Our goal is to describe atoms that represent element distribution of the Solar system that are continuously evolving from the beginning to the future. To understand the Solar system with spatial scale 1013 m, we analyze planetary materials that are from different origin with different processes, and determine element and isotope compositions with spatial resolution down to 10-9 m.

Planetary materials besides terrestrial ones are the rolling stones that are sampled with locality unknown. To fill the important missing information, we developed a protocol that is to determine multiple-elements, multiple-isotopes, and multiple-phases. We referred the approach to be 'comprehensive' and construct an analytical system that let us do so. The system acts as a gigantic machine with numerous instruments glued by analytical methods and disciplined people. The disciplines and samples would be taken over to the next generation to sustain our science.

We work as a team and prefer arguments scientifically.


We suggest that a rubble pile asteroid (Itokawa, Ryugu, or Bennu) was turned from a comet


On the 15th February (2013), a meteorite impacted Chelyabinsk state in Russia (see YouTube). It is referred to as the Chelyabinsk meteorite and was categorized as an ordinary chondrite. It has a genetic relationship to the asteroid Itokawa, which is also composed from fragments of ordinary chondrite.

We have applied our comprehensive analyses to the Chelyabinsk meteorite. ... Read More ... 続きを読む


Nakamura, E., Kunihiro, T., Ota, T., Sakaguchi, C., Tanaka, R., Kitagawa, H., Kobayashi, K., Yamanaka, M.,, Yuri Shimaki, Bebout, G.E.,, Miura, H., Yamamoto, T., Malkovets, V., Grokhovsky, V., Koroleva, O. and Litasov, K., Hypervelocity collision and water-rock interaction in space preserved in the Chelyabinsk ordinary chondrite, Proceedings of the Japan Academy Series B, 95(4), 165-177, dream/20190115102242-432018, 2019.

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Kunihiro, T., Ota, T., Nakamura, E., Lithium- and oxygen-isotope compositions of chondrule constituents in the Allende meteorite, Geochimica et Cosmochimica Acta, 252, 107-125, 2019.

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Hao, H., Campbell, I.H., Richards, J.P., Nakamura, E., Sakaguchi, C., Platinum-Group Element Geochemistry of the Escondida Igneous Suites, Northern Chile: Implications for Ore Formation, J. of Petrol., egz004, 2019.

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Hibiya, Y., Archer, G.J., Tanaka, R., Sanborn, M.E., Sato, Y., Iizuka, T., Ozawa, K., Walker, R.J., Yamaguchi, A., Yin, Q-Z., Nakamura, T., Irving, A.J., The origin of the unique achondrite Northwest Africa 6704: Constraints from petrology, chemistry and Re–Os, O and Ti isotope systematics, Geochim. Cosmochim. Acta, 245, 597-627, 2019.

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April 16, 14:00 PM in 3F Seminar Room
Seminar by Atsushi Sakuda (Osaka Prefecture Univ)

Mar. 27, 10:00 AM in 3F Seminar Room
Seminar by Dr. Akira Miura (JAXA/ISAS)

Mar. 19, 10:00 AM in 3F Seminar Room
Seminar by Kucukarsklan Nurcan

Mar. 13, 10:00 AM in 3F Seminar Room
Seminar by Li Wei (grad. student, China Univ. Geosciences)

Mar. 12, 10:00 AM in 3F Seminar Room
Seminar by Hajime Taniuchi (Hokkaido Univ.)