日期：2019-10-01 00:00:00

abstract：:Following the suggestion that nucleoside analogues having their nucleobases joined to ribose via a carbon-carbon bond might easily arise prebiotically, the glycosylation of uracil carrying electron-donating substituents (Me, OH, OCH3, NH2) at its 5 or 6 positions was investigated. Of these, only 6-aminouracil gave gly...

journal_title：Astrobiology

authors： Kim HJ,Benner SA

更新日期：2015-04-01 00:00:00

abstract：:Laser-Raman imagery is a non-intrusive, non-destructive analytical technique, recently introduced to Precambrian paleobiology, that can be used to demonstrate a one-to-one spatial correlation between the optically discernible morphology and kerogenous composition of permineralized fossil microorganisms. Made possible ...

journal_title：Astrobiology

authors： Schopf JW,Kudryavtsev AB,Agresti DG,Czaja AD,Wdowiak TJ

更新日期：2005-06-01 00:00:00

abstract：:The Mars Organic Analyzer (MOA) has enabled the sensitive detection of amino acid and amine biomarkers in laboratory standards and in a variety of field sample tests. However, the MOA is challenged when samples are extremely acidic and saline or contain polyvalent cations. Here, we have optimized the MOA analysis, sam...

journal_title：Astrobiology

authors： Stockton AM,Chiesl TN,Lowenstein TK,Amashukeli X,Grunthaner F,Mathies RA

更新日期：2009-11-01 00:00:00

abstract：:The emergence of an RNA entity capable of synthesizing peptides was a key prebiotic development. It is hypothesized that a precursor of the modern ribosomal exit tunnel was associated with this RNA entity (e.g., "protoribosome" or "bonding entity") from the earliest time and played an essential role. Various compounds...

journal_title：Astrobiology

authors： Fox GE,Tran Q,Yonath A

更新日期：2012-01-01 00:00:00

abstract：:Remote sensing data are abundant, whereas surface in situ verification of atmospheric conditions is rare on Mars. Earth-based analogs could help gain an understanding of soil and atmospheric processes on Mars and refine existing models. In this work, we evaluate the applicability of the Weather Research and Forecastin...

journal_title：Astrobiology

authors： Breuer H,Berényi A,Mari L,Nagy B,Szalai Z,Tordai Á,Weidinger T

更新日期：2020-06-01 00:00:00

abstract：:Meaningful motion is an unambiguous biosignature, but because life in the Solar System is most likely to be microbial, the question is whether such motion may be detected effectively on the micrometer scale. Recent results on microbial motility in various Earth environments have provided insight into the physics and b...

journal_title：Astrobiology

authors： Nadeau J,Lindensmith C,Deming JW,Fernandez VI,Stocker R

更新日期：2016-10-01 00:00:00

abstract：:The Atacama Desert has long been considered a good Mars analogue for testing instrumentation for planetary exploration, but very few data (if any) have been reported about the geomicrobiology of its salt-rich subsurface. We performed a Mars analogue drilling campaign next to the Salar Grande (Atacama, Chile) in July 2...

journal_title：Astrobiology

authors： Parro V,de Diego-Castilla G,Moreno-Paz M,Blanco Y,Cruz-Gil P,Rodríguez-Manfredi JA,Fernández-Remolar D,Gómez F,Gómez MJ,Rivas LA,Demergasso C,Echeverría A,Urtuvia VN,Ruiz-Bermejo M,García-Villadangos M,Postigo M,Sánchez-R

更新日期：2011-12-01 00:00:00

abstract：:Oligonucleotides are structurally similar to short RNA strands. Therefore, their formation via non-enzymatic reactions is highly relevant to Gilbert's RNA world scenario (1986) and the origin of life. In laboratory synthesis of oligonucleotides from monomers, it is necessary to remove the water molecules from the reac...

journal_title：Astrobiology

authors： Ertem G,Hazen RM,Dworkin JP

更新日期：2007-10-01 00:00:00

abstract：:The five major mass extinctions identified in 1982 by Raup and Sepkoski have expanded to six, with the suggestion that the Permian-Triassic extinction was a double event. Is there a general explanation for great mass extinctions, or can they result from different triggers, or even from internal system instabilities? T...

journal_title：Astrobiology

authors： Alvarez W

更新日期：2003-04-01 00:00:00

abstract：:In this work, we provide an answer to the question formulated by Albert Eschenmoser: "How would you envisage the bridge between potentially primordial geochemistry that had been disordered and one that gradually became self-organizing?" Analysis of the free-energy profiles of some of the key reactions leading to forma...

journal_title：Astrobiology

authors： Šponer JE,Šponer J,Di Mauro E

更新日期：2019-09-01 00:00:00

abstract：:Lunar dust toxicity has to be evaluated in view of future manned missions to the Moon. Previous studies on lunar specimens and simulated dusts have revealed an oxidant activity assigned to HO· release. However, the mechanisms behind the reactivity of lunar dust are still quite unclear at the molecular level. In the pr...

journal_title：Astrobiology

authors： Turci F,Corazzari I,Alberto G,Martra G,Fubini B

更新日期：2015-05-01 00:00:00

abstract：:The γ-radiolysis of fullerenes (C60 and C70) was performed to investigate the role of fullerenes as a carbon source in building organic molecules in astrophysical ice analog media. Mass spectrometric analyses and the sequential collision-induced dissociation processes enabled us to determine the plausible chemical str...

journal_title：Astrobiology

authors： Ursini O,Angelini G,Cataldo F,Iglesias-Groth S

更新日期：2019-07-01 00:00:00

abstract：: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 c...

journal_title：Astrobiology

authors： De Middeleer G,Leys N,Sas B,De Saeger S

更新日期：2019-07-01 00:00:00

abstract：:In recent years, studies have shown that there are many similarities between comets and asteroids. In some cases, it cannot even be determined to which of these groups an object belongs. This is especially true for objects found beyond the main asteroid belt. Because of the lack of comet fragments, more progress has b...

journal_title：Astrobiology

authors： Bosiek K,Hausmann M,Hildenbrand G

更新日期：2016-04-01 00:00:00

abstract：:This experiment was aimed at establishing, for the first time, the survival capability of lichens exposed to space conditions. In particular, the damaging effect of various wavelengths of extraterrestrial solar UV radiation was studied. The lichens used were the bipolar species Rhizocarpon geographicum and Xanthoria e...

journal_title：Astrobiology

authors： Sancho LG,de la Torre R,Horneck G,Ascaso C,de Los Rios A,Pintado A,Wierzchos J,Schuster M

更新日期：2007-06-01 00:00:00

abstract：:Tetrapyrroles are essential to basic biochemical processes such as electron transfer and photosynthesis. However, it is not known whether these evolutionary old molecules have a prebiotic origin. We have serendipitously obtained pyrroles, which are the corresponding monomers, in laboratory experiments that simulated t...

journal_title：Astrobiology

authors： Fox S,Strasdeit H

更新日期：2013-06-01 00:00:00

abstract：: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 Reconnai...

journal_title：Astrobiology

authors： Rennó NO,Backhus R,Cooper C,Flatico JM,Fischer E,Greer LC,Krasowski MJ,Kremic T,Martínez GM,Prokop NF,Sweeney D,Vicente-Retortillo A

更新日期：2019-07-01 00:00:00

abstract：:Evaporation of silica-rich geothermal waters is one of the main abiotic drivers of the formation of silica sinters around hot springs. An important role in sinter structural development is also played by the indigenous microbial communities, which are fossilized and eventually encased in the silica matrix. The combina...

journal_title：Astrobiology

authors： Orange F,Lalonde SV,Konhauser KO

更新日期：2013-02-01 00:00:00

abstract：:The possible meteorite parent body origin of Earth's pregenetic nucleobases is substantiated by the guanine (G), adenine (A), and uracil (U) measured in various meteorites. Cytosine (C) and thymine (T), however, are absent in meteorites, making the emergence of an RNA and later RNA/DNA/protein world problematic. We in...

journal_title：Astrobiology

authors： Pearce BK,Pudritz RE

更新日期：2016-11-01 00:00:00

abstract：:Knowledge and understanding of the martian environment has advanced greatly over the past two decades, beginning with NASA's return to the surface of Mars with the Pathfinder mission and its rover Sojourner in 1997 and continuing today with data being returned by the Curiosity rover. Reduced carbon, however, is yet to...

journal_title：Astrobiology

authors： Harris LV,Hutchinson IB,Ingley R,Marshall CP,Marshall AO,Edwards HG

更新日期：2015-06-01 00:00:00

abstract：:Materials blasted into space from the surface of early Earth may preserve a unique record of our planet's early surface environment. Armstrong et al. (2002) pointed out that such materials, in the form of terrestrial meteorites, may exist on the Moon and be of considerable astrobiological interest if biomarkers from e...

journal_title：Astrobiology

authors： Crawford IA,Baldwin EC,Taylor EA,Bailey JA,Tsembelis K

更新日期：2008-04-01 00:00:00

abstract：:Photosynthesis on Earth can occur in a diversity of organisms in the photosynthetically active radiation (PAR) range of 10 nmol of photons m(-2) s(-1) to 8 mmol of photons m(-2) s(-1). Similar considerations would probably apply to photosynthetic organisms on Earth-like planets (ELPs) in the continuously habitable zon...

journal_title：Astrobiology

authors： Raven JA,Cockell CS

更新日期：2006-08-01 00:00:00

abstract：:We propose a terahertz (far-infrared) circular dichroism-based life-detection technology that may provide a universal and unequivocal spectroscopic signature of living systems regardless of their genesis. We argue that, irrespective of the specifics of their chemistry, all life forms will employ well-structured, chira...

journal_title：Astrobiology

authors： Xu J,Ramian GJ,Galan JF,Savvidis PG,Scopatz AM,Birge RR,Allen SJ,Plaxco KW

更新日期：2003-10-01 00:00:00

abstract：:Understanding the impact of active M dwarf stars on the atmospheric equilibrium and surface conditions of a habitable zone Earth-like planet is key to assessing M dwarf planet habitability. Previous modeling of the impact of electromagnetic (EM) radiation and protons from a single large flare on an Earth-like atmosphe...

journal_title：Astrobiology

authors： Tilley MA,Segura A,Meadows V,Hawley S,Davenport J

更新日期：2019-01-01 00:00:00

abstract：:Recent discoveries about Europa--the probable existence of a sizeable ocean below its ice crust; the detection of hydrated sodium carbonates, among other salts; and the calculation of a net loss of sodium from the subsurface--suggest the existence of an alkaline ocean. Alkaline oceans (nicknamed "soda oceans" in analo...

journal_title：Astrobiology

authors： Kempe S,Kazmierczak J

更新日期：2002-04-01 00:00:00

abstract：UNLABELLED:We developed a prototype instrument called the Standoff Biofinder, which can quickly locate biological material in a 500 cm(2) area from a 2 m standoff distance with a detection time of 0.1 s. All biogenic materials give strong fluorescence signals when excited with UV and visible lasers. In addition, the lu...

journal_title：Astrobiology

authors： Misra AK,Acosta-Maeda TE,Sharma SK,McKay CP,Gasda PJ,Taylor GJ,Lucey PG,Flynn L,Abedin MN,Clegg SM,Wiens R

更新日期：2016-09-01 00:00:00

abstract：:The bicarbonate-buffered anoxic vent waters at Chocolate Pots hot springs in Yellowstone National Park are 51-54°C, pH 5.5-6.0, and are very high in dissolved Fe(II) at 5.8-5.9 mg/L. The aqueous Fe(II) is oxidized by a combination of biotic and abiotic mechanisms and precipitated as primary siliceous nanophase iron ox...

journal_title：Astrobiology

authors： Parenteau MN,Jahnke LL,Farmer JD,Cady SL

更新日期：2014-06-01 00:00:00

abstract：:We launched a cryptoendolithic habitat, made of a gneissic impactite inoculated with Chroococcidiopsis sp., into Earth orbit. After orbiting the Earth for 16 days, the rock entered the Earth's atmosphere and was recovered in Kazakhstan. The heat of entry ablated and heated the rock to a temperature well above the uppe...

journal_title：Astrobiology

authors： Cockell CS,Brack A,Wynn-Williams DD,Baglioni P,Brandstätter F,Demets R,Edwards HG,Gronstal AL,Kurat G,Lee P,Osinski GR,Pearce DA,Pillinger JM,Roten CA,Sancisi-Frey S

更新日期：2007-02-01 00:00:00

abstract：:We review the in situ geochronology experiments conducted by the Mars Science Laboratory mission's Curiosity rover to understand when the Gale Crater rocks formed, underwent alteration, and became exposed to cosmogenic radiation. These experiments determined that the detrital minerals in the sedimentary rocks of Gale ...

journal_title：Astrobiology

authors： Cohen BA,Malespin CA,Farley KA,Martin PE,Cho Y,Mahaffy PR

更新日期：2019-11-01 00:00:00