Dr. Guy Libourel, Observatoire de la Côte d’Azur, Nice, visited UTOPS and gave a lecture “From Asteroid to Earth: The first results of the NASA OSIRIS-REx mission”.
He talked about the latest results on the mineralogy and petrology of samples retrieved from the asteroid Bennu.
(2024.4.30)
Joint Press Release
Shogo Tachibana (Professor, UTOPS, Department of Earth and Planetary Science, ISAS)
A research group led by Professor Yuki Kimura, Hokkaido University, Chief Researcher Takeharu Kato, Senior Staff, Satoshi Anada, Senior Engineer Ryuji Yoshida, and Chief Researcher Kazuo Yamamoto of the Fine Ceramics Center, Senior Staff Toshiaki Tanigaki of the Research and Development Group, Hitachi, Ltd, Associate Professor Kosuke Kurosawa of Kobe University, Professor Tomoki Nakamura of Tohoku University, Assistant Professor Masahiko Sato (currently Associate Professor at Tokyo University of Science) and Professor Shogo Tachibana of the School of Science at the University of Tokyo, Professor Takaaki Noguchi and Assistant Professor Toru Matsumoto of Kyoto University have examined the surface of samples (grains of sand) recovered from the asteroid Ryugu by the explorer Hayabusa2 using electron holography, a technique using an electron microscope that can visualize magnetic flux on a nano scale. As a result, they discovered a new microstructure consisting of framboidal pseudo-magnetite, which formed from magnetite (Fe3O4) particles through losing their magnetic properties by reduction, and numerous iron nanoparticles with a vortex magnetic domain structure scattered around pseudo-magnetite. Magnetic minerals are natural magnetic recording medium that can record environmental information of the early solar system. Previously known recording medium were almost exclusively magnetite and pyrrhotite which form during aqueous alteration in asteroids. The new microstructures discovered in this study, especially the large number of iron nanoparticles, may record information on the magnetic field in the early solar system after the aqueous alteration, which was not known before. Therefore, it is expected to be used as a new magnetic recording medium that can provide information on the formation history of the solar system, which has not yet been explored, thereby opening up a new science on the formation of the solar system.
The research results were published in Nature Communications on Monday, April 29, 2024 (JST).
For more information, please refer to the following
Graduate School of Science web: https://www.s.u-tokyo.ac.jp/en/press/10332/
Publication URL: https://www.nature.com/articles/s41467-024-47798-0
