Prebiotic Organic Globules

Analogs of organic globules observed in carbonaceous chondrite meteorites and in interplanetary dust particles and of rod to spherical structures observed in terrestrial archean microstructures have been synthesized in our experiments conducted with proton irradiation on a mixture of simple inorganic constituants, CO, N2 and H2O. Our analyses of these laboratory organic globules show that the proton irradiation residue contains proteinous and non-proteinous amino acid precursors. On the basis of morphology, of hydrothermal and mineral environment, we suggest that the meteoritic organic globules and the archean carbon microstructures could be composed of amino acid precursors

Organic Analysis of Peridotite Rocks from the Ashadze and Logatchev Hydrothermal Sites

This article presents an experimental analysis of the organic content of two serpentinized peridotite rocks of the terrestrial upper mantle. The samples have been dredged on the floor of the Ashadze and Logatchev hydrothermal sites on the Mid-Atlantic Ridge. In this preliminary analysis, amino acids and long chain n-alkanes are identified. They are most probably of biological/microbial origin. Some peaks remain unidentified

Prebiotic Organic Microstructures

Micro- and sub-micrometer spheres, tubules and fiber-filament soft structures have been synthesized in our experiments conducted with 3 MeV proton irradiations of a mixture of simple inorganic constituents, CO, N2 and H2O. We analysed the irradiation products, with scanning electron microscopy (SEM) and atomic force microscopy (AFM). These laboratory organic structures produced wide variety of proteinous and non-proteinous amino acids after HCl hydrolysis. The enantiomer analysis for D-, L- alanine confirmed that the amino acids were abiotically synthesized during the laboratory experiment. Considering hydrothermal activity, the presence of CO2 and H2, of a ferromagnesian silicate mineral environment, of an Earth magnetic field which was much less intense during Archean times than nowadays and consequently of a proton excitation source which was much more abundant, we propose that our laboratory organic microstructures might be synthesized during Archean times. We show similarities in morphology and in formation with some terrestrial Archean microstructures and we suggest that some of the observed Archean carbon spherical and filamentous microstructures might be composed of abiogenic organic molecules. We further propose a search for such prebiotic organic signatures on Mars. This article has been posted on Nature precedings on 21 July 2010 [1]. Extinct radionuclides as source of excitation have been replaced by cosmic radiations which were much more intense 3.5 Ga ago because of a much less intense Earth magnetic field. The new version of the article has been presented at the ORIGINS conference in Montpellier in july 2011 [2] and has since been published in Origins of Life and Evolution of Biospheres 42 (4) 307-316, 2012. 
DOI: 10.1007/s11084-012-9290-5 

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Follow the High Subcritical Water

The expression “follow the water” is used to recognize inside the universe, life as it exists on Earth. It is shown here that the expression “follow the high subcritical water” can be used to recognize the components of life that formed prior to the emergence of life. It is also shown that this particular water leaves signatures inside rocks that are produced during high subcritical water–rock interactions. These signatures are ferric minerals, which are currently explained by the presence of microorganisms. The consideration of water in the high subcritical domain may lead to postpone the date of the existence of FeII-oxidizing and O2-producing microorganisms, and consequently the date of the appearance of oxygen in the atmosphere. Alkaline water at pH ~9.5 to 14 and in the specific domain of temperature ~300–350 °C, pressure ~10–25 MPa, and density ~700–600 kg/m3, allows us to understand the formation of silica and ferric minerals, and the synformation of components of life in anoxic geological terrains such as the banded iron formations on early Earth and extraterrestrial objects such as Enceladus. The high subcritical water lets appear the continuity between rocks and life, which is conceptualized by the word “geobiotropy”

High subcritical water-rock interaction for the formation of ferric minerals, in the absence of oxygen, UV light and microorganisms

The formation of ferric minerals on the anoxic early Earth is usually explained with the action of microorganisms or UV light in acidic conditions. Results show that amorphous and crystalline ferric oxides and silicates can form in the absence of oxygen, microorganisms and UV light, when rocks, located in the upper crust of the Earth until ca 1 km depth, contain ferrous silicates which interact with water called high subcritical, at 300-350 °C and 10-25 MPa. This conclusion is established following the analyses of Eh-pH diagrams for the Fe-H2O system and solubility diagrams for quartz and amorphous silica. It is shown that water below the critical point and not above can lead to the formation of ferric iron in geological terrains on Earth and extraterrestrial objects where anoxic alkaline high subcritical water reacts with rocks containing ferrous silicates

Etude spectrochimique de la glycine et de quelques molécules connexes. Analyse rotationnelle et observations du milieu interstellaire.

The purpose of this research is to observe the chemical composition of galactic molecular clouds with the goal to gain informations on the origin of Life. The most substantial project concerns the amino acid glycine. The rotational analysis of this prebiotic molecule is conducted in Monash University, Australia. Spectra are difficult to assign. At the temperature of the experiment, 200°C, the population is distributed over a large number of vibrational and rotational levels belonging to several conformers of this ten atoms molecule and to its decomposition products. Also, the microwave spectrometer based on Stark modulation of the absorption lines is not appropriate. Despite difficulties, the identification of lines observed between 26 GHz and 63 GHz could lead to the determination of the rotational parameters and to the components of the dipole moment. The determination of the hyperfin structure, linked to the electrical quadrupole of the nitrogen nucleus, allows to conclude that the studied conformer hosts an hydrogen intramolecular bond. Results are in good agreement with those published later by other laboratories. Radioastronomical observations are performed at Parkes/Australia, Kitt-Peak/Arizona and Onsala/Sweden, in the direction of Orion A and Sagittarius B2 and also 7 other clouds. Six transitions between 22.7 and 83.4 GHz are searched. An upper limit for the column density of glycine molecules along the line of sight is calculated to be 10¹² cm⁻² up to 10¹⁴ cm⁻². Glycine might be less abundant than ethanol and ethyl cyanide. New transitions of methanol and methyl cyanide are detected and equations of radiative transfer and statistical equilibrium are written for an asymmetric top molecule.L'objectif des travaux est l'observation de la composition chimique de nuages moléculaires de la Galaxie afin d'apporter une contribution à la connaissance de l'origine de la vie. Le projet principal concerne l'acide aminé glycine. L'analyse rotationnelle de cette molécule prébiotique est effectuée à Monash University, Australie. Les spectres sont complexes. De nombreux niveaux de vibration et de rotation des conformères de cette molécule à 10 atomes et des molécules issues de sa décomposition, sont peuplés à la température de l'expérience, 200°C et de plus le spectromètre microonde utilisé, à modulation d'absorption par effet Stark, n'est pas approprié. En dépit des difficultés, l'identification de transitions entre 26 GHz et 63 GHz a permis la détermination des paramètres rotationnels et des composantes du moment dipolaire. La structure hyperfine associée au quadripôle électrique du noyau d'azote permet de conclure à une liaison hydrogène intramoléculaire pour le conformère étudié. Les résultats sont en bon accord avec ceux publiés ultérieurement par d'autres laboratoires. Les observations radioastronomiques conduites à Parkes/Australie, Kitt-Peak/Arizona et Onsala/Suède sont effectuées dans la direction de Orion A et de Sagittarius B2, ainsi que de 7 autres nuages. Six transitions entre 22.7 GHz et 83.4 GHz sont recherchées. Une valeur limite supérieure pour la densité de molécules le long de la ligne de vue est calculée : 10¹² cm⁻² à 10¹⁴ cm⁻². La glycine serait moins abondante que l'éthanol et le cyanure d'éthyle. Des transitions nouvelles du méthanol et du cyanure de méthyle sont détectées et un programme d'excitation moléculaire est écrit

Réaction de l’azote activé avec le tétrachlorure de tellure

L’action de l’azote activé sur le tétrachlorure de tellure donne lieu aux émissions suivantes : a