Applications of mössbauer spectroscopy in meteoritical and planetary science, part ii: Differentiated meteorites, moon, and mars

Mössbauer (nuclear γ-resonance) spectroscopy is a powerful technique which is actively used in various fields from physics and chemistry to biology and medicine. Rudolf L. Mössbauer, who observed nuclear γ-resonance and published his results in 1958, got a Nobel Prize in physics in 1961 for this discovery.57 Fe is the most widely used nucleus in Mössbauer spectroscopy. Therefore, a large variety of compounds containing iron can be studied by Mössbauer spectroscopy. It is well known that planetary matter contains various iron-bearing phases and minerals. Therefore, the extraterrestrial material from different meteorites, asteroids, and planets can be studied using57 Fe Mössbauer spectroscopy as an additional powerful technique. Two parts of this review consider the results of more than 50 years of experience of Mössbauer spectroscopy applied for the studies of various meteorites, soils, and rocks from the Moon and a recent investigation of the Martian surface using two rovers equipped with miniaturized Mössbauer spectrometers. Part I considered the results of Mössbauer spectroscopy of undifferentiated meteorites. Part II discusses the results of Mössbauer spectroscopy of differentiated meteorites formed in asteroids and protoplanets due to matter differentiation, as well as Lunar and Martian matter. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This work was supported by the Ministry of Science and Higher Education of the Russian Federation, project No. FEUZ-2020-0060. The Zavaritsky Institute of Geology and Geochemistry of the Ural Branch of the Russian Academy of Sciences is supported by the Ministry of Science and Higher Education of the Russian Federation, project No. AAAA-A19-119071090011-6 (A.A.M.)

Mössbauer spectroscopy with a high velocity resolution applied for the study of meteoritic iron-bearing minerals

Mössbauer spectroscopy with a high velocity resolution was applied for study of iron-bearing minerals in different meteorites. The possibility of technique to reveal small variations in Mössbauer hyperfine parameters of the 57Fe in the non-equivalent M1 and M2 sites in olivines from Farmington L5 and Tsarev L5 ordinary chondrites and from Omolon and Seymchan pallasites was demonstrated. The necessity of accounting for the Fe and Ni occupation probabilities in the local microenvironments for non-equivalent sites M1, M2 and M3 in schreibersite, an iron nickel phosphide from Sikhote-Alin iron meteorite, in the fit of its Mössbauer spectra was shown. Variations in Mössbauer parameters of metal samples from visually different areas at the saw-cut surface of Chinga iron meteorite fragment with unknown origin were observed; these variations may be related to different metal phase composition and local variations of Ni concentration in the metal phases in these areas. © 2012 Elsevier B.V. All rights reserved

The mitochondrial genome of the moss Brachythecium rivulare (Hypnales, Brachytheciaceae)

© 2017, Pleiades Publishing, Ltd. The mitochondrial genome of the pleurocarpous moss Brachythecium rivulare has been sequenced and annotated. The genome consists of 104,460 base pairs and has approximately the same gene set and organization as other bryophyte mitogenomes. Whole mitochondrial genome comparison between B. rivulare and Physcomitrella patens, Tetraphis pellucida, Anomodon rugelii, and Anomodon attenuatus was performed. The primary cause of bryophyte mitochondrial gene length variation was found to be numerous indels in the introns. Bryophyte mitochondrial gene conservation level was estimated, and it was in a good congruence with the overall phylogeny of bryophytes with the percentage of mitogenome similarity being proportional to the age estimated by phylochronologic analysis. Annotation discrepancies in the analyzed mitogenome sequences were identified. The simple sequence repeat (SSR) content was evaluated, and candidate sites of RNA editing were predicted in the B. rivulare mitochondrial genome