scholarly journals Effect of Nontronite Smectite Clay on the Chemical Evolution of Several Organic Molecules under Simulated Martian Surface Ultraviolet Radiation Conditions

Astrobiology ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 221-237 ◽  
Author(s):  
Olivier Poch ◽  
Maguy Jaber ◽  
Fabien Stalport ◽  
Sophie Nowak ◽  
Thomas Georgelin ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Chemical Evolution ◽  
Organic Molecules ◽  
Martian Surface ◽  
Smectite Clay ◽  
Radiation Conditions

scholarly journals Adaptation to local ultraviolet radiation conditions among neighbouring Daphnia populations

2010 ◽  
Vol 278 (1710) ◽  
pp. 1306-1313 ◽  
Author(s):  
Brooks E. Miner ◽  
Benjamin Kerr
Keyword(s):  
Ultraviolet Radiation ◽  
Environmental Variables ◽  
Population Genetic ◽  
Phenotypic Diversity ◽  
Experimental Population ◽  
Phenotypic Divergence ◽  
Trade Offs ◽  
Adaptive Processes ◽  
Subdivided Populations ◽  
Radiation Conditions

Understanding the historical processes that generated current patterns of phenotypic diversity in nature is particularly challenging in subdivided populations. Populations often exhibit heritable genetic differences that correlate with environmental variables, but the non-independence among neighbouring populations complicates statistical inference of adaptation. To understand the relative influence of adaptive and non-adaptive processes in generating phenotypes requires joint evaluation of genetic and phenotypic divergence in an integrated and statistically appropriate analysis. We investigated phenotypic divergence, population-genetic structure and potential fitness trade-offs in populations of Daphnia melanica inhabiting neighbouring subalpine ponds of widely differing transparency to ultraviolet radiation (UVR). Using a combination of experimental, population-genetic and statistical techniques, we separated the effects of shared population ancestry and environmental variables in predicting phenotypic divergence among populations. We found that native water transparency significantly predicted divergence in phenotypes among populations even after accounting for significant population structure. This result demonstrates that environmental factors such as UVR can at least partially account for phenotypic divergence. However, a lack of evidence for a hypothesized trade-off between UVR tolerance and growth rates in the absence of UVR prevents us from ruling out the possibility that non-adaptive processes are partially responsible for phenotypic differentiation in this system.

A discussion on infared astronomy - On the chemistry of Jupiter's upper atmosphere

1969 ◽  
Vol 264 (1150) ◽  
pp. 151-151
Keyword(s):  
Ultraviolet Radiation ◽  
Cross Section ◽  
Infrared Radiation ◽  
Organic Molecules ◽  
General Procedure ◽  
Analytical Approximation ◽  
Upper Atmosphere ◽  
Rapid Rise ◽  
Absorption Bands ◽  
Jovian Atmosphere

The infrared opacity of Jupiter’s upper atmosphere will be influenced by line blanketing resulting from strong absorption bands of ammonia and organic molecules. In order to calculate these effects eventually, we conduct a first investigation into the ion-molecule chemistry of the upper Jovian atmosphere. Experimental results show that intense ultraviolet radiation reacts with the constituents of the Jovian atmosphere to produce C2H4> ^2^65 a, and higher polymers. The general procedure for calculating both equilibrium and non-equilibrium abundances of these products is formulated and applied to the case of the surface passage of a satellite shadow. A specific example is made of ethylene, for which an analytical approximation gives 10 (to power of 10) molecules in an atmospheric column of 1 cm2 cross-section after a very rapid rise to equilibrium. Such a concentration of ethylene does not substantially affect the infrared radiation in the shadow.

Analysis of organic compounds in Mars soil analog samples using SuperCam-Raman of Mars2020

2021 ◽  
Author(s):  
Imanol Torre-Fdez ◽  
Teresa Fornaro ◽  
Julene Aramendia ◽  
Ann Ollila ◽  
Keyword(s):  
Organic Compounds ◽  
Clay Mineral ◽  
Near Infrared ◽  
Organic Molecules ◽  
Spot Size ◽  
Martian Surface ◽  
Long Distance ◽  
Commercial Laboratory ◽  
Pure Compounds

<p>One of the main objectives of the Perseverance rover is to find signs of ancient life in the Martian surface, seeking biosignatures and signs of past habitable conditions. This could be achieved with the finding of organic compounds related to life. Raman spectroscopy is among the techniques that the rover is capable of performing, which is able to detect and discern organic molecules. Perseverance carries in its payload two instruments that are able to use this technique, SuperCam for remote sensing and SHERLOC for proximity measurements. SuperCam is a long-distance instrument capable of performing several techniques (Raman, LIBS, luminescence, VISIR, microphone) in order to assess the chemical and molecular composition of rocks (mineral phases and organic molecules) from a distance up to 7 m. Therefore, it could detect organics, or traces of them, from a distance before the rover gets closer.</p><p>In this work, a set of Mars soil analog samples were analyzed using the Flying Model-Body Unit / Engineering Qualification Model-Mast Unit (FM-BU/EQM-MU) setup of SuperCam. Specifically, the samples were prepared in the laboratory by adsorbing adenosine 5’-monophosphate, L-glutamic acid, L-phenylalanine, and phthalic acid with different known concentrations (5 wt%, 1 wt% and 0.1 wt%) on the clay mineral montmorillonite doped with 1 wt% of Mg-perchlorate. The preparation and characterization of those samples can be found in literature [1]. The analyses were carried out at a 2 m distance from the targets, with a laser spot size of around 300 µm at that distance. SuperCam showed excellent results for the pure compounds, before adsorption on the clay mineral. At 5 wt% concentration, the Raman signals of the organics were barely visible and at 1 wt% they were no longer visible. This fact means that if the laser of SuperCam hits an organic “hotspot” in a rock from a distance, it will be able to detect it as long as it has a concentration around 5 wt% or greater in the analyzed area, allowing SHERLOC to do further contact analysis afterwards. In addition, the SuperCam results were compared with those obtained with a commercial laboratory instrument (Renishaw inVia), obtaining the same main signals and only missing some minor secondary bands.</p><p>[1] T. Fornaro, J. R. Brucato, G. Poggiali, M. A. Corazzi, M. Biczysko, M. Jaber, D. I. Foustoukos, R. M. Hazen, A. Steele, UV irradiation and Near Infrared characterization of laboratory Mars soil analog samples, Frontiers in Astronomy and Space Sciences, 2020, 7, 1-20</p>

Investigating the Photostability of Carboxylic Acids Exposed to Mars Surface Ultraviolet Radiation Conditions

Astrobiology ◽  
2009 ◽  
Vol 9 (6) ◽  
pp. 543-549 ◽  
Author(s):  
F. Stalport ◽  
P. Coll ◽  
C. Szopa ◽  
H. Cottin ◽  
F. Raulin
Keyword(s):  
Ultraviolet Radiation ◽  
Carboxylic Acids ◽  
Radiation Conditions

Photochemical stability of biomolecules in the experiments modelling Martian surface conditions

2005 ◽  
Vol 4 (1) ◽  
pp. 93-96 ◽  
Author(s):  
N.B. Gontareva
Keyword(s):  
Organic Molecules ◽  
Prebiotic Synthesis ◽  
Reaction Products ◽  
Nucleic Acid Bases ◽  
Martian Surface ◽  
Surface Conditions ◽  
Solvent Free Conditions ◽  
Research Task ◽  
Extraterrestrial Material ◽  
Organic Acids And Sugars

Life has probably existed on Earth for about 3.5 billion years and ever since people could wonder, they have tried to understand its origins. It is thought that organisms as complex as bacteria emerged within 0.5–1 billion years. Organic molecules, such as amino acids, organic acids and sugars have been observed in material from extraterrestrial sources in the solar system. But, to confirm the possibility of nucleic acid bases also being synthesized under these conditions, we have replicated the synthesis of monophosphates as dry pellets (5′-monophosphates, the predominant reaction products) under simulated Martian conditions. Our research task was to find out whether the main organic substances were able to survive in the absence of water. This reaction must proceed under solvent-free conditions and incident short ultraviolet radiation (UVC) in a vacuum. After 5 months of reaction time monophosphates could be identified in detectable quantities. These experiments utilized basalt and limonite as protectors and successfully shielded the products from decomposition by UVC. Our team has obtained more results concerning prebiotic synthesis of polypeptides and nucleotides in the presence of meteorite dust; these are the same kind of experiment, but using different extraterrestrial material.

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