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A medium‐grade, poorly weathered CO3‐type meteorite was subjected to artificial space weathering by 1 keV protons in three subsequent steps, with gradually increasing doses from 1011 to 1017 protons per cm2. The resulting mineral modifications were identified by Raman spectroscopy, with specific emphasis on main minerals such as olivine (bands: 817, 845 cm−1), pyroxene (1007 cm−1), and partly amorphous feldspar (509 cm−1), considering variation in band shift and bandwidth (full width at half maximum, FWHM). After the first and second irradiations, variable band position changes were observed, probably from metastable alterations by Mg loss of the minerals, while the third stronger irradiation showed band shift dominated by amorphization. The olivine and pyroxene show weak increase in FWHM after the first irradiation, while more changes happened after the second and third irradiations. The flux after the third irradiation was higher than in other works, caused stronger damage in crystal lattice, partly resembling to dimerization as described by shock metamorphism. The glassy feldspar was characterized by high FWHM values already at the beginning, indicating weak crystallinity already that become even less crystallized, thus their bands disappeared after the third irradiation. Bands of hydrous minerals (goethite clay, chlorite) were not visible after the third irradiation, confirming some earlier results in the literature. Based on our results, moderately fresh surfaces could show stochastic but small spectral differences compared to the fresh most meteorites by metastable mineral alterations. The interpretation of Raman spectra of heavily space‐weathered surfaces could further benefit from the joint evaluation of alteration induced by both shock impact alteration and space weathering. [ABSTRACT FROM AUTHOR]

Raman and infrared measurements of the same locations were conducted on a northwest African (NWA) 10580 CO3 meteorite sample, before and after three proton irradiations (1 keV ion energy using 1011, 1014, and 1017 ion/cm2 fluent values), to simulate space weathering effects. In the case of Raman spectroscopy, both FWHM and peak positions of the major olivine and pyroxene bands changed after the irradiation, and the minor bands disappeared. In the FTIR spectra, the minor bands of olivine and pyroxene also disappeared; meanwhile, major IR bands of pyroxene remained visible, demonstrating both positive and negative peak shifts, and the olivines were characterised only by negative peak shifts. The olivines were characterised by negative FWHM changes for major bands, but positive FWHM changes for minor bands. The pyroxenes were characterised by elevated FWHM changes for minor bands after the irradiation. The disappearance of minor bands both of IR and Raman spectra indicates the amorphization of minerals. The negative peak shift in IR spectra indicates Mg loss for olivine and pyroxene, in agreement with the literature. The Raman spectra are characterised by positive peak shift and positive FWHM changes; the IR spectra are characterised by a negative peak shift. The Mg loss, which was detected by negative peak shifts of FTIR bands, may be caused by distortion of the crystal structure, which could be detected by a positive peak shift in Raman spectra. This joint observation and interpretation has not been formulated in the literature, but indicates further possibilities in the confirmation of mineral changes by different instruments. Shock alteration-based observations by other researchers could be used as a reference for irradiation experiments as irradiation makes a similar structural alteration, like a low-grade shock metamorphism. [ABSTRACT FROM AUTHOR]

Abstract: Between 15 and 25 April 2011 in the framework of the PolAres programme of the Austrian Space Forum, a five-day field test of the Aouda.X spacesuit simulator was conducted at the Rio Tinto Mars-analogue site in southern Spain. The field crew was supported by a full-scale Mission Control Center (MCC) in Innsbruck, Austria. The field telemetry data were relayed to the MCC, enabling a Remote Science Support (RSS) team to study field data in near-real-time and adjust the flight planning in a flexible manner. We report on the experiences in the field of robotics, geophysics (Ground Penetrating Radar) and geology as well as life sciences in a simulated spaceflight operational environment. Extravehicular Activity (EVA) maps had been prepared using Google Earth and aerial images. The Rio Tinto mining area offers an excellent location for Mars analogue simulations. It is recognised as a terrestrial Mars analogue site because of the presence of jarosite and related sulphates, which have been identified by the NASA Mars Exploration Rover “Opportunity” in the El Capitan region of Meridiani Planum on Mars. The acidic, high ferric-sulphate content water of Rio Tinto is also considered as a possible analogue in astrobiology regarding the analysis of ferric sulphate related biochemical pathways and produced biomarkers. During our Mars simulation, 18 different types of soil and rock samples were collected by the spacesuit tester. The Raman results confirm the presence of minerals expected, such as jarosite, different Fe oxides and oxi-hydroxides, pyrite and complex Mg and Ca sulphates. Eight science experiments were conducted in the field. In this contribution first we list the important findings during the management and realisation of tests, and also a first summary of the scientific results. Based on these experiences suggestions for future analogue work are also summarised. We finish with recommendations for future field missions, including the preparation of the experiments, communication and data transfer – as an aid to the planning of future simulations. [Copyright &y& Elsevier]