Biogenesis and early life on Earth and Europa: favored by an alkaline ocean?

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

abstract：:The hyperarid core of the Atacama Desert is one of the driest and most inhospitable places on Earth, where life is most commonly found in the interior of rocks (i.e., endolithic habitats). Due to the extreme dryness, microbial activity in these habitats is expected to be low; however, the rate of carbon cycling within...

journal_title：Astrobiology

authors： Ziolkowski LA,Wierzchos J,Davila AF,Slater GF

更新日期：2013-07-01 00:00:00

abstract：:Jökulhlaups are terrestrial catastrophic outfloods, often triggered by subglacial volcanic eruptions. Similar volcano-ice interactions were likely important on Mars where magma/lava may have interacted with the planet's cryosphere to produce catastrophic floods. As a potential analogue to sediments deposited during ma...

journal_title：Astrobiology

authors： Warner NH,Farmer JD

更新日期：2010-06-01 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：: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：: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

abstract：:Over the past few years a series of searches for interstellar radio beacons have taken place using the Parkes radio telescope. Here we report hitherto unpublished results from a search for optical beacons from 60 solar-type stars using the Perth-Lowell telescope. We discuss the significance of the null results from th...

journal_title：Astrobiology

authors： Blair DG,Zadnik MG

更新日期：2002-10-01 00:00:00

abstract：:Viability rates were determined for microbial populations of Escherichia coli and Deinococcus radiodurans under the environmental stresses of low temperature (-35 degrees C), low-pressure conditions (83.3 kPa), and ultraviolet (UV) irradiation (37 W/m(2)). During the stress tests the organisms were suspended in saltwa...

journal_title：Astrobiology

authors： Diaz B,Schulze-Makuch D

更新日期：2006-04-01 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：: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：:Granitoids are silicic rocks that make up the majority of the continental crust, but different models arise for the origins of these rocks. One classification scheme defines different granitoid types on the basis of materials involved in the melting/crystallization process. In this end-member case, granitoids may be d...

journal_title：Astrobiology

authors： Trail D,Tailby ND,Sochko M,Ackerson MR

更新日期：2015-07-01 00:00:00

abstract：:During three low-altitude (99, 66, 66 km) flybys through the Enceladus plume in 2010 and 2011, Cassini's ion neutral mass spectrometer (INMS) made its first high spatial resolution measurements of the plume's gas density and distribution, detecting in situ the individual gas jets within the broad plume. Since those fl...

journal_title：Astrobiology

authors： Teolis BD,Perry ME,Hansen CJ,Waite JH,Porco CC,Spencer JR,Howett CJA

更新日期：2017-09-01 00:00:00

abstract：:Mars Odyssey has given strong evidence for the existence of water in the upper martian surface at equatorial latitudes. The water content, which corresponds to the hydrogen in the soil, can regionally reach values up to about 15%. This water is mainly in the form of structurally and partially irreversibly bound "cryst...

journal_title：Astrobiology

authors： Möhlmann D

更新日期：2005-12-01 00:00:00

abstract：:We investigate a new mechanism for producing oxidants, especially hydrogen peroxide (H2O2), on Mars. Large-scale electrostatic fields generated by charged sand and dust in the martian dust devils and storms, as well as during normal saltation, can induce chemical changes near and above the surface of Mars. The most dr...

journal_title：Astrobiology

authors： Atreya SK,Wong AS,Renno NO,Farrell WM,Delory GT,Sentman DD,Cummer SA,Marshall JR,Rafkin SC,Catling DC

更新日期：2006-06-01 00:00:00

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：:The emergence of chirality in enantioselective autocatalysis for compounds unable to transform according to the Frank-like reaction network is discussed with respect to the controversial limited enantioselectivity (LES) model composed of coupled enantioselective and non-enantioselective autocatalyses. The LES model ca...

journal_title：Astrobiology

authors： Ribó JM,Crusats J,El-Hachemi Z,Moyano A,Blanco C,Hochberg D

更新日期：2013-02-01 00:00:00

abstract：:The search for organic biosignatures on Mars will depend on finding material protected from the destructive ambient radiation. Solar ultraviolet can induce photochemical degradation of organic compounds, but certain clays have been shown to preserve organic material. We examine how the SHERLOC instrument on the upcomi...

journal_title：Astrobiology

authors： Razzell Hollis J,Fornaro T,Rapin W,Wade J,Vicente-Retortillo Á,Steele A,Bhartia R,Beegle LW

更新日期：2021-01-25 00:00:00

abstract：:Bacterial endospores in the genus Bacillus are considered good models for studying interplanetary transfer of microbes by natural or human processes. Although spore survival during transfer itself has been the subject of considerable study, the fate of spores in extraterrestrial environments has received less attentio...

journal_title：Astrobiology

authors： Nicholson WL,Schuerger AC

更新日期：2005-08-01 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：: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：:The cloud layer has been hypothesized to be the most habitable region of Venus. In the lower clouds, both temperature and pressure fall within bounds that support reproduction of microbial life on Earth, although the water activity of the sulfuric acid cloud droplets makes the clouds uninhabitable to known life. In th...

journal_title：Astrobiology

authors： Cockell CS,Higgins PM,Johnstone AA

更新日期：2021-01-19 00:00:00

abstract：:Raman spectroscopy is being adopted as a nondestructive instrumentation for the robotic exploration of Mars to search for traces of life in the geological record. Here, miniaturized Raman spectrometers of two different types equipped with 532 and 785 nm lasers for excitation, respectively, were compared for the detect...

journal_title：Astrobiology

authors： Vítek P,Jehlička J,Edwards HG,Hutchinson I,Ascaso C,Wierzchos J

更新日期：2012-12-01 00:00:00

abstract：:The NASA Astrobiology Roadmap provides guidance for research and technology development across the NASA enterprises that encompass the space, Earth, and biological sciences. The ongoing development of astrobiology roadmaps embodies the contributions of diverse scientists and technologists from government, universities...

journal_title：Astrobiology

authors： Des Marais DJ,Allamandola LJ,Benner SA,Boss AP,Deamer D,Falkowski PG,Farmer JD,Hedges SB,Jakosky BM,Knoll AH,Liskowsky DR,Meadows VS,Meyer MA,Pilcher CB,Nealson KH,Spormann AM,Trent JD,Turner WW,Woolf NJ,Yorke HW

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：: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：: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：: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 multidiscipli...

journal_title：Astrobiology

authors： Brady AL,Kobs Nawotniak SE,Hughes SS,Payler SJ,Stevens AH,Cockell CS,Elphic RC,Sehlke A,Haberle CW,Slater GF,Lim DSS

更新日期：2019-03-01 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：UNLABELLED:In this paper, percolation theory is employed to place tentative bounds on the probability p of interstellar travel and the emergence of a civilization (or panspermia) that colonizes the entire Galaxy. The ensuing ramifications with regard to the Fermi paradox are also explored. In particular, it is suggeste...

journal_title：Astrobiology

authors： Lingam M

更新日期：2016-06-01 00:00:00

abstract：:Ultraviolet (UV) irradiation on the surface of Mars is an important factor that affects the survivability of microorganisms on Mars. The possibility of martian brines made from Fe2(SO4)3, MnSO4, and MgSO4 salts providing a habitable niche on Mars via attenuation of UV radiation was investigated on the bacteria Bacillu...

journal_title：Astrobiology

authors： Godin PJ,Schuerger AC,Moores JE

更新日期：2020-11-25 00:00:00