The HADES mission concept - astrobiological survey of Jupiter's icy moon Europa

The HADES Europa mission concept aims to provide a framework for an astrobiological in-depth investigation of the Jupiter moon Europa, relying on existing technologies and feasibility. This mission study proposes a system consisting of an orbiter, lander and cryobot as a platform for detailed exploration of Europa. While the orbiter will investigate the presence of a liquid ocean and characterize Europa's internal structure, the lander will survey local dynamics of the ice layer and the surface environment. The lander releases a cryobot, that melts into the ice, will sample the pristine subsurface and is expected to provide data on organic and gaseous content and putative bio-signatures. In summary, we present the scientific objectives for an astrobiological investigation of Europa, resulting in a mission concept with a detailed evaluation of scientific instrumentation, mission sequences, basic design of the spacecraft, technology needs and cost estimation

The HADES mission concept – Astrobiological survey of Jupiter's icy moon Europa

The HADES Europa mission concept aims to provide a framework for an astrobiological in-depth investigation of the Jupiter moon Europa, relying on existing technologies and feasibility. This mission study proposes a system consisting of an orbiter, lander and cryobot as a platform for detailed exploration of Europa. While the orbiter will investigate the presence of a liquid ocean and characterize Europa's internal structure, the lander will survey local dynamics of the ice layer and the surface environment. The lander releases a cryobot, that melts into the ice, will sample the pristine subsurface and is expected to provide data on organic and gaseous content and putative bio-signatures. In summary, we present the scientific objectives for an astrobiological investigation of Europa, resulting in a mission concept with a detailed evaluation of scientific instrumentation, mission sequences, basic design of the spacecraft, technology needs and cost estimations

Modern and ancient micrometeorites: Experimental and numerical studies

Micrometeorites are sub-millimetric extraterrestrial samples, which dominate the flux of extraterrestrial matter entering the Earth atmosphere. Every micrometeorite is altered by the interaction with the atmosphere. However, they can be found embedded in larger meteorites, in which case they are called microxenoliths. Microxenoliths are ancient micrometeorites, and they allow the study of past epochs of the Solar System, not accessible by studying micrometeorites. New microxenoliths have been discovered and studied in H chondrites and in the carbonaceous chondrite Isheyevo. Many different techniques (scanning and transmission electron microscopy, Raman spectroscopy, mass spectrometry) have been applied to characterize them. Also, numerical simulations have been performed to investigate their origin and the effects they suffer during the passage through the Earth atmosphere.Les micrométéorites, échantillons extraterrestres de taille submillimétrique, dominent le flux de matière extraterrestre qui entre dans l'atmosphère terrestre. Toute micrométéorite est inévitablement altérée par son passage atmosphérique. Mais elles peuvent être trouvées enchâssées dans des météorites plus grandes, sous forme de microxénolithes. Les microxénolithes sont des micrométéorites anciennes, ils permettent d'étudier des époques passées de l'histoire du Système Solaire, pas accessibles par les micrométéorites. Des nouveaux microxénolithes ont été découverts et étudiés dans les chondrites H et dans la chondrite carbonée Isheyevo. Plusieurs techniques expérimentales (microscopie électronique à balayage et à transmission, spectroscopie Raman, spectrométrie de masse) ont été utilisées pour les caractériser, et des simulations numériques ont été réalisées pour étudier leur origine et les effets qu'ils subissent lors de leur passage dans l'atmosphère de la Terre

Thermal History of Micrometeoroids during the atmospheric entry

INTRODUCTION Micrometeoroids (MMs) represent the largest mass flux of extraterrestrial matter to the present-day Earth (Love S. G. and Brownlee D. E. 1993 Icarus, 89, 26) and their flux was probably even larger during the heavy bombardment period, betweem 4 and 3.8 Gy ago. Micrometeoroids may have been the dominant source of organic carbon and may have contributed significantly to the delivery of water on the primitive Earth (Gounelle M. et al. 2005 GCA, 69, 3431). Upon atmospheric entry micrometeoroids suffer a frictional heating because of which their surface temperature rapidly reaches values as high as 1000 °K or greater. At these temperatures organic compounds evaporate or decompose. Most of the current models pertaining this topic assume the temperature of the particle as homogeneous through the whole volume. However, micrometeorites collected on the Earth’s surface show evidences that thermal gradients developed during the atmospheric passage (Genge M. J. et al. 1997 GCA, 61, 5149). The existence of these gradients may allow the survival of organic species in the interior of micrometeorites

On the prospective detection of polyoxymethylene in comet 67P/Churyumov–Gerasimenko with the COSIMA instrument onboard Rosetta

The presence of polyoxymethylene (POM) in cometary grains has been debated years ago. Although never proven, its presence can not be excluded. Rosetta, the ESA mission to comet 67P/Churyumov–Gerasimenko, may answer this question. On board the spacecraft, COSIMA (COmetary Secondary Ion Mass Analyzer) will analyze the grains ejected from the nucleus using a Time Of Flight Secondary Ion Mass Spectrometer (TOF-SIMS). In this paper we report the extent to which COSIMA will be able to detect POM if this compound is present on cometary grains. We have analyzed two kinds of POM polymers with a laboratory model of COSIMA. Positive mass spectra display alternating sequence of peaks with a separation of 30.011 Da between 1 and 600 Da related to formaldehyde and its oligomers but also to the fragmentation of these oligomers. The separation of 30.011 Da of numbers peaks, corresponding to the fragmentation into H2CO is characteristic of POM and we show that it could be highlight by mathematical treatment. POM lifetime on COSIMA targets have also been studied as POM is thermally instable. It can be concluded that the cometary grains analysis have to be planned not too long after their collection in order to maximize the chances to detect POM. This work was supported by the Centre National d'Etudes Spatiales (CNES)

Interstellar and interplanetary carbonaceous solids in the laboratory

International audienceThe interstellar medium (ISM) is a physico-chemical laboratory where extreme conditions are encountered and whereparticular environmental parameters (e.g., density, reactant nature, radiation, temperature, time scales) define the compositionof matter. With present observational possibilities, the fundamental question regarding the possible link betweenISM and solar system samples can be addressed by astrophysicists, planetologists, and cosmochemists. This article focuseson observations of diffuse ISM and dust components of molecular clouds, setting constraints on the composition oforganic solids and large molecules associated with matter cycling in the Galaxy. This study aims at drawing somecommonalities and differences between the materials found in the Solar System and those found in interstellar dust

TARDBP (TDP-43) sequence analysis in patients with familial and sporadic ALS: identification of two novel mutations.

BACKGROUND AND PURPOSE: Increasing evidence suggests a direct role of the TAR DNA-binding protein 43 (TDP-43) in neurodegeneration. Mutations in the TARDBP gene, which codes for TDP-43, have been recently reported in familial and sporadic amyotrophic lateral sclerosis (ALS) cases. METHODS: To further define the spectrum and frequency of TARDBP mutations, we present genetic analysis data on TARDBP in 314 ALS mainly Italian patients, including 16 subjects with non-SOD1 familial ALS. RESULTS: We identified four heterozygous missense mutations in five unrelated ALS patients (1.6%). Two of these mutations (p.G348C and p.A382T) were detected in carriers coming from families with an autosomal dominant transmission of different geographic origin (Belgian and Italian, respectively). The Belgian pedigree showed several affected members within five generations and with variable clinical features. Two novel mutations (p.G294V and p.G295S) were identified in two sporadic cases. CONCLUSION: The identification of five ALS patients carrying TARDBP alterations extends the spectrum of TARDBP mutations and supports the pathological role of TDP-43 in motor neurone disease. Our findings provide evidence that TARDBP mutations are not frequent in Italian sporadic ALS patients (1%); however, combined with the literature, our data further support TARDBP mutations as a relevant cause of familial ALS.Journal ArticleResearch Support, Non-U.S. Gov'tFLWINinfo:eu-repo/semantics/publishe