Mathias Blumers

Distinct microbial populations are tightly linked to the profile of dissolved iron in the methanic sediments of the Helgoland mud area, North Sea

Iron reduction in subseafloor sulfate-depleted and methane-rich marine sediments is currently a subject of interest in subsurface geomicrobiology. While iron reduction and microorganisms involved have been well studied in marine surface sediments, little is known about microorganisms responsible for iron reduction in deep methanic sediments. Here, we used quantitative PCR-based 16S rRNA gene copy numbers and pyrosequencing-based relative abundances of bacteria and archaea to investigate covariance between distinct microbial populations and specific geochemical profiles in the top 5 m of sediment cores from the Helgoland mud area, North Sea. We found that gene copy numbers of bacteria and archaea were specifically higher around the peak of dissolved iron in the methanic zone (250–350 cm). The higher copy numbers at these depths were also reflected by the relative sequence abundances of members of the candidate division JS1, methanogenic and Methanohalobium/ANME-3 related archaea. The distribution of these populations was strongly correlated to the profile of pore-water Fe2+ while that of Desulfobacteraceae corresponded to the pore-water sulfate profile. Furthermore, specific JS1 populations also strongly co-varied with the distribution of Methanosaetaceae in the methanic zone. Our data suggest that the interplay among JS1 bacteria, methanogenic archaea and Methanohalobium/ANME-3-related archaea may be important for iron reduction and methane cycling in deep methanic sediments of the Helgoland mud area and perhaps in other methane-rich depositional environments.

Mauna Kea, Hawaii, as an Analog Site for Future Planetary Resource Exploration: Results from the 2010 ILSO-ISRU Field-Testing Campaign

The major advances in knowledge of extraterrestrial bodies come from in situ measurements on robotized measuring devices deployed by international space missions, for example, on the Moon and Mars. It is essential to test these instruments in environments on Earth thatbearacloseresemblancetoplanetaryconditions.Withintheframeworkofthe2010InternationalLunarSurfaceOperationInSituResource Utilization (2010 ILSO-ISRU) Analog Test, a suite of scientific instruments developed for in situ lunar research was field tested and cali- brated on the Mauna Kea volcano in Hawaii on January 27 to February 11, 2010. This site will beused as one ofthe future standard test sites to calibrate instruments forin situ lunarresearch.In 2010, atotalof eight scientificteams tested instrument capabilities at the test site.In this paper, a geological setting for this new field-test site, a description of the instruments that were tested during the 2010 ILSO-ISRU field campaign, and a short discussion of each instrument about the validity and use of the results obtained during the test are provided. These results will serve as reference for future test campaigns. DOI: 10.1061/(ASCE)AS.1943-5525.0000200.

Field-portable Mössbauer spectroscopy on Earth, the Moon, Mars, and beyond

ABSTRACT Iron occurs naturally as Fe2+, Fe3+, and, to a lesser extent, as Fe0. Many fundamental (bio)geochemical processes are based on redox cycling between these oxidation states. Mössbauer spectroscopy provides quantitative information about the distribution of Fe among its oxidation states, identification of Fe-bearing phases, and relative distribution of Fe among those phases. Portable, miniaturised Mössbauer spectrometers were developed for NASAs Mars Exploration Rovers (in operation since 2004) and provide a means for non-destructive, in-situ field investigations. On Mars, these instruments provided evidence for aqueous activity with implications for habitability, were applied in geological mapping of the landing sites, and helped to identify meteorites, for example. On Earth, they were used in field studies of green rust, the identification of air pollution sources, or the study of archaeological artefacts. Their application to in-situ resource utilisation (ISRU) on the Moon has been demonstrated in a recent NASA field test of hardware for oxygen production. A new detector system in an advanced version of these instruments is based on Si Drift Detectors and permits the simultaneous acquisition of X-ray fluorescence spectra to determine elemental compositions.

The miniaturized Möessbauer spectrometer MIMOS II for the Phobos-Grunt mission

Möessbauer spectroscopy is a powerful tool for the mineralogical analysis of Fe-bearing materials. The miniaturized Möessbauer spectrometer MIMOS II has already been working on the surface of Mars for 6 years as part of the NASA Mars Exploration Rovers mission. The improved version of the instrument is a component of the scientific payload of the Phobos-Grunt mission. The scientific objectives of the instrument are the following: to identify the iron-bearing phases, to determine the quantitative distribution of iron among these phases, and to determine the distribution of iron among its oxidation states.

In-situ Mössbauer Spectroscopy with MIMOS II at Rio Tinto, Spain

The Rio Tinto, located in southwest Spain, exhibits a nearly constant, acidic pH-value along its course. Due to the formation of sulfate minerals, Rio Tinto is considered a potential analogue site for sulfate-rich regions on Mars, in particular at the landing site of the Mars Exploration Rover Opportunity, where the ferric sulfate mineral jarosite was identified with Opportunitys Mossbauer spectrometer. Primary and secondary mineralogy was investigated in situ with portable Raman and Mossbauer spectrometers at four different Rio Tinto sampling sites. The two techniques analyse different sample portions due to their specific field of view and sampling depth and provide complementary mineralogical information.

Iron(III) Complexes on a Dendrimeric Basis and Various Amine Core Investigated by Mössbauer Spectroscopy

Dendrimers of various generations were synthesized by the divergent method. Starting from various amine cores (G0a, G0b, G0c) the generations were built by reaction of the amine with acrylnitrile followed by hydrogenation with DIBAL-H. Treatment with salicylaldehyde creates a fivefold coordination sphere for iron in the molecular periphery. The resulting multinuclear coordination compounds are investigated by Mossbauer spectroscopy.

APXS and MIMOS IIA: Planetary and terrestrial applications

Both Alpha Particle X-ray Spectrometer (APXS) and the Miniaturized Moessbauer Spectrometer (MIMOS II) have shown their performances in space missions and terrestrial applications. Taking advantage of the challenges of space missions both instruments have become very powerful tools, even small in mass and dimensions.

Robotic Exploration of Planetary Surfaces – Rover Technologies Developed for Space Exploration

Mobility is a key feature for any science mission and for space exploration in general. Missions with mobile systems provide a much wider spectrum of outcomes by employing a higher number of samples within an increased area of exploration. The additional degree of freedom of a rover in comparison to a lander or even a robotic arm allows the mission to be flexibly adapted to the landing site as it is encountered.