Prebiotic glycosylation of uracil with electron-donating substituents.

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：:The Planetary Society's Phobos Living Interplanetary Flight Experiment (Phobos LIFE) flew in the sample return capsule of the Russian Federal Space Agency's Phobos Grunt mission and was to have been a test of one aspect of the hypothesis that life can move between nearby planets within ejected rocks. Although the Phob...

journal_title：Astrobiology

authors： Betts BH,Warmflash D,Fraze RE,Friedman L,Vorobyova E,Lilburn TG,Smith A,Rettberg P,Jönsson KI,Ciftcioglu N,Fox GE,Svitek T,Kirschvinck JL,Moeller R,Wassmann M,Berger T

更新日期：2019-09-01 00:00:00

abstract：:Cyanobacteria and similar organisms produced most of the oxygen found in Earth's atmosphere, which implies that early photosynthetic organisms would have lived in an atmosphere that was rich in CO2 and poor in O2. We investigated the tolerance of several cyanobacteria to very high (>20 kPa) concentrations of atmospher...

journal_title：Astrobiology

authors： Thomas DJ,Sullivan SL,Price AL,Zimmerman SM

更新日期：2005-02-01 00:00:00

abstract：:The objective of the 2009 Mars Science Laboratory (MSL), which is planned to follow the Mars Exploration Rovers and the Phoenix lander to the surface of Mars, is to explore and assess quantitatively a site on Mars as a potential habitat for present or past life. Specific goals include an assessment of the past or pres...

journal_title：Astrobiology

authors： ten Kate IL,Canham JS,Conrad PG,Errigo T,Katz I,Mahaffy PR

更新日期：2008-06-01 00:00:00

abstract：:Recent measurements of methane (CH4) by the Mars Science Laboratory (MSL) now confront us with robust data that demand interpretation. Thus far, the MSL data have revealed a baseline level of CH4 (∼0.4 parts per billion by volume [ppbv]), with seasonal variations, as well as greatly enhanced spikes of CH4 with peak ab...

journal_title：Astrobiology

authors： Yung YL,Chen P,Nealson K,Atreya S,Beckett P,Blank JG,Ehlmann B,Eiler J,Etiope G,Ferry JG,Forget F,Gao P,Hu R,Kleinböhl A,Klusman R,Lefèvre F,Miller C,Mischna M,Mumma M,Newman S,Oehler D,Okumura M,Oremland R,

更新日期：2018-10-01 00:00:00

abstract：:Life-detection instruments on future Mars missions may use surfactant solutions to extract organic matter from samples of martian rocks. The thermal and radiation environments of space and Mars are capable of degrading these solutions, thereby reducing their ability to dissolve organic species. Successful extraction a...

journal_title：Astrobiology

authors： Court RW,Sims MR,Cullen DC,Sephton MA

更新日期：2014-09-01 00:00:00

abstract：:This review of material relevant to the Conference on Biosignature Preservation and Detection in Mars Analog Environments summarizes the meeting materials and discussions and is further expanded upon by detailed references to the published literature. From this diverse source material, there is a detailed discussion o...

journal_title：Astrobiology

authors： Hays LE,Graham HV,Des Marais DJ,Hausrath EM,Horgan B,McCollom TM,Parenteau MN,Potter-McIntyre SL,Williams AJ,Lynch KL

更新日期：2017-04-01 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：:Like all low- and moderate-mass stars, the Sun will burn as a red giant during its later evolution, generating of solar luminosities for some tens of millions of years. During this post-main sequence phase, the habitable (i.e., liquid water) thermal zone of our Solar System will lie in the region where Triton, Pluto-C...

journal_title：Astrobiology

authors： Stern SA

更新日期：2003-07-01 00:00:00

abstract：UNLABELLED:The search for indisputable traces of life in Archean cherts is of prime importance. However, their great age and metamorphic history pose constraints on the study of molecular biomarkers. We propose a quantitative criterion to document the thermal maturity of organic matter in rocks in general, and Archean ...

journal_title：Astrobiology

authors： Delarue F,Rouzaud JN,Derenne S,Bourbin M,Westall F,Kremer B,Sugitani K,Deldicque D,Robert F

更新日期：2016-06-01 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：:Polymeric compounds similar to oligonucleotides are relevant to the origin of life and particularly to the concept of an RNA world. Although short oligomers of RNA can be synthesized nonenzymatically under laboratory conditions by second-order reactions in concentrated solutions, there is no consensus on how these pol...

journal_title：Astrobiology

authors： Kanavarioti A,Monnard PA,Deamer DW

更新日期：2001-10-01 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：: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：:Properties of avenues of transformation and their mutualism with forms of organization in dynamic systems are essential for understanding the evolution of prebiotic order. We have analyzed competition between two avenues of transformation in an A↔B system, using the simulation approach called BiADA (Biotic Abstract Du...

journal_title：Astrobiology

authors： Popa R,Cimpoiasu VM

更新日期：2013-05-01 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：:Chloride-bearing deposits and phyllosilicates-bearing units are widely distributed in the southern highlands of Mars, but these phases are rarely found together in fluviolacustrine environments. The study of the coexistence of these minerals can provide important insights into geochemistry, water activity, and ultimat...

journal_title：Astrobiology

authors： Huang 黄俊 J,Salvatore MR,Edwards CS,Harris RL,Christensen PR

更新日期：2018-08-01 00:00:00

abstract：:Two major parameters influencing the survival of Bacillus subtilis spores in space and on bodies within the Solar System are UV radiation and vacuum, both of which induce inactivating damage to DNA. To date, however, spore survival and DNA photochemistry have been explored only at the extremes of Earth-normal atmosphe...

journal_title：Astrobiology

authors： Nicholson WL,Setlow B,Setlow P

更新日期：2002-01-01 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：:Rover missions to the rocky bodies of the Solar System and especially to Mars require lightweight, portable instruments that use minimal power, require no sample preparation, and provide suitably diagnostic mineralogical information to an Earth-based exploration team. Short-wave infrared (SWIR) spectroscopic instrumen...

journal_title：Astrobiology

authors： Brown A,Walter M,Cudahy T

更新日期：2004-10-01 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：:Water, vital for life, not only maintains the integrity of structural and metabolic biomolecules, it also transports them in solution or colloidal suspension. Any flow of water through a dormant or fossilized microbial community elutes molecules that are potentially recognizable as biomarkers. We hypothesize that the ...

journal_title：Astrobiology

authors： Wynn-Williams DD,Cabrol NA,Grin EA,Haberle RM,Stoker CR

更新日期：2001-07-01 00:00:00

abstract：:Stromatolite structures in Early Archean carbonate deposits form an important clue for the existence of life in the earliest part of Earth's history. Since Mars is thought to have had similar environmental conditions early in its history, the question arises as to whether such stromatolite structures also evolved ther...

journal_title：Astrobiology

authors： Rividi N,van Zuilen M,Philippot P,Ménez B,Godard G,Poidatz E

更新日期：2010-04-01 00:00:00

abstract：:The thermal springs Trollosen and Fisosen, located on the High Arctic archipelago Svalbard, discharge saline groundwaters rich in hydrogen sulfide and ammonium through a thick layer of permafrost. Large amounts of biomass that consist of filamentous microorganisms containing sulfur granules, as analyzed with energy di...

journal_title：Astrobiology

authors： Reigstad LJ,Jorgensen SL,Lauritzen SE,Schleper C,Urich T

更新日期：2011-09-01 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：:The aim of this study was to analyze tolerance to heavy ions in desiccated animals of the eutardigrade Richtersius coronifer and the bdelloid rotifer Mniobia russeola within the STARLIFE project. Both species were exposed to iron (Fe) and helium (He) ions at the Heavy Ion Medical Accelerator in Chiba (HIMAC) in Chiba,...

journal_title：Astrobiology

authors： Jönsson KI,Wojcik A

更新日期：2017-02-01 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：: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：UNLABELLED:Fluid inclusions trapped in ancient halite can contain a community of halophilic prokaryotes and eukaryotes that inhabited the surface brines from which the halite formed. Long-term survival of bacteria and archaea and preservation of DNA have been reported from halite, but little is known about the distribu...

journal_title：Astrobiology

authors： Wang J,Lowenstein TK,Fang X

更新日期：2016-06-01 00:00:00

abstract：:A continuing challenge for scientists is to keep K-12 teachers informed about new scientific developments. Over the past few years, this challenge has increased as new research findings have come from the field of astrobiology. In addition to trying to keep abreast of these new discoveries, K-12 teachers must also fac...

journal_title：Astrobiology

authors： Prather EE,Slater TF

更新日期：2002-07-01 00:00:00