著者

Naoki HIRAKAWA Yoko KEBUKAWA Takazo SHIBUYA Hisahiro UEDA Kensei KOBAYASHI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.118, no.1, pp.220913, 2023 (Released:2023-07-26)

参考文献数

53

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Several investigations have demonstrated that olivine may be used to simulate geochemical and cosmochemical reactions. Since olivine in extra-terrestrial samples has varying forsterite numbers and natural olivine contains inevitable impurities, synthetic olivine with the requisite forsterite number has been prepared for various experimental research. This study aimed to synthesize Fe-bearing olivine via synthetic experiments conducted at near-solidus temperatures and elucidate the formation and decomposition mechanisms of the obtained Fe-bearing olivine. Specifically, we attempted to synthesize Fo60 [Forsterite number = 100 × Mg/(Mg + Fe) = 60] olivine using a mixture of analytical-grade SiO2, MgO, and Fe2O3. To clarify the stability of the obtained olivine, the temperature range (1350-1500 °C) and heating durations (1.5 or 15 h) were controlled under a constant oxygen fugacity of QFM-1 log units.The target olivine (Fo60) was obtained via heating for 1.5 h at 1500 °C, corresponding to the solidus line temperature. However, maintaining the olivine obtained at this temperature for 15 h resulted in a much higher forsterite number owing to the formation of oxidized minerals of olivine (magnetite and pyroxene). Similar oxidation products were also obtained following heating at 1450 °C for 15 h. These results indicated the primary formation of Fe-bearing olivine during 1.5 h of heating and its subsequent decomposition to magnetite and pyroxene owing to the high-temperature oxidation at near-solidus temperatures during heating for 1.5-15 h. These findings highlight a strategy for synthesizing Fe-bearing olivine and the associated mechanism and provide experimental insights into the decomposition of olivine in natural igneous rocks.

著者

Yuto MOGI Yoko KEBUKAWA Kensei KOBAYASHI

出版者

The Japan Society for Analytical Chemistry

雑誌

Analytical Sciences (ISSN:09106340)

巻号頁・発行日

pp.21P188, (Released:2021-08-13)

被引用文献数

2

著者

Walaa Elmasry Yoko Kebukawa Kensei Kobayashi

雑誌

JpGU-AGU Joint Meeting 2020

巻号頁・発行日

2020-03-13

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Extraterrestrial delivery of organic compounds including amino acids to the early Earth during the late heavy bombardment (3.8-4.5 billion years ago) may have been important for the origin of life. Recently, it is suggested that chondritic organic matter was produced through reactions of interstellar formaldehyde, followed by condensation, and carbonization probably during hydrothermal alteration on chondritic asteroids (Cody et al 2011). Furthermore, Kebukawa et al. (2013, 2015) illustrated that the presence of ammonia significantly enhances the yields of IOM from formaldehyde via formose reaction at 150 °C, producing amino acids. Meteorites serve as delivery systems for extraterrestrial phyllosilicate minerals to Earth. Phyllosilicates may act as absorbents and catalysts for the reactions of organic precursor molecules in the early solar system (Pearson et.al 2002). In the current research, we are studying formations of amino acid at 150 °C and reveal the expected role of minerals, namely, montmorillonite, olivine and serpentine for amino acid productions in water-bearing planetesimals.We synthesized organic compounds using a mixture of water, formaldehyde and ammonia (H2O, H2CO, NH3) in a ratio of 100:7:1 with adding minerals (10 g/ L) by simulating primordial materials in comets and asteroids. Aqueous solutions were heated at 150 °C for 24, and 72 hours. The resulted products were divided into two parts, the first part analyzed using a FT/IR, and GFC, while the other one was acid hydrolyzed, desalted, and subjected to amino acid analysis using an HPLC.In HPLC analysis, considerable amounts of various amino acids including glycine and alanine were detected. Moreover, presence of non-protein amino acids (β-Ala, γ-ABA) is considered as an evidence for extraterrestrial origin and against terrestrial contamination. Our preliminary results showed that the obtained amount of amino acids was elevated with the presence of minerals. FT/IR spectra of samples with minerals showed more spectral intensities than samples without minerals due to synthesis of more organic compounds. GFC showed that high molecular weight organic compounds were formed which may be characterized as amino acid precursors that maintain stable at high temperature and longer durations giving various kinds of amino acids after acid hydrolysis. These results suggested that various amino acids could be formed abiotically via a mixture of formaldehyde, ammonia, and water, as well as, the associated minerals act as catalysts to produce amino acid precursors during aqueous activities in the planetesimals.References:Cody, G. D. et al. PNAS 108, 19171–19176 (2011).Kebukawa, Y., David Kilcoyne, A. L. & Cody, G. D. The Astrophysical Journal 771, 19 (2013).Kebukawa, Y. & Cody, G. D. Icarus 248, 412–423 (2015).Pearson, V. K. Meteoritics & Planetary Science 37, 1829–1833 (2002).

著者

Junichi HARUYAMA Isao KAWANO Takashi KUBOTA Masatsugu OTSUKI Hiroki KATO Toshihiko NISHIBORI Takahiro IWATA Yukio YAMAMOTO Yoshiaki ISHIHARA Aiko NAGAMATSU Kazuhito SHIMADA Toshiaki HASENAKA Tomokatsu MOROTA Masaki N. NISHINO Ko HASHIZUME Kazuto SAIKI Motomaro SHIRA Goro KOMATSU Nobuyuki HASEBE Hisayoshi SHIMIZU Hideaki MIYAMOTO Kensei KOBAYASHI Shinichi YOKOBORI Tatsuhiro MICHIKAMI Satoru YAMAMOTO Yasuhiro YOKOTA Hitoshi ARISUMI Genya ISHIGAMI Katsushi FURUTANI Yuichi MICHIKAWA

出版者

THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES

雑誌

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN (ISSN:18840485)

巻号頁・発行日

vol.14, no.ists30, pp.Pk_147-Pk_150, 2016 (Released:2017-02-14)

被引用文献数

1 5

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We are planning to explore the caverns through the skylight holes on the Moon and Mars. The holes and their associated subsurface caverns are among the most important future exploration targets. The importance of the lunar and Martian holes and their associated caverns is categorized from two aspects: (1) fresh materials are easily observed and sampled there, and (2) the subsurface caverns provide a safe, quiet environment. The expectation of lunar and Martian hole and cavern exploration is increasing in Japan. We name the project as UZUME (Unprecedented Zipangu (Japan) Underworld of the Moon Exploration) whose name is after a Japanese mythology. The ultimate purpose of the UZUME project is to investigate how to expand human activity and survival in space and on extraterrestrial bodies.

著者

Akihiko Yamagishi Shin-ichi Yokobori Yoshitaka Yoshimura Masamichi Yamashita Hirofumi Hashimoto Takashi Kubota Hajime Yano Junichi Haruyama Makoto Tabata Kensei Kobayashi Hajime Honda Yuichi Utsumi Tsunemasa Saiki Takashi Itoh Atsuo Miyakawa Kenji Hamase Takeshi Naganuma Hajime Mita Kenichi Tonokura Sho Sasaki Hideaki Miyamoto

出版者

日本宇宙生物科学会

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.24, no.2, pp.67-82, 2010 (Released:2012-06-26)

参考文献数

114

被引用文献数

1 12

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Liquid water is considered to be critical for life. Gibbs free energy is another factor that is important to sustain life for long durations. Gibbs free energy is obtained by reactions between reductants and oxidants, or from any other non-equilibrium state of matter. As an example, aerobic organisms use carbohydrates and oxygen to obtain energy. Many types of chemoautotrophic mechanisms are known for this process as well. On the surface of Mars, methane and oxidative compounds such as ferric oxide, sulfate and perchloride, which could provide redox-derived Gibbs free energy, have been detected. Iron-dependent methane oxidizing bacteria have been found in marine environments on Earth. This finding suggests the possible presence of methane-oxidizing bacteria on the Mars surface, if the local thermal environment and other resources permit proliferation and metabolism of bacteria. Our project aims to search for methane-oxidizing microbes on the Mars surface. Martian soil will be sampled from a depth of about 5 - 10 cm below the surface, where organisms are expected to be protected from the harsh hyper-oxidative environment of the Mars surface. Small particles less than 0.1 mm or 1 mm will be sieved from the sample, before being transferred to the analysis section by a micro-actuator. The particles will be stained with a cocktail of fluorescent reagents, and examined by fluorescence microscopy. A combination of fluorescent dyes has been selected to identify life forms in samples. A membrane-specific dye or a combination of dyes will be used to detect membranes surrounding the "cell". An intercalating fluorescent dye such as SYBR Green will be used to detect genetic compounds such as DNA. A substrate dye that emits fluorescence upon cleavage by a catalytic reaction will be used to detect the catalytic activity of the "cell". A combination of staining reagents has been chosen based on the definition of life. A membrane separating a cell from the ambient environment may lead to identification of an "individual". DNA or genetic material is required for "replication" of the life form. Catalytic reactions carried out by enzymes drive "metabolism". This combination of strategies will also be useful for detecting pre-biotic organic material as well as remnants of ancient life. Hydrolysis of the polymers in the "cell" followed by HPLC or soft ionization MS for amino acid analysis will be effective for examining whether Martian life is identical to or different from terrestrial life. The number and type of the amino acids as well as their chirality will be analyzed to distinguish whether the polymers are contaminants from Earth.