MMX Project Team

Takahiro Iwata

  (岩田 隆浩)

Profile Information

Affiliation
associate professor, Institute of Space and Astronautical Science, Department of Solar System Science, Japan Aerospace Exploration Agency
School of Physical Sciences Department of Space and Astronautical Science, The Graduate University for Advanced Studies
Degree
理学博士(Feb, 1989, Nagoya University)

Researcher number
20201949
ORCID ID
 https://orcid.org/0000-0002-4613-7956
J-GLOBAL ID
202001003492525290
researchmap Member ID
R000013755

 

(併任)

 はやぶさ2プロジェクトチーム

 国際宇宙探査センター火星衛星探査機プロジェクトチーム

(兼務)

 関西学院大学大学院理工学研究科 客員教授


Papers

 99
  • Chihiro Uemura, Akio Nakahara, Yousuke Matsuo, Takahiro Iwata
    Physical Review E, 109(3), Mar 15, 2024  Peer-reviewedLast author
  • Moe Matsuoka, Ei-ichi Kagawa, Kana Amano, Tomoki Nakamura, Eri Tatsumi, Takahito Osawa, Takahiro Hiroi, Ralph Milliken, Deborah Domingue, Driss Takir, Rosario Brunetto, Antonella Barucci, Kohei Kitazato, Seiji Sugita, Yuri Fujioka, Osamu Sasaki, Shiho Kobayashi, Takahiro Iwata, Tomokatsu Morota, Yasuhiro Yokota, Toru Kouyama, Rie Honda, Shingo Kameda, Yuichiro Cho, Kazuo Yoshioka, Hirotaka Sawada, Masahiko Hayakawa, Naoya Sakatani, Manabu Yamada, Hidehiko Suzuki, Chikatoshi Honda, Kazunori Ogawa, Kei Shirai, Cateline Lantz, Stefano Rubino, Hisayoshi Yurimoto, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Hiroshi Naraoka, Kanako Sakamoto, Shogo Tachibana, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Masanao Abe, Tatsuaki Okada, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Sei-ichiro Watanabe, Yuichi Tsuda
    Communications Earth & Environment, 4(1), Sep 27, 2023  
    Abstract Returned samples from Cb-type asteroid (162173) Ryugu exhibit very dark spectra in visible and near-infrared ranges, generally consistent with the Hayabusa2 observations. A critical difference is that a structural water absorption of hydrous silicates is around twice as deep in the returned samples compared with those of Ryugu’s surface, suggesting Ryugu surface is more dehydrated. Here we use laboratory experiments data to indicate the spectral differences between returned samples and asteroid surface are best explained if Ryugu surface has (1) higher porosity, (2) larger particle size, and (3) more space-weathered condition, with the last being the most effective. On Ryugu, space weathering by micrometeoroid bombardments promoting dehydration seem to be more effective than that by solar-wind implantation. Extremely homogeneous spectra of the Ryugu’s global surface is in contrast with the heterogeneous S-type asteroid (25143) Itokawa’s spectra, which suggests space weathering has proceeded more rapidly on Cb-type asteroids than S-type asteroids.
  • Yuichiro Ezoe, Ryu Funase, Harunori Nagata, Yoshizumi Miyoshi, Hiroshi Nakajima, Ikuyuki Mitsuishi, Kumi Ishikawa, Masaki Numazawa, Yosuke Kawabata, Shintaro Nakajima, Ryota Fuse, Ralf C. Boden, Landon Kamps, Tomokage Yoneyama, Kouichi Hagino, Yosuke Matsumoto, Keisuke Hosokawa, Satoshi Kasahara, Junko Hiraga, Kazuhisa Mitsuda, Masaki Fujimoto, Munetaka Ueno, Atsushi Yamazaki, Hiroshi Hasegawa, Takefumi Mitani, Yasuhiro Kawakatsu, Takahiro Iwata, Hiroyuki Koizumi, Hironori Sahara, Yoshiaki Kanamori, Kohei Morishita, Daiki Ishi, Aoto Fukushima, Ayata Inagaki, Yoko Ueda, Hiromi Morishita, Yukine Tsuji, Runa Sekiguchi, Takatoshi Murakawa, Kazuma Yamaguchi, Rei Ishikawa, Daiki Morimoto, Yudai Yamada, Shota Hirai, Yuki Nobuhara, Yownin Albert M. Leung, Yamato Itoigawa, Ryo Onodera, Satoru Kotaki, Shotaro Nakamura, Ayumi Kiuchi, Takuya Matsumoto, Midori Hirota, Kazuto Kashiwakura
    Journal of Astronomical Telescopes, Instruments, and Systems, 9(03), Sep 12, 2023  Peer-reviewed
  • Kohji Tsumura, Shuji Matsuura, Kei Sano, Takahiro Iwata, Hajime Yano, Kohei Kitazato, Kohji Takimoto, Manabu Yamada, Tomokatsu Morota, Toru Kouyama, Masahiko Hayakawa, Yasuhiro Yokota, Eri Tatsumi, Moe Matsuoka, Naoya Sakatani, Rie Honda, Shingo Kameda, Hidehiko Suzuki, Yuichiro Cho, Kazuo Yoshioka, Kazunori Ogawa, Kei Shirai, Hirotaka Sawada, Seiji Sugita
    Earth, Planets and Space, 75(1), Aug 22, 2023  Peer-reviewed
    Abstract Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as $$n(r) \sim r^{-\alpha }$$, and the exponent $$\alpha \sim 1.3$$ was obtained by previous observations from interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of $$\alpha $$ based on ZL observations from interplanetary space outside Earth’s orbit have been performed since then. Here, we introduce initial results for the radial profile of the ZL at optical wavelengths observed over the range 0.76$$-$$1.06 au by ONC-T aboard the Hayabusa2# mission in 2021-2022. The ZL brightness we obtained is well reproduced by a model brightness, although there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The radial power-law index we obtained is $$\alpha = 1.30 \pm 0.08$$, which is consistent with previous results based on ZL observations. The dominant source of uncertainty arises from the uncertainty in estimating the diffuse Galactic light (DGL). Graphical Abstract
  • T. Nakamura, M. Matsumoto, K. Amano, Y. Enokido, M. E. Zolensky, T. Mikouchi, H. Genda, S. Tanaka, M. Y. Zolotov, K. Kurosawa, S. Wakita, R. Hyodo, H. Nagano, D. Nakashima, Y. Takahashi, Y. Fujioka, M. Kikuiri, E. Kagawa, M. Matsuoka, A. J. Brearley, A. Tsuchiyama, M. Uesugi, J. Matsuno, Y. Kimura, M. Sato, R. E. Milliken, E. Tatsumi, S. Sugita, T. Hiroi, K. Kitazato, D. Brownlee, D. J. Joswiak, M. Takahashi, K. Ninomiya, T. Takahashi, T. Osawa, K. Terada, F. E. Brenker, B. J. Tkalcec, L. Vincze, R. Brunetto, A. Aléon-Toppani, Q. H. S. Chan, M. Roskosz, J.-C. Viennet, P. Beck, E. E. Alp, T. Michikami, Y. Nagaashi, T. Tsuji, Y. Ino, J. Martinez, J. Han, A. Dolocan, R. J. Bodnar, M. Tanaka, H. Yoshida, K. Sugiyama, A. J. King, K. Fukushi, H. Suga, S. Yamashita, T. Kawai, K. Inoue, A. Nakato, T. Noguchi, F. Vilas, A. R. Hendrix, C. Jaramillo-Correa, D. L. Domingue, G. Dominguez, Z. Gainsforth, C. Engrand, J. Duprat, S. S. Russell, E. Bonato, C. Ma, T. Kawamoto, T. Wada, S. Watanabe, R. Endo, S. Enju, L. Riu, S. Rubino, P. Tack, S. Takeshita, Y. Takeichi, A. Takeuchi, A. Takigawa, D. Takir, T. Tanigaki, A. Taniguchi, K. Tsukamoto, T. Yagi, S. Yamada, K. Yamamoto, Y. Yamashita, M. Yasutake, K. Uesugi, I. Umegaki, I. Chiu, T. Ishizaki, S. Okumura, E. Palomba, C. Pilorget, S. M. Potin, A. Alasli, S. Anada, Y. Araki, N. Sakatani, C. Schultz, O. Sekizawa, S. D. Sitzman, K. Sugiura, M. Sun, E. Dartois, E. De Pauw, Z. Dionnet, Z. Djouadi, G. Falkenberg, R. Fujita, T. Fukuma, I. R. Gearba, K. Hagiya, M. Y. Hu, T. Kato, T. Kawamura, M. Kimura, M. K. Kubo, F. Langenhorst, C. Lantz, B. Lavina, M. Lindner, J. Zhao, B. Vekemans, D. Baklouti, B. Bazi, F. Borondics, S. Nagasawa, G. Nishiyama, K. Nitta, J. Mathurin, T. Matsumoto, I. Mitsukawa, H. Miura, A. Miyake, Y. Miyake, H. Yurimoto, R. Okazaki, H. Yabuta, H. Naraoka, K. Sakamoto, S. Tachibana, H. C. Connolly, D. S. Lauretta, M. Yoshitake, M. Yoshikawa, K. Yoshikawa, K. Yoshihara, Y. Yokota, K. Yogata, H. Yano, Y. Yamamoto, D. Yamamoto, M. Yamada, T. Yamada, T. Yada, K. Wada, T. Usui, R. Tsukizaki, F. Terui, H. Takeuchi, Y. Takei, A. Iwamae, H. Soejima, K. Shirai, Y. Shimaki, H. Senshu, H. Sawada, T. Saiki, M. Ozaki, G. Ono, T. Okada, N. Ogawa, K. Ogawa, R. Noguchi, H. Noda, M. Nishimura, N. Namiki, S. Nakazawa, T. Morota, A. Miyazaki, A. Miura, Y. Mimasu, K. Matsumoto, K. Kumagai, T. Kouyama, S. Kikuchi, K. Kawahara, S. Kameda, T. Iwata, Y. Ishihara, M. Ishiguro, H. Ikeda, S. Hosoda, R. Honda, C. Honda, Y. Hitomi, N. Hirata, N. Hirata, T. Hayashi, M. Hayakawa, K. Hatakeda, S. Furuya, R. Fukai, A. Fujii, Y. Cho, M. Arakawa, M. Abe, S. Watanabe, Y. Tsuda
    Science, 379(6634), Feb 24, 2023  Peer-reviewed
    Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide–bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu’s parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu’s parent body formed ~2 million years after the beginning of Solar System formation.

Misc.

 45

Research Projects

 5