Search

Your search keyword '"Shimaki, Y."' showing total 91 results
Start Over Author "Shimaki, Y."
91 results on '"Shimaki, Y."'

1. Effect of projectile shape and interior structure on crater size in strength regime

Author

Kadono, T., Arakawa, M., Tsujido, S., Yasui, M., Hasegawa, S., Kurosawa, K., Shirai, K., Okamoto, C., Ogawa, K., Iijima, Y., Shimaki, Y., and Wada, K.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Geophysics
Abstract

Experiments on crater formation in the strength regime were conducted using projectiles of various shapes with an aspect ratio of ~1, including both solid and hollow interiors. The surface diameter, inner (pit) diameter, and depth of the craters on basalt and porous gypsum targets were measured. Using the bulk density of the projectile, the surface diameter and depth for basalt and the pit diameter and depth for porous gypsum were scaled using the pi-scaling law for crater formation in the strength regime. The numerical code iSALE was used to simulate the impact of projectiles of various shapes and interior structure with similar bulk densities. Results show that the distributions of the maximum (peak) pressure experienced and particle velocity in the targets were similar regardless of projectile shape and interior structure, implying that the dimensions of the final craters were almost identical. This is consistent with the experimental results. Thus, we conclude that the size of the craters formed by the impact of projectiles with different shape and interior structure can be scaled using a conventional scaling law in the strength regime, using bulk density as projectile density., Comment: 38 pages, 9 figures, 4 tables, 1 supporting information, accepted for publication in Earth, Planets and Space

Published
2022
Full Text
View/download PDF

2. Hayabusa2 Extended Mission: New Voyage to Rendezvous with a Small Asteroid Rotating with a Short Period

Author

Hirabayashi, M., Mimasu, Y., Sakatani, N., Watanabe, S., Tsuda, Y., Saiki, T., Kikuchi, S., Kouyama, T., Yoshikawa, M., Tanaka, S., Nakazawa, S., Takei, Y., Terui, F., Takeuchi, H., Fujii, A., Iwata, T., Tsumura, K., Matsuura, S., Shimaki, Y., Urakawa, S., Ishibashi, Y., Hasegawa, S., Ishiguro, M., Kuroda, D., Okumura, S., Sugita, S., Okada, T., Kameda, S., Kamata, S., Higuchi, A., Senshu, H., Noda, H., Matsumoto, K., Suetsugu, R., Hirai, T., Kitazato, K., Farnocchia, D., Naidu, S. P., Tholen, D. J., Hergenrother, C. W., Whiteley, R. J., Moskovitz, N. A., Abell, P. A., and group, the Hayabusa2 extended mission study

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Hayabusa2 is the Japanese Asteroid Return Mission and targeted the carbonaceous asteroid Ryugu, conducted by the Japan Aerospace Exploration Agency (JAXA). The goal of this mission was to conduct proximity operations including remote sensing observations, material sampling, and a Small Carry-On Impact experiment, as well as sample analyses. As of September 2020, the spacecraft is on the way back to Earth with samples from Ryugu with no critical issues after the successful departure in November 2019. Here, we propose an extended mission in which the spacecraft will rendezvous with a small asteroid with ~30 m - ~40 m in diameter that is rotating at a spin period of ~10 min after an additional ~10-year cruise phase. We introduce that two scenarios are suitable for the extended mission. In the first scenario, the spacecraft will perform swing-by maneuvers at Venus once and Earth twice to arrive at asteroid 2001 AV43. In the second scenario, it will perform swing-by maneuvers at Earth twice to reach asteroid 1998 KY26. In both scenarios, the mission will continue until the early 2030s. JAXA recently released the decision that the spacecraft will rendezvous with 1998 KY26. This paper focuses on our scientific assessments of the two scenarios but leaves the decision process to go to 1998 KY26 for future reports. Rendezvous operations will be planned to detail the physical properties and surrounding environments of the target, one of the smallest elements of small planetary bodies. By achieving the planned operations, the mission will provide critical hints on the violent histories of collisions and accumulations of small bodies in the solar system. Furthermore, the established scientific knowledge and techniques will advance key technologies for planetary defense., Comment: 51 pages, 9 figures, and 10 tables. The article is in press in Advances in Space Research

Published
2021
Full Text
View/download PDF

3. Particle size distributions inside and around the artificial crater produced by the Hayabusa2 impact experiment on Ryugu

Author

Ogawa, K., Sakatani, N., Kadono, T., Arakawa, M., Honda, R., Wada, K., Shirai, K., Shimaki, Y., Ishibashi, K., Yokota, Y., Saiki, T., Imamura, H., Tsuda, Y., Nakazawa, S., Takagi, Y., Hayakawa, M., Yano, H., Okamoto, C., Iijima, Y., Morota, T., Kameda, S., Tatsumi, E., Cho, Y., Yoshioka, K., Sawada, H., Matsuoka, M., Yamada, M., Kouyama, T., Suzuki, H., Honda, C., and Sugita, S.

Published
2022
Full Text
View/download PDF

5. Anomalously porous boulders on (162173) Ryugu as primordial materials from its parent body

Author

Sakatani, N., Tanaka, S., Okada, T., Fukuhara, T., Riu, L., Sugita, S., Honda, R., Morota, T., Kameda, S., Yokota, Y., Tatsumi, E., Yumoto, K., Hirata, N., Miura, A., Kouyama, T., Senshu, H., Shimaki, Y., Arai, T., Takita, J., Demura, H., Sekiguchi, T., Müller, T. G., Hagermann, A., Biele, J., Grott, M., Hamm, M., Delbo, M., Neumann, W., Taguchi, M., Ogawa, Y., Matsunaga, T., Wada, T., Hasegawa, S., Helbert, J., Hirata, N., Noguchi, R., Yamada, M., Suzuki, H., Honda, C., Ogawa, K., Hayakawa, M., Yoshioka, K., Matsuoka, M., Cho, Y., Sawada, H., Kitazato, K., Iwata, T., Abe, M., Ohtake, M., Matsuura, S., Matsumoto, K., Noda, H., Ishihara, Y., Yamamoto, K., Higuchi, A., Namiki, N., Ono, G., Saiki, T., Imamura, H., Takagi, Y., Yano, H., Shirai, K., Okamoto, C., Nakazawa, S., Iijima, Y., Arakawa, M., Wada, K., Kadono, T., Ishibashi, K., Terui, F., Kikuchi, S., Yamaguchi, T., Ogawa, N., Mimasu, Y., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Takeuchi, H., Yamamoto, Y., Hirose, C., Hosoda, S., Mori, O., Shimada, T., Soldini, S., Tsukizaki, R., Ozaki, M., Tachibana, S., Ikeda, H., Ishiguro, M., Yabuta, H., Yoshikawa, M., Watanabe, S., and Tsuda, Y.

Published
2021
Full Text
View/download PDF

6. Thermally altered subsurface material of asteroid (162173) Ryugu

Author

Kitazato, K., Milliken, R. E., Iwata, T., Abe, M., Ohtake, M., Matsuura, S., Takagi, Y., Nakamura, T., Hiroi, T., Matsuoka, M., Riu, L., Nakauchi, Y., Tsumura, K., Arai, T., Senshu, H., Hirata, N., Barucci, M. A., Brunetto, R., Pilorget, C., Poulet, F., Bibring, J.-P., Domingue, D. L., Vilas, F., Takir, D., Palomba, E., Galiano, A., Perna, D., Osawa, T., Komatsu, M., Nakato, A., Arai, T., Takato, N., Matsunaga, T., Arakawa, M., Saiki, T., Wada, K., Kadono, T., Imamura, H., Yano, H., Shirai, K., Hayakawa, M., Okamoto, C., Sawada, H., Ogawa, K., Iijima, Y., Sugita, S., Honda, R., Morota, T., Kameda, S., Tatsumi, E., Cho, Y., Yoshioka, K., Yokota, Y., Sakatani, N., Yamada, M., Kouyama, T., Suzuki, H., Honda, C., Namiki, N., Mizuno, T., Matsumoto, K., Noda, H., Ishihara, Y., Yamada, R., Yamamoto, K., Yoshida, F., Abe, S., Higuchi, A., Yamamoto, Y., Okada, T., Shimaki, Y., Noguchi, R., Miura, A., Hirata, N., Tachibana, S., Yabuta, H., Ishiguro, M., Ikeda, H., Takeuchi, H., Shimada, T., Mori, O., Hosoda, S., Tsukizaki, R., Soldini, S., Ozaki, M., Terui, F., Ogawa, N., Mimasu, Y., Ono, G., Yoshikawa, K., Hirose, C., Fujii, A., Takahashi, T., Kikuchi, S., Takei, Y., Yamaguchi, T., Nakazawa, S., Tanaka, S., Yoshikawa, M., Watanabe, S., and Tsuda, Y.

Published
2021
Full Text
View/download PDF

7. Collisional history of Ryugu’s parent body from bright surface boulders

Author

Tatsumi, E., Sugimoto, C., Riu, L., Sugita, S., Nakamura, T., Hiroi, T., Morota, T., Popescu, M., Michikami, T., Kitazato, K., Matsuoka, M., Kameda, S., Honda, R., Yamada, M., Sakatani, N., Kouyama, T., Yokota, Y., Honda, C., Suzuki, H., Cho, Y., Ogawa, K., Hayakawa, M., Sawada, H., Yoshioka, K., Pilorget, C., Ishida, M., Domingue, D., Hirata, N., Sasaki, S., de León, J., Barucci, M. A., Michel, P., Suemitsu, M., Saiki, T., Tanaka, S., Terui, F., Nakazawa, S., Kikuchi, S., Yamaguchi, T., Ogawa, N., Ono, G., Mimasu, Y., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Yamamoto, Y., Okada, T., Hirose, C., Hosoda, S., Mori, O., Shimada, T., Soldini, S., Tsukizaki, R., Mizuno, T., Iwata, T., Yano, H., Ozaki, M., Abe, M., Ohtake, M., Namiki, N., Tachibana, S., Arakawa, M., Ikeda, H., Ishiguro, M., Wada, K., Yabuta, H., Takeuchi, H., Shimaki, Y., Shirai, K., Hirata, N., Iijima, Y., Tsuda, Y., Watanabe, S., and Yoshikawa, M.

Published
2021
Full Text
View/download PDF

8. Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Author

Nakamura, T., primary, Matsumoto, M., additional, Amano, K., additional, Enokido, Y., additional, Zolensky, M. E., additional, Mikouchi, T., additional, Genda, H., additional, Tanaka, S., additional, Zolotov, M. Y., additional, Kurosawa, K., additional, Wakita, S., additional, Hyodo, R., additional, Nagano, H., additional, Nakashima, D., additional, Takahashi, Y., additional, Fujioka, Y., additional, Kikuiri, M., additional, Kagawa, E., additional, Matsuoka, M., additional, Brearley, A. J., additional, Tsuchiyama, A., additional, Uesugi, M., additional, Matsuno, J., additional, Kimura, Y., additional, Sato, M., additional, Milliken, R. E., additional, Tatsumi, E., additional, Sugita, S., additional, Hiroi, T., additional, Kitazato, K., additional, Brownlee, D., additional, Joswiak, D. J., additional, Takahashi, M., additional, Ninomiya, K., additional, Takahashi, T., additional, Osawa, T., additional, Terada, K., additional, Brenker, F. E., additional, Tkalcec, B. J., additional, Vincze, L., additional, Brunetto, R., additional, Aléon-Toppani, A., additional, Chan, Q. H. S., additional, Roskosz, M., additional, Viennet, J.-C., additional, Beck, P., additional, Alp, E. E., additional, Michikami, T., additional, Nagaashi, Y., additional, Tsuji, T., additional, Ino, Y., additional, Martinez, J., additional, Han, J., additional, Dolocan, A., additional, Bodnar, R. J., additional, Tanaka, M., additional, Yoshida, H., additional, Sugiyama, K., additional, King, A. J., additional, Fukushi, K., additional, Suga, H., additional, Yamashita, S., additional, Kawai, T., additional, Inoue, K., additional, Nakato, A., additional, Noguchi, T., additional, Vilas, F., additional, Hendrix, A. R., additional, Jaramillo-Correa, C., additional, Domingue, D. L., additional, Dominguez, G., additional, Gainsforth, Z., additional, Engrand, C., additional, Duprat, J., additional, Russell, S. S., additional, Bonato, E., additional, Ma, C., additional, Kawamoto, T., additional, Wada, T., additional, Watanabe, S., additional, Endo, R., additional, Enju, S., additional, Riu, L., additional, Rubino, S., additional, Tack, P., additional, Takeshita, S., additional, Takeichi, Y., additional, Takeuchi, A., additional, Takigawa, A., additional, Takir, D., additional, Tanigaki, T., additional, Taniguchi, A., additional, Tsukamoto, K., additional, Yagi, T., additional, Yamada, S., additional, Yamamoto, K., additional, Yamashita, Y., additional, Yasutake, M., additional, Uesugi, K., additional, Umegaki, I., additional, Chiu, I., additional, Ishizaki, T., additional, Okumura, S., additional, Palomba, E., additional, Pilorget, C., additional, Potin, S. M., additional, Alasli, A., additional, Anada, S., additional, Araki, Y., additional, Sakatani, N., additional, Schultz, C., additional, Sekizawa, O., additional, Sitzman, S. D., additional, Sugiura, K., additional, Sun, M., additional, Dartois, E., additional, De Pauw, E., additional, Dionnet, Z., additional, Djouadi, Z., additional, Falkenberg, G., additional, Fujita, R., additional, Fukuma, T., additional, Gearba, I. R., additional, Hagiya, K., additional, Hu, M. Y., additional, Kato, T., additional, Kawamura, T., additional, Kimura, M., additional, Kubo, M. K., additional, Langenhorst, F., additional, Lantz, C., additional, Lavina, B., additional, Lindner, M., additional, Zhao, J., additional, Vekemans, B., additional, Baklouti, D., additional, Bazi, B., additional, Borondics, F., additional, Nagasawa, S., additional, Nishiyama, G., additional, Nitta, K., additional, Mathurin, J., additional, Matsumoto, T., additional, Mitsukawa, I., additional, Miura, H., additional, Miyake, A., additional, Miyake, Y., additional, Yurimoto, H., additional, Okazaki, R., additional, Yabuta, H., additional, Naraoka, H., additional, Sakamoto, K., additional, Tachibana, S., additional, Connolly, H. C., additional, Lauretta, D. S., additional, Yoshitake, M., additional, Yoshikawa, M., additional, Yoshikawa, K., additional, Yoshihara, K., additional, Yokota, Y., additional, Yogata, K., additional, Yano, H., additional, Yamamoto, Y., additional, Yamamoto, D., additional, Yamada, M., additional, Yamada, T., additional, Yada, T., additional, Wada, K., additional, Usui, T., additional, Tsukizaki, R., additional, Terui, F., additional, Takeuchi, H., additional, Takei, Y., additional, Iwamae, A., additional, Soejima, H., additional, Shirai, K., additional, Shimaki, Y., additional, Senshu, H., additional, Sawada, H., additional, Saiki, T., additional, Ozaki, M., additional, Ono, G., additional, Okada, T., additional, Ogawa, N., additional, Ogawa, K., additional, Noguchi, R., additional, Noda, H., additional, Nishimura, M., additional, Namiki, N., additional, Nakazawa, S., additional, Morota, T., additional, Miyazaki, A., additional, Miura, A., additional, Mimasu, Y., additional, Matsumoto, K., additional, Kumagai, K., additional, Kouyama, T., additional, Kikuchi, S., additional, Kawahara, K., additional, Kameda, S., additional, Iwata, T., additional, Ishihara, Y., additional, Ishiguro, M., additional, Ikeda, H., additional, Hosoda, S., additional, Honda, R., additional, Honda, C., additional, Hitomi, Y., additional, Hirata, N., additional, Hayashi, T., additional, Hayakawa, M., additional, Hatakeda, K., additional, Furuya, S., additional, Fukai, R., additional, Fujii, A., additional, Cho, Y., additional, Arakawa, M., additional, Abe, M., additional, and Tsuda, Y., additional

Published
2023
Full Text
View/download PDF

11. MASCOT radiometer reveals signs of strong aqueous alteration of (162173) Ryugu's materials

Author

Hamm, Maximilian, Grott, Matthias, Senshu, H., Knollenberg, Jörg, Wiljes, J. de, Hamilton, Victoria E., Scholten, Frank, Matz, K-D, Bates, H.C., Maturilli, Alessandro, Shimaki, Y., Sakatani, N., Neumann, Wladimir, Okada, T., Preusker, Frank, Elgner, Stephan, Helbert, Jörn, Kührt, Ekkehard, Ho, Tra-Mi, Tanaka, S., Jaumann, R., and Sugita, S.

Subjects
Hayabusa2 MASCOT MARA Radiometer Asteroid Ryugu Regolith
Published
2022

12. Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

Author

Tachibana, S., primary, Sawada, H., additional, Okazaki, R., additional, Takano, Y., additional, Sakamoto, K., additional, Miura, Y. N., additional, Okamoto, C., additional, Yano, H., additional, Yamanouchi, S., additional, Michel, P., additional, Zhang, Y., additional, Schwartz, S., additional, Thuillet, F., additional, Yurimoto, H., additional, Nakamura, T., additional, Noguchi, T., additional, Yabuta, H., additional, Naraoka, H., additional, Tsuchiyama, A., additional, Imae, N., additional, Kurosawa, K., additional, Nakamura, A. M., additional, Ogawa, K., additional, Sugita, S., additional, Morota, T., additional, Honda, R., additional, Kameda, S., additional, Tatsumi, E., additional, Cho, Y., additional, Yoshioka, K., additional, Yokota, Y., additional, Hayakawa, M., additional, Matsuoka, M., additional, Sakatani, N., additional, Yamada, M., additional, Kouyama, T., additional, Suzuki, H., additional, Honda, C., additional, Yoshimitsu, T., additional, Kubota, T., additional, Demura, H., additional, Yada, T., additional, Nishimura, M., additional, Yogata, K., additional, Nakato, A., additional, Yoshitake, M., additional, Suzuki, A. I., additional, Furuya, S., additional, Hatakeda, K., additional, Miyazaki, A., additional, Kumagai, K., additional, Okada, T., additional, Abe, M., additional, Usui, T., additional, Ireland, T. R., additional, Fujimoto, M., additional, Yamada, T., additional, Arakawa, M., additional, Connolly, H. C., additional, Fujii, A., additional, Hasegawa, S., additional, Hirata, N., additional, Hirose, C., additional, Hosoda, S., additional, Iijima, Y., additional, Ikeda, H., additional, Ishiguro, M., additional, Ishihara, Y., additional, Iwata, T., additional, Kikuchi, S., additional, Kitazato, K., additional, Lauretta, D. S., additional, Libourel, G., additional, Marty, B., additional, Matsumoto, K., additional, Michikami, T., additional, Mimasu, Y., additional, Miura, A., additional, Mori, O., additional, Nakamura-Messenger, K., additional, Namiki, N., additional, Nguyen, A. N., additional, Nittler, L. R., additional, Noda, H., additional, Noguchi, R., additional, Ogawa, N., additional, Ono, G., additional, Ozaki, M., additional, Senshu, H., additional, Shimada, T., additional, Shimaki, Y., additional, Shirai, K., additional, Soldini, S., additional, Takahashi, T., additional, Takei, Y., additional, Takeuchi, H., additional, Tsukizaki, R., additional, Wada, K., additional, Yamamoto, Y., additional, Yoshikawa, K., additional, Yumoto, K., additional, Zolensky, M. E., additional, Nakazawa, S., additional, Terui, F., additional, Tanaka, S., additional, Saiki, T., additional, Yoshikawa, M., additional, Watanabe, S., additional, and Tsuda, Y., additional

Published
2022
Full Text
View/download PDF

13. Additional file 1 of Effect of projectile shape and interior structure on crater size in strength regime

Author

Kadono, T., Arakawa, M., Tsujido, S., Yasui, M., Hasegawa, S., Kurosawa, K., Shirai, K., Okamoto, C., Ogawa, K., Iijima, Y., Shimaki, Y., and Wada, K.

Abstract

Additional file 1. Supporting materials for numerical simulations. Section S1. Analyses to obtain the profiles of peak pressure and particle velocity. Section S2. Procedure for low resolution calculations. Section S3. Equation of state for Nylon 66.

Published
2022
Full Text
View/download PDF

14. Additional file 1 of Particle size distributions inside and around the artificial crater produced by the Hayabusa2 impact experiment on Ryugu

Author

Ogawa, K., Sakatani, N., Kadono, T., Arakawa, M., Honda, R., Wada, K., Shirai, K., Shimaki, Y., Ishibashi, K., Yokota, Y., Saiki, T., Imamura, H., Tsuda, Y., Nakazawa, S., Takagi, Y., Hayakawa, M., Yano, H., Okamoto, C., Iijima, Y., Morota, T., Kameda, S., Tatsumi, E., Cho, Y., Yoshioka, K., Sawada, H., Matsuoka, M., Yamada, M., Kouyama, T., Suzuki, H., Honda, C., and Sugita, S.

Abstract

Additional file 1: Fig. S1. Overview of the slope around the SCI impact site.

Published
2022
Full Text
View/download PDF

15. Hayabusa2 extended mission: New voyage to rendezvous with a small asteroid rotating with a short period

Author

Hirabayashi, M., primary, Mimasu, Y., additional, Sakatani, N., additional, Watanabe, S., additional, Tsuda, Y., additional, Saiki, T., additional, Kikuchi, S., additional, Kouyama, T., additional, Yoshikawa, M., additional, Tanaka, S., additional, Nakazawa, S., additional, Takei, Y., additional, Terui, F., additional, Takeuchi, H., additional, Fujii, A., additional, Iwata, T., additional, Tsumura, K., additional, Matsuura, S., additional, Shimaki, Y., additional, Urakawa, S., additional, Ishibashi, Y., additional, Hasegawa, S., additional, Ishiguro, M., additional, Kuroda, D., additional, Okumura, S., additional, Sugita, S., additional, Okada, T., additional, Kameda, S., additional, Kamata, S., additional, Higuchi, A., additional, Senshu, H., additional, Noda, H., additional, Matsumoto, K., additional, Suetsugu, R., additional, Hirai, T., additional, Kitazato, K., additional, Farnocchia, D., additional, Naidu, S.P., additional, Tholen, D.J., additional, Hergenrother, C.W., additional, Whiteley, R.J., additional, Moskovitz, N.A., additional, and Abell, P.A., additional

Published
2021
Full Text
View/download PDF

16. Size of particles ejected from an artificial impact crater on asteroid 162173 Ryugu

Author

Wada, K., primary, Ishibashi, K., additional, Kimura, H., additional, Arakawa, M., additional, Sawada, H., additional, Ogawa, K., additional, Shirai, K., additional, Honda, R., additional, Iijima, Y., additional, Kadono, T., additional, Sakatani, N., additional, Mimasu, Y., additional, Toda, T., additional, Shimaki, Y., additional, Nakazawa, S., additional, Hayakawa, H., additional, Saiki, T., additional, Takagi, Y., additional, Imamura, H., additional, Okamoto, C., additional, Hayakawa, M., additional, Hirata, N., additional, and Yano, H., additional

Published
2021
Full Text
View/download PDF

17. Unprecedented mode of action of phenothiazines as ionophores unravelled by an NDH-2 bioelectrochemical assay platform

Author

Nakatani, Y, Shimaki, Y, Debajyoti, D, Muench, SP, Ireton, K, Cook, GM, and Jeuken, LJC

Abstract

Type II NADH:quinone oxidoreductase (NDH-2) plays a crucial role in the respiratory chains of many organisms. Its absence in mammalian cells makes NDH-2 an attractive new target for developing antimicrobials and anti-protozoal agents. We established a novel bioelectrochemical platform to characterize the catalytic behavior of NDH-2 from Caldalkalibacillus thermarum and Listeria monocytogenes strain EGD-e while bound to native-like lipid membranes. Catalysis of both NADH oxidation and lipophilic quinone reduction by membrane-bound NDH-2 followed the Michaelis–Menten model; however, the maximum turnover was only achieved when a high concentration of quinone (>3 mM) was present in the membrane, suggesting that quinone availability regulates NADH-coupled respiration activity. The quinone analogue 2-heptyl-4-hydroxyquinoline-N-oxide inhibited C. thermarum NDH-2 activity and its potency is higher in a membrane environment compared to assays performed with water-soluble quinone analogues, demonstrating the importance of testing compounds under physiologically relevant conditions. Furthermore, when phenothiazines, one of the most commonly identified NDH-2 inhibitors, were tested, they did not inhibit membrane-bound NDH-2. Instead, our assay platform unexpectedly suggests a novel mode of phenothiazine action where chlorpromazine, a promising anti-tubercular agent and key medicine used to treat psychotic disorders, is able to disrupt pH gradients across bacterial membranes.

Published
2020

18. Unveiling Highly-Porous Nature of Primitive Asteroid 162173 Ryugu by Thermal Imager on Hayabusa2

Author

Okada, T., Fukuhara, T., Tanaka, S., Taguchi, M., Arai, T., Sakatani, N., Shimaki, Y., Senshu, H., Ogawa, Y., Demura, H., Suko, K., Kitazato, K., Kouyama, T., Sekiguchi, T., Takita, J., Hasegawa, S., Matsunaga, T., Wada, T., Imamura, T., Helbert, Jörn, Mueller, T. G., Hagermann, A., Biele, Jens, Grott, Matthias, Hamm, Maximilian, Delbo, M, Yamamoto, Y., Hirata, N., Terui, F., Saiki, T., Nakazawa, S., Yoshikawa, M., Watanabe, S, and Tsuda, T.

Subjects
Planetenphysik, Planetare Labore, Ryugu, Hayabusa, Nutzerzentrum für Weltraumexperimente (MUSC), Asteroiden
Published
2020

19. Collisional history of Ryugu’s parent body from bright surface boulders

Author

Tatsumi, E., primary, Sugimoto, C., additional, Riu, L., additional, Sugita, S., additional, Nakamura, T., additional, Hiroi, T., additional, Morota, T., additional, Popescu, M., additional, Michikami, T., additional, Kitazato, K., additional, Matsuoka, M., additional, Kameda, S., additional, Honda, R., additional, Yamada, M., additional, Sakatani, N., additional, Kouyama, T., additional, Yokota, Y., additional, Honda, C., additional, Suzuki, H., additional, Cho, Y., additional, Ogawa, K., additional, Hayakawa, M., additional, Sawada, H., additional, Yoshioka, K., additional, Pilorget, C., additional, Ishida, M., additional, Domingue, D., additional, Hirata, N., additional, Sasaki, S., additional, de León, J., additional, Barucci, M. A., additional, Michel, P., additional, Suemitsu, M., additional, Saiki, T., additional, Tanaka, S., additional, Terui, F., additional, Nakazawa, S., additional, Kikuchi, S., additional, Yamaguchi, T., additional, Ogawa, N., additional, Ono, G., additional, Mimasu, Y., additional, Yoshikawa, K., additional, Takahashi, T., additional, Takei, Y., additional, Fujii, A., additional, Yamamoto, Y., additional, Okada, T., additional, Hirose, C., additional, Hosoda, S., additional, Mori, O., additional, Shimada, T., additional, Soldini, S., additional, Tsukizaki, R., additional, Mizuno, T., additional, Iwata, T., additional, Yano, H., additional, Ozaki, M., additional, Abe, M., additional, Ohtake, M., additional, Namiki, N., additional, Tachibana, S., additional, Arakawa, M., additional, Ikeda, H., additional, Ishiguro, M., additional, Wada, K., additional, Yabuta, H., additional, Takeuchi, H., additional, Shimaki, Y., additional, Shirai, K., additional, Iijima, Y., additional, Tsuda, Y., additional, Watanabe, S., additional, and Yoshikawa, M., additional

Published
2020
Full Text
View/download PDF

20. Sample collection from asteroid (162173) Ryugu by Hayabusa2: Implications for surface evolution

Author

Morota, T., primary, Sugita, S., additional, Cho, Y., additional, Kanamaru, M., additional, Tatsumi, E., additional, Sakatani, N., additional, Honda, R., additional, Hirata, N., additional, Kikuchi, H., additional, Yamada, M., additional, Yokota, Y., additional, Kameda, S., additional, Matsuoka, M., additional, Sawada, H., additional, Honda, C., additional, Kouyama, T., additional, Ogawa, K., additional, Suzuki, H., additional, Yoshioka, K., additional, Hayakawa, M., additional, Hirabayashi, M., additional, Miyamoto, H., additional, Michikami, T., additional, Hiroi, T., additional, Hemmi, R., additional, Barnouin, O. S., additional, Ernst, C. M., additional, Kitazato, K., additional, Nakamura, T., additional, Riu, L., additional, Senshu, H., additional, Kobayashi, H., additional, Sasaki, S., additional, Komatsu, G., additional, Tanabe, N., additional, Fujii, Y., additional, Irie, T., additional, Suemitsu, M., additional, Takaki, N., additional, Sugimoto, C., additional, Yumoto, K., additional, Ishida, M., additional, Kato, H., additional, Moroi, K., additional, Domingue, D., additional, Michel, P., additional, Pilorget, C., additional, Iwata, T., additional, Abe, M., additional, Ohtake, M., additional, Nakauchi, Y., additional, Tsumura, K., additional, Yabuta, H., additional, Ishihara, Y., additional, Noguchi, R., additional, Matsumoto, K., additional, Miura, A., additional, Namiki, N., additional, Tachibana, S., additional, Arakawa, M., additional, Ikeda, H., additional, Wada, K., additional, Mizuno, T., additional, Hirose, C., additional, Hosoda, S., additional, Mori, O., additional, Shimada, T., additional, Soldini, S., additional, Tsukizaki, R., additional, Yano, H., additional, Ozaki, M., additional, Takeuchi, H., additional, Yamamoto, Y., additional, Okada, T., additional, Shimaki, Y., additional, Shirai, K., additional, Iijima, Y., additional, Noda, H., additional, Kikuchi, S., additional, Yamaguchi, T., additional, Ogawa, N., additional, Ono, G., additional, Mimasu, Y., additional, Yoshikawa, K., additional, Takahashi, T., additional, Takei, Y., additional, Fujii, A., additional, Nakazawa, S., additional, Terui, F., additional, Tanaka, S., additional, Yoshikawa, M., additional, Saiki, T., additional, Watanabe, S., additional, and Tsuda, Y., additional

Published
2020
Full Text
View/download PDF

21. An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

Author

Arakawa, M., primary, Saiki, T., additional, Wada, K., additional, Ogawa, K., additional, Kadono, T., additional, Shirai, K., additional, Sawada, H., additional, Ishibashi, K., additional, Honda, R., additional, Sakatani, N., additional, Iijima, Y., additional, Okamoto, C., additional, Yano, H., additional, Takagi, Y., additional, Hayakawa, M., additional, Michel, P., additional, Jutzi, M., additional, Shimaki, Y., additional, Kimura, S., additional, Mimasu, Y., additional, Toda, T., additional, Imamura, H., additional, Nakazawa, S., additional, Hayakawa, H., additional, Sugita, S., additional, Morota, T., additional, Kameda, S., additional, Tatsumi, E., additional, Cho, Y., additional, Yoshioka, K., additional, Yokota, Y., additional, Matsuoka, M., additional, Yamada, M., additional, Kouyama, T., additional, Honda, C., additional, Tsuda, Y., additional, Watanabe, S., additional, Yoshikawa, M., additional, Tanaka, S., additional, Terui, F., additional, Kikuchi, S., additional, Yamaguchi, T., additional, Ogawa, N., additional, Ono, G., additional, Yoshikawa, K., additional, Takahashi, T., additional, Takei, Y., additional, Fujii, A., additional, Takeuchi, H., additional, Yamamoto, Y., additional, Okada, T., additional, Hirose, C., additional, Hosoda, S., additional, Mori, O., additional, Shimada, T., additional, Soldini, S., additional, Tsukizaki, R., additional, Iwata, T., additional, Ozaki, M., additional, Abe, M., additional, Namiki, N., additional, Kitazato, K., additional, Tachibana, S., additional, Ikeda, H., additional, Hirata, N., additional, Noguchi, R., additional, and Miura, A., additional

Published
2020
Full Text
View/download PDF

22. Fine-grained region with low thermal inertia in craters on Ryugu

Author

Sakatani, N., Tanaka, S., Okada, T., Senshu, H., Arai, T., Demura, H., Suko, K., Shimaki, Y., Sekiguchi, Tomohiko, Takita, J., Fuhuhara, T., Tagucchi, M., Müller, T., Hagermann, A., Biele, Jens, Grott, Matthias, Hamm, Maximilian, Delbo, M, Sugita, Seiji, Honda, R., Morota, T., Yamada, M., Kameda, S., Tatsumi, E., Yokota, Y., Kouyama, Toru, Suzuki, H., Honda, C., Ogawa, Kazunori, Hayakawa, M., Yoshioka, K., Matsuoka, A., Cho, Yuichiro, Sawada, H., and Miuara, A.

Subjects
Planetenphysik, Hayabusa2 Ryugu, Nutzerzentrum für Weltraumexperimente (MUSC)
Abstract

Introduction: The Hayabusa2 spacecraft is surveying asteroid Ryugu from June 2018. Global observation by thermal infrared imager TIR revealed low thermal inertia around 200-300J m-2 K-1 s-0.5 [1]. The expected grain size from this thermal inertia was several centimeters [2]. However, the surface of Ryugu is globally filled with larger boulders [3]. These observational results indicate highly porous nature of the surface boulders with low thermal inertia, unexpectedly different from the carbonaceous meteorites we have. Local observations by MARA radiometer onboard MASCOT lander supported it [4, 5]. In addition to the global observation, close-up imaging by TIR during descending operations, including MINERVA and MASCOT releases, touch-down operations and their rehearsals, were conducted. The high resolution TIR images revealed local temperature anomaly related to the boulders [6] and craters, which showed local variation in thermophysical properties.In this study, we show survey of thermally-unusual craters on Ryugu using these close-up images. The unique feature were found as hot spot around the center of some small craters.

Published
2019

23. Spectral Characteristics of Asteroid (162173) Ryugu with Hayabusa2 NIRS3

Author

Takir, D., Kitazato, K., Milliken, R. E., Iwata, T., Abe, M., Ohtake, M., Matsuura, S., Nakauchi, Y., Nakamura, T., Matsuoka, M., Senshu, H., Hiroi, T., Pilorget, C., Brunetto, R., Poulet, F., Riu, L., Bibring, J.-P., Domingue, D. L., Vilas, F., Barucci, M. A., Perna, D., Palomba, E., Galiano, A., Tsumura, K., Osawa, T., Komatsu, M., Nakato, A., Arai, T., Takato, N., Matsunaga, T., Takagi, Y., Matsumoto, K., Kouyama, T., Yokota, Y., Tatsumi, E., Sakatani, N., Yamamoto, Y., Okada, T., Sugita, S., Honda, R., Morota, T., Kameda, S., Sawada, H., Honda, C., Yamada, M., Suzuki, H., Yoshioka, K., Hayakawa, M., Ogawa, K., Cho, Y., Shirai, K., Shimaki, Y., Hirata, N., Yamaguchi, A., Ogawa, N., Terui, F., Yamaguchi, T., Takei, Y., SAIKI, T., Nakazawa, S., Tanaka, S., Yoshikawa, M., Watanabe, S., Tsuda, Y., Department of Geological Sciences [Providence], Brown University, Department of Environmental and Materials Engineering, Nagoya Institute, Graduate School of Science and Engineering, Tokyo Metropolitan University [Tokyo] (TMU), RIKEN Nishina Center for Accelerator-Based Science [Wako] (RIKEN RNC), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Tsukuba Space Center (TKSC), Japan Aerospace Exploration Agency [Tokyo] (JAXA), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), GEOMA, Université de Vigo, Universidade de Vigo, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Department of Physics, Tokyo, Waseda University, IHP Microelctronics, Institute of Ecology, Tallinn University-Tallinn University, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Department of Applied Physics, The University of Tokyo (UTokyo), University of Electro-Communications [Tokyo] (UEC), Stanford Synchrotron Radiation Lightsource (SSRL SLAC), SLAC National Accelerator Laboratory (SLAC), Stanford University-Stanford University, Antarctic Meteorite Research Center, National Institute of Polar Research [Tokyo] (NiPR), Advanced Materials Institute and Department of Chemistry, Fukuoka University, Department of Electronics and Electrical Engineering, Faculty of Science and Technology, Keio University, Institute for Research on Earth Evolution [Yokosuka] (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Plasma Research Center, Université de Tsukuba = University of Tsukuba, Tokyo Metropolitan University [Tokyo], RIKEN Nishina Center (for Accelerator-Based Science), Universidate de Vigo, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), The University of Tokyo, Stanford Synchrotron Radiation Laboratory (SSRL), Stanford Linear Accelerator Center, and University of Tsukuba

Subjects
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract

International audience; We report recent results of the surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy .

Published
2019

24. Surface physical condition of asteroid Ryugu using close-up optical and thermal images

Author

Sakatani, N., Sugita, S., Honda, R., Morota, T., Yamada, M., Kameda, Shingo, Tatsumi, E., Yokota, S., Kouyama, T., Suzuki, H., Honda, C., Hayakawa, M., Yoshioka, K., Matsuoko, Moe, Cho, Y., Sawada, H., Ogawa, N., Miura, A., Okada, T., Tanaka, S., Senshu, H., Arai, T., Demura, Hirohide, Suko, K., Shimaki, Y., Sekigucchi, T., Takita, J., Fuhuhara, T., Tagutchi, M., Müller, T., Hagermann, A., Biele, Jens, Grott, Matthias, and Delbo, M.

Subjects
Hayabusa 2, Planetenphysik, Ryugu, Nutzerzentrum für Weltraumexperimente (MUSC)
Abstract

In 2018, the Hayabusa2 spacecraft [1] successfully conducted some descend operations toward Ryugu’s surface. They included MINERVA rover release in September, MASCOT lander release and two touchdown rehearsals in October. During these operations, we acquired high-resolved optical and thermal images from altitudes below 100 m, us- ing Optical Navigation Camera (ONC-T) and Ther- mal Infrared Imager (TIR), respectively. Close-up optical images by ONC-T show detailed physical conditions of the surface materials, such as particle size distribution of pebbles, surface morphol- ogy of small boulders and craters. Moreover, close-up thermal images by TIR indicate thermophysical prop- erties of the surface materials and its regional differ- ence, which cannot be resolved by higher altitude observations (e.g., home-position observations from 20 km altitude). Combination between optical and thermal observations is of great importance to under- stand the nature of the asteroid surface materials. In this study, we investigate the surface particle size from close-up ONC images. Thermophysical property of the surface component materials inferred from TIR images is also discussed, especially for the range observed for the thermal inertia of boulders.

Published
2019

25. Thermal Inertia of C-Type Near-Earth Asteroid 162173 Ryugu Determined from the Dawn Side Observations by Thermal Infrared Imager

Author

Okada, T., Fukuhara, T., Tanaka, S., Taguchi, M., Arai, T., Sakatani, N., Shimaki, Y., Senshu, H., Demura, H., Ogawa, Y., Suko, K., Sekiguchi, T., Kouyama, T., Helbert, Jörn, Mueller, T. G., Hagermann, A., Biele, Jens, Grott, Matthias, Hamm, Maximilian, and Delbo, Marco

Subjects
Planetenphysik, Thermal Infrared Imager, Thermal, Asteroid, Leitungsbereich PF, Ryugu, Inertia C Type, NEO, Nutzerzentrum für Weltraumexperimente (MUSC)
Published
2019

26. High Porosity Nature of the Top-Shape C-Type Asteroid 162173 Ryugu as Observed by Hayabusa2

Author

Watanabe, S, Hirabayashi, M., Hirata, N., Shimaki, Y., Ikeda, H., Tatsumi, E., Yoshikawa, M., Kikuchi, S., Yabuta, H., Nakamura, T., Tachibana, S., Ishihara, Y., Morota, T., Kitazato, K., Sakatani, N., Matsumoto, K., Wada, Koji, Senshu, H., Honda, C., Michikami, T., Takeuchi, H., Kouyama, T., Honda, R., Kameda, S., Fuse, T., Miyamoto, H., Komatsu, G., Sugita, S., Okada, T., Namiki, N., Arakawa, M., Ishiguro, M., Abe, M., Gaskell, R., Palmer, E., Barnouin, O.S., Michel, P., French, A. S.V, McMahon, J. W., Scheeres, D. J., Abell, P. A., Yamamoto, Y., Tanaka, S., Shirai, K., Matsuoka, M., Yamada, M., Yokota, Y., Suzuki, H., Yoshioka, K., Cho, Y., Nishikawa, N., Sugiyama, T., Kikuchi, H., Hemmi, R., Yamaguchi, T., Ogawa, N., Ono, G., Mimasu, Y., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Hirose, C., Iwata, T., Hayakawa, M., Hosoda, S., Mori, O., Sawada, H., Shimada, T., Soldini, S., Yano, H., Tsukizaki, R., Ozaki, H., Iijima, Y., Ogawa, K., Fujimoto, M., Ho, T.-M., Moussi-Soffys, A., Jaumann, R, Bibring, J-.P., Krause, Christian, Terui, F., Saiki, T., Nakazawa, S., and Tsuda, Y.

Subjects
Planetengeologie, Asteroid, Systementwicklung und Projektbüro, Ryugu, Nutzerzentrum für Weltraumexperimente (MUSC), Hayabusa2
Published
2019

27. Thermal Imaging of C-Type Near Earth Asteroid 162173 Ryugu by Thermal Imfrared Imager TIR on Hayabusa2

Author

Okada, T., Fukuhara, T., Tanaka, S., Taguchi, M., Arai, T., Sakatani, N., Shimaki, Y., Senshu, H., Ogawa, Y., Demura, H., Suko, K., Kitazato, K., Kouyama, T., Sekiguchi, T., Takita, J., Hasegawa, S., Matsunaga, T., Wada, T., Imamura, T., Helbert, Jörn, Mueller, T. G., Hagermann, A., Biele, Jens, Grott, Matthias, Hamm, Maximilian, Delbo, Marco, Yamamoto, Y., Hirata, N., Saiki, T., Terui, F., Nakazawa, S., Yoshikawa, M., Watanabe, S, and Tsuda, Y.

Subjects
TIR, Planetenphysik, Thermal, Leitungsbereich PF, Ryugu, C-Type Asteroid, Thermal Imaging, NEO, Infrared Imager, Nutzerzentrum für Weltraumexperimente (MUSC), Hayabusa2
Published
2019

28. Hypervelocity collision and water-rock interaction in space preserved in the Chelyabinsk ordinary chondrite

Author

Nakamura, E., Kunihiro, T., Ota, T., Sakaguchi, C., Tanaka, R., Kitagawa, H., Kobayashi, K., Yamanaka, M., Shimaki, Y., Bebout, G. E., Miura, H., Yamamoto, T., Malkovets, V., Grokhovsky, V., Koroleva, O., Litasov, K., Nakamura, E., Kunihiro, T., Ota, T., Sakaguchi, C., Tanaka, R., Kitagawa, H., Kobayashi, K., Yamanaka, M., Shimaki, Y., Bebout, G. E., Miura, H., Yamamoto, T., Malkovets, V., Grokhovsky, V., Koroleva, O., and Litasov, K.

Abstract

A comprehensive geochemical study of the Chelyabinsk meteorite reveals further details regarding its history of impact-related fragmentation and melting, and later aqueous alteration, during its transit toward Earth. We support an 930Ma age obtained by Ar-Ar method (Beard et al., 2014) for the impact-related melting, based on Rb-Sr isotope analyses of a melt domain. An irregularly shaped olivine with a distinct O isotope composition in a melt domain appears to be a fragment of a silicate-rich impactor. Hydrogen and Li concentrations and isotopic compositions, textures of Fe oxyhydroxides, and the presence of organic materials located in fractures, are together consistent with aqueous alteration, and this alteration could have pre-dated interaction with the Earth's atmosphere. As one model, we suggest that hypervelocity capture of the impact-related debris by a comet nucleus could have led to shock-wave-induced supercritical aqueous fluids dissolving the silicate, metallic, and organic matter, with later ice sublimation yielding a rocky rubble pile sampled by the meteorite. © 2019 The Japan Academy.

Published
2019

29. The surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy

Author

Kitazato, K., primary, Milliken, R. E., additional, Iwata, T., additional, Abe, M., additional, Ohtake, M., additional, Matsuura, S., additional, Arai, T., additional, Nakauchi, Y., additional, Nakamura, T., additional, Matsuoka, M., additional, Senshu, H., additional, Hirata, N., additional, Hiroi, T., additional, Pilorget, C., additional, Brunetto, R., additional, Poulet, F., additional, Riu, L., additional, Bibring, J.-P., additional, Takir, D., additional, Domingue, D. L., additional, Vilas, F., additional, Barucci, M. A., additional, Perna, D., additional, Palomba, E., additional, Galiano, A., additional, Tsumura, K., additional, Osawa, T., additional, Komatsu, M., additional, Nakato, A., additional, Takato, N., additional, Matsunaga, T., additional, Takagi, Y., additional, Matsumoto, K., additional, Kouyama, T., additional, Yokota, Y., additional, Tatsumi, E., additional, Sakatani, N., additional, Yamamoto, Y., additional, Okada, T., additional, Sugita, S., additional, Honda, R., additional, Morota, T., additional, Kameda, S., additional, Sawada, H., additional, Honda, C., additional, Yamada, M., additional, Suzuki, H., additional, Yoshioka, K., additional, Hayakawa, M., additional, Ogawa, K., additional, Cho, Y., additional, Shirai, K., additional, Shimaki, Y., additional, Yamaguchi, A., additional, Ogawa, N., additional, Terui, F., additional, Yamaguchi, T., additional, Takei, Y., additional, Saiki, T., additional, Nakazawa, S., additional, Tanaka, S., additional, Yoshikawa, M., additional, Watanabe, S., additional, and Tsuda, Y., additional

Published
2019
Full Text
View/download PDF

30. The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

Author

Sugita, S., primary, Honda, R., additional, Morota, T., additional, Kameda, S., additional, Sawada, H., additional, Tatsumi, E., additional, Yamada, M., additional, Honda, C., additional, Yokota, Y., additional, Kouyama, T., additional, Sakatani, N., additional, Ogawa, K., additional, Suzuki, H., additional, Okada, T., additional, Namiki, N., additional, Tanaka, S., additional, Iijima, Y., additional, Yoshioka, K., additional, Hayakawa, M., additional, Cho, Y., additional, Matsuoka, M., additional, Hirata, N., additional, Miyamoto, H., additional, Domingue, D., additional, Hirabayashi, M., additional, Nakamura, T., additional, Hiroi, T., additional, Michikami, T., additional, Michel, P., additional, Ballouz, R.-L., additional, Barnouin, O. S., additional, Ernst, C. M., additional, Schröder, S. E., additional, Kikuchi, H., additional, Hemmi, R., additional, Komatsu, G., additional, Fukuhara, T., additional, Taguchi, M., additional, Arai, T., additional, Senshu, H., additional, Demura, H., additional, Ogawa, Y., additional, Shimaki, Y., additional, Sekiguchi, T., additional, Müller, T. G., additional, Hagermann, A., additional, Mizuno, T., additional, Noda, H., additional, Matsumoto, K., additional, Yamada, R., additional, Ishihara, Y., additional, Ikeda, H., additional, Araki, H., additional, Yamamoto, K., additional, Abe, S., additional, Yoshida, F., additional, Higuchi, A., additional, Sasaki, S., additional, Oshigami, S., additional, Tsuruta, S., additional, Asari, K., additional, Tazawa, S., additional, Shizugami, M., additional, Kimura, J., additional, Otsubo, T., additional, Yabuta, H., additional, Hasegawa, S., additional, Ishiguro, M., additional, Tachibana, S., additional, Palmer, E., additional, Gaskell, R., additional, Le Corre, L., additional, Jaumann, R., additional, Otto, K., additional, Schmitz, N., additional, Abell, P. A., additional, Barucci, M. A., additional, Zolensky, M. E., additional, Vilas, F., additional, Thuillet, F., additional, Sugimoto, C., additional, Takaki, N., additional, Suzuki, Y., additional, Kamiyoshihara, H., additional, Okada, M., additional, Nagata, K., additional, Fujimoto, M., additional, Yoshikawa, M., additional, Yamamoto, Y., additional, Shirai, K., additional, Noguchi, R., additional, Ogawa, N., additional, Terui, F., additional, Kikuchi, S., additional, Yamaguchi, T., additional, Oki, Y., additional, Takao, Y., additional, Takeuchi, H., additional, Ono, G., additional, Mimasu, Y., additional, Yoshikawa, K., additional, Takahashi, T., additional, Takei, Y., additional, Fujii, A., additional, Hirose, C., additional, Nakazawa, S., additional, Hosoda, S., additional, Mori, O., additional, Shimada, T., additional, Soldini, S., additional, Iwata, T., additional, Abe, M., additional, Yano, H., additional, Tsukizaki, R., additional, Ozaki, M., additional, Nishiyama, K., additional, Saiki, T., additional, Watanabe, S., additional, and Tsuda, Y., additional

Published
2019
Full Text
View/download PDF

31. Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu—A spinning top–shaped rubble pile

Author

Watanabe, S., primary, Hirabayashi, M., additional, Hirata, N., additional, Hirata, Na., additional, Noguchi, R., additional, Shimaki, Y., additional, Ikeda, H., additional, Tatsumi, E., additional, Yoshikawa, M., additional, Kikuchi, S., additional, Yabuta, H., additional, Nakamura, T., additional, Tachibana, S., additional, Ishihara, Y., additional, Morota, T., additional, Kitazato, K., additional, Sakatani, N., additional, Matsumoto, K., additional, Wada, K., additional, Senshu, H., additional, Honda, C., additional, Michikami, T., additional, Takeuchi, H., additional, Kouyama, T., additional, Honda, R., additional, Kameda, S., additional, Fuse, T., additional, Miyamoto, H., additional, Komatsu, G., additional, Sugita, S., additional, Okada, T., additional, Namiki, N., additional, Arakawa, M., additional, Ishiguro, M., additional, Abe, M., additional, Gaskell, R., additional, Palmer, E., additional, Barnouin, O. S., additional, Michel, P., additional, French, A. S., additional, McMahon, J. W., additional, Scheeres, D. J., additional, Abell, P. A., additional, Yamamoto, Y., additional, Tanaka, S., additional, Shirai, K., additional, Matsuoka, M., additional, Yamada, M., additional, Yokota, Y., additional, Suzuki, H., additional, Yoshioka, K., additional, Cho, Y., additional, Nishikawa, N., additional, Sugiyama, T., additional, Kikuchi, H., additional, Hemmi, R., additional, Yamaguchi, T., additional, Ogawa, N., additional, Ono, G., additional, Mimasu, Y., additional, Yoshikawa, K., additional, Takahashi, T., additional, Takei, Y., additional, Fujii, A., additional, Hirose, C., additional, Iwata, T., additional, Hayakawa, M., additional, Hosoda, S., additional, Mori, O., additional, Sawada, H., additional, Shimada, T., additional, Soldini, S., additional, Yano, H., additional, Tsukizaki, R., additional, Ozaki, M., additional, Iijima, Y., additional, Ogawa, K., additional, Fujimoto, M., additional, Ho, T.-M., additional, Moussi, A., additional, Jaumann, R., additional, Bibring, J.-P., additional, Krause, C., additional, Terui, F., additional, Saiki, T., additional, Nakazawa, S., additional, and Tsuda, Y., additional

Published
2019
Full Text
View/download PDF

34. FINE-GRAINED REGION WITH LOW THERMAL INERTIA IN CRATERS ON RYUGU.

Author

Sakatani, N., Tanaka, S., Okada, T., Senshu, H., Arai, T., Demura, H., Suko, K., Shimaki, Y., Sekiguchi, T., Takita, J., Fuhuhara, T., Taguchi, M., Müller, T., Hagermann, A., Biele, J., Grott, M., Hamm, M., Delbo, M., Sugita, S., and Honda, R.

Subjects
GRANTS in aid (Public finance), LUNAR craters, LUNAR soil, HIGH resolution imaging
Published
2021

35. THERMOPHYSICAL PROPERTIES OF ASTEROID 162173 RYUGU REVEALED BY HIGH-RESOLVED THERMAL IMAGING - A LINK TO POROUS ASTEROID FORMATION.

Author

Okada, T., Fukuhara, T., Tanaka, S., Taguchi, M., Arai, T., Sakatani, N., Shimaki, Y., Senshu, H., Ogawa, Y., Demura, H., Suko, K., Kitazato, K., Kouyama, T., Sekiguchi, T., Takita, J., Hasegawa, S., Matsunaga, T., Wada, T., Imamura, T., and Helbert, J.

Subjects
THERMOGRAPHY, THERMOPHYSICAL properties, NEAR-earth asteroids, ASTEROIDS, PLANETARY science, INFRARED imaging
Published
2021

36. SPACE IMPACT EXPERIMENT ON RYUGU: EJECTA CURTAIN OBSERVED BY DCAM3.

Author

Ogawa, K., Arakawa, M., Shirai, K., Sawada, H., Honda, R., Ishibashi, K., Wada, K., Kadono, T., Iijima, Y., Sakatani, N., Shimaki, Y., Mimasu, Y., Toda, T., Nakazawa, S., Hayakawa, H., Saiki, T., Takagi, Y., Imamura, H., Okamoto, C., and Yano, H.

Subjects
DRAPERIES, CYLINDER (Shapes), PLANETARY science
Published
2021

37. SPACE IMPACT EXPERIMENT ON RYUGU: ARTIFICIAL CRATER.

Author

Kadono, T., Arakawa, M., Wada, K., Shirai, K., Ogawa, K., Sakatani, N., Ishibashi, K., Shimaki, Y., Takagi, Y., Yano, H., Okamoto, C., Hayakawa, M., Saiki, T., Sawada, H., Imamura, H., Nakazawa, S., Iijima, Y., Honda, R., and Sugita, S.

Subjects
IMPACT craters, LUNAR craters, NEAR-earth asteroids, METEORITE craters, PLANETARY science, CYLINDER (Shapes), DYNAMIC pressure
Published
2021

38. SHAPE RECONSTRUCTION OF THE ASTEROID RYUGU IN HAYABUSA2 MISSION.

Author

Hirata, Naru, Naoyuki Hirata, Tanaka, S., Nishikawa, N., Sugiyama, T., Noguchi, R., Shimaki, Y., Gaskell, R., Palmer, E., Matsumoto, K., Senshu, H., Yamamoto, Y., Murakami, S., Ishihara, Y., Sugita, S., Morota, T., Honda, R., Arakawa, M., Ogawa, K., and Tsuda, Y.

Subjects
ASTEROIDS, CHURYUMOV-Gerasimenko comet, DIGITAL elevation models, PLANETARY science, HIGH resolution imaging
Published
2021

41. An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

Author

Arakawa, M., Saiki, T., Wada, K., Ogawa, K., Kadono, T., Shirai, K., Sawada, H., Ishibashi, K., Honda, R., Sakatani, N., Iijima, Y., Okamoto, C., Yano, H., Takagi, Y., Hayakawa, M., Michel, P., Jutzi, M., Shimaki, Y., Kimura, S., Mimasu, Y., Toda, T., Imamura, H., Nakazawa, S., Hayakawa, H., Sugita, S., Morota, T., Kameda, S., Tatsumi, E., Cho, Y., Yoshioka, K., Yokota, Y., Matsuoka, M., Yamada, M., Kouyama, T., Honda, C., Tsuda, Y., Watanabe, S., Yoshikawa, M., Tanaka, S., Terui, F., Kikuchi, S., Yamaguchi, T., Ogawa, N., Ono, G., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Takeuchi, H., Yamamoto, Y., Okada, T., Hirose, C., Hosoda, S., Mori, O., Shimada, T., Soldini, S., Tsukizaki, R., Iwata, T., Ozaki, M., Abe, M., Namiki, N., Kitazato, K., Tachibana, S., Ikeda, H., Hirata, N., Noguchi, R., and Miura, A.

Subjects
13. Climate action, 520 Astronomy, 620 Engineering
Abstract

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2’s Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu’s surface age.

42. Soluble organic molecules in samples of the carbonaceous asteroid (162173) Ryugu.

Author

Naraoka H, Takano Y, Dworkin JP, Oba Y, Hamase K, Furusho A, Ogawa NO, Hashiguchi M, Fukushima K, Aoki D, Schmitt-Kopplin P, Aponte JC, Parker ET, Glavin DP, McLain HL, Elsila JE, Graham HV, Eiler JM, Orthous-Daunay FR, Wolters C, Isa J, Vuitton V, Thissen R, Sakai S, Yoshimura T, Koga T, Ohkouchi N, Chikaraishi Y, Sugahara H, Mita H, Furukawa Y, Hertkorn N, Ruf A, Yurimoto H, Nakamura T, Noguchi T, Okazaki R, Yabuta H, Sakamoto K, Tachibana S, Connolly HC Jr, Lauretta DS, Abe M, Yada T, Nishimura M, Yogata K, Nakato A, Yoshitake M, Suzuki A, Miyazaki A, Furuya S, Hatakeda K, Soejima H, Hitomi Y, Kumagai K, Usui T, Hayashi T, Yamamoto D, Fukai R, Kitazato K, Sugita S, Namiki N, Arakawa M, Ikeda H, Ishiguro M, Hirata N, Wada K, Ishihara Y, Noguchi R, Morota T, Sakatani N, Matsumoto K, Senshu H, Honda R, Tatsumi E, Yokota Y, Honda C, Michikami T, Matsuoka M, Miura A, Noda H, Yamada T, Yoshihara K, Kawahara K, Ozaki M, Iijima YI, Yano H, Hayakawa M, Iwata T, Tsukizaki R, Sawada H, Hosoda S, Ogawa K, Okamoto C, Hirata N, Shirai K, Shimaki Y, Yamada M, Okada T, Yamamoto Y, Takeuchi H, Fujii A, Takei Y, Yoshikawa K, Mimasu Y, Ono G, Ogawa N, Kikuchi S, Nakazawa S, Terui F, Tanaka S, Saiki T, Yoshikawa M, Watanabe SI, and Tsuda Y

Abstract

The Hayabusa2 spacecraft collected samples from the surface of the carbonaceous near-Earth asteroid (162173) Ryugu and brought them to Earth. The samples were expected to contain organic molecules, which record processes that occurred in the early Solar System. We analyzed organic molecules extracted from the Ryugu surface samples. We identified a variety of molecules containing the atoms CHNOS, formed by methylation, hydration, hydroxylation, and sulfurization reactions. Amino acids, aliphatic amines, carboxylic acids, polycyclic aromatic hydrocarbons, and nitrogen-heterocyclic compounds were detected, which had properties consistent with an abiotic origin. These compounds likely arose from an aqueous reaction on Ryugu's parent body and are similar to the organics in Ivuna-type meteorites. These molecules can survive on the surfaces of asteroids and be transported throughout the Solar System.

Published
2023
Full Text
View/download PDF

43. Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution.

Author

Okazaki R, Marty B, Busemann H, Hashizume K, Gilmour JD, Meshik A, Yada T, Kitajima F, Broadley MW, Byrne D, Füri E, Riebe MEI, Krietsch D, Maden C, Ishida A, Clay P, Crowther SA, Fawcett L, Lawton T, Pravdivtseva O, Miura YN, Park J, Bajo KI, Takano Y, Yamada K, Kawagucci S, Matsui Y, Yamamoto M, Righter K, Sakai S, Iwata N, Shirai N, Sekimoto S, Inagaki M, Ebihara M, Yokochi R, Nishiizumi K, Nagao K, Lee JI, Kano A, Caffee MW, Uemura R, Nakamura T, Naraoka H, Noguchi T, Yabuta H, Yurimoto H, Tachibana S, Sawada H, Sakamoto K, Abe M, Arakawa M, Fujii A, Hayakawa M, Hirata N, Hirata N, Honda R, Honda C, Hosoda S, Iijima YI, Ikeda H, Ishiguro M, Ishihara Y, Iwata T, Kawahara K, Kikuchi S, Kitazato K, Matsumoto K, Matsuoka M, Michikami T, Mimasu Y, Miura A, Morota T, Nakazawa S, Namiki N, Noda H, Noguchi R, Ogawa N, Ogawa K, Okada T, Okamoto C, Ono G, Ozaki M, Saiki T, Sakatani N, Senshu H, Shimaki Y, Shirai K, Sugita S, Takei Y, Takeuchi H, Tanaka S, Tatsumi E, Terui F, Tsukizaki R, Wada K, Yamada M, Yamada T, Yamamoto Y, Yano H, Yokota Y, Yoshihara K, Yoshikawa M, Yoshikawa K, Furuya S, Hatakeda K, Hayashi T, Hitomi Y, Kumagai K, Miyazaki A, Nakato A, Nishimura M, Soejima H, Iwamae A, Yamamoto D, Yogata K, Yoshitake M, Fukai R, Usui T, Connolly HC Jr, Lauretta D, Watanabe SI, and Tsuda Y

Abstract

The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth's volatiles. Samples of Ryugu were retrieved by the Hayabusa2 spacecraft. We measured noble gas and nitrogen isotopes in Ryugu samples and found that they are dominated by presolar and primordial components, incorporated during Solar System formation. Noble gas concentrations are higher than those in Ivuna-type carbonaceous (CI) chondrite meteorites. Several host phases of isotopically distinct nitrogen have different abundances among the samples. Our measurements support a close relationship between Ryugu and CI chondrites. Noble gases produced by galactic cosmic rays, indicating a ~5 million year exposure, and from implanted solar wind record the recent irradiation history of Ryugu after it migrated to its current orbit.

Published
2023
Full Text
View/download PDF

44. Macromolecular organic matter in samples of the asteroid (162173) Ryugu.

Author

Yabuta H, Cody GD, Engrand C, Kebukawa Y, De Gregorio B, Bonal L, Remusat L, Stroud R, Quirico E, Nittler L, Hashiguchi M, Komatsu M, Okumura T, Mathurin J, Dartois E, Duprat J, Takahashi Y, Takeichi Y, Kilcoyne D, Yamashita S, Dazzi A, Deniset-Besseau A, Sandford S, Martins Z, Tamenori Y, Ohigashi T, Suga H, Wakabayashi D, Verdier-Paoletti M, Mostefaoui S, Montagnac G, Barosch J, Kamide K, Shigenaka M, Bejach L, Matsumoto M, Enokido Y, Noguchi T, Yurimoto H, Nakamura T, Okazaki R, Naraoka H, Sakamoto K, Connolly HC Jr, Lauretta DS, Abe M, Okada T, Yada T, Nishimura M, Yogata K, Nakato A, Yoshitake M, Iwamae A, Furuya S, Hatakeda K, Miyazaki A, Soejima H, Hitomi Y, Kumagai K, Usui T, Hayashi T, Yamamoto D, Fukai R, Sugita S, Kitazato K, Hirata N, Honda R, Morota T, Tatsumi E, Sakatani N, Namiki N, Matsumoto K, Noguchi R, Wada K, Senshu H, Ogawa K, Yokota Y, Ishihara Y, Shimaki Y, Yamada M, Honda C, Michikami T, Matsuoka M, Hirata N, Arakawa M, Okamoto C, Ishiguro M, Jaumann R, Bibring JP, Grott M, Schröder S, Otto K, Pilorget C, Schmitz N, Biele J, Ho TM, Moussi-Soffys A, Miura A, Noda H, Yamada T, Yoshihara K, Kawahara K, Ikeda H, Yamamoto Y, Shirai K, Kikuchi S, Ogawa N, Takeuchi H, Ono G, Mimasu Y, Yoshikawa K, Takei Y, Fujii A, Iijima YI, Nakazawa S, Hosoda S, Iwata T, Hayakawa M, Sawada H, Yano H, Tsukizaki R, Ozaki M, Terui F, Tanaka S, Fujimoto M, Yoshikawa M, Saiki T, Tachibana S, Watanabe SI, and Tsuda Y

Abstract

Samples of the carbonaceous asteroid (162173) Ryugu were collected and brought to Earth by the Hayabusa2 spacecraft. We investigated the macromolecular organic matter in Ryugu samples and found that it contains aromatic and aliphatic carbon, ketone, and carboxyl functional groups. The spectroscopic features of the organic matter are consistent with those in chemically primitive carbonaceous chondrite meteorites that experienced parent-body aqueous alteration (reactions with liquid water). The morphology of the organic carbon includes nanoglobules and diffuse carbon associated with phyllosilicate and carbonate minerals. Deuterium and/or nitrogen-15 enrichments indicate that the organic matter formed in a cold molecular cloud or the presolar nebula. The diversity of the organic matter indicates variable levels of aqueous alteration on Ryugu's parent body.

Published
2023
Full Text
View/download PDF

45. Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites.

Author

Yokoyama T, Nagashima K, Nakai I, Young ED, Abe Y, Aléon J, Alexander CMO, Amari S, Amelin Y, Bajo KI, Bizzarro M, Bouvier A, Carlson RW, Chaussidon M, Choi BG, Dauphas N, Davis AM, Di Rocco T, Fujiya W, Fukai R, Gautam I, Haba MK, Hibiya Y, Hidaka H, Homma H, Hoppe P, Huss GR, Ichida K, Iizuka T, Ireland TR, Ishikawa A, Ito M, Itoh S, Kawasaki N, Kita NT, Kitajima K, Kleine T, Komatani S, Krot AN, Liu MC, Masuda Y, McKeegan KD, Morita M, Motomura K, Moynier F, Nguyen A, Nittler L, Onose M, Pack A, Park C, Piani L, Qin L, Russell SS, Sakamoto N, Schönbächler M, Tafla L, Tang H, Terada K, Terada Y, Usui T, Wada S, Wadhwa M, Walker RJ, Yamashita K, Yin QZ, Yoneda S, Yui H, Zhang AC, Connolly HC Jr, Lauretta DS, Nakamura T, Naraoka H, Noguchi T, Okazaki R, Sakamoto K, Yabuta H, Abe M, Arakawa M, Fujii A, Hayakawa M, Hirata N, Hirata N, Honda R, Honda C, Hosoda S, Iijima YI, Ikeda H, Ishiguro M, Ishihara Y, Iwata T, Kawahara K, Kikuchi S, Kitazato K, Matsumoto K, Matsuoka M, Michikami T, Mimasu Y, Miura A, Morota T, Nakazawa S, Namiki N, Noda H, Noguchi R, Ogawa N, Ogawa K, Okada T, Okamoto C, Ono G, Ozaki M, Saiki T, Sakatani N, Sawada H, Senshu H, Shimaki Y, Shirai K, Sugita S, Takei Y, Takeuchi H, Tanaka S, Tatsumi E, Terui F, Tsuda Y, Tsukizaki R, Wada K, Watanabe SI, Yamada M, Yamada T, Yamamoto Y, Yano H, Yokota Y, Yoshihara K, Yoshikawa M, Yoshikawa K, Furuya S, Hatakeda K, Hayashi T, Hitomi Y, Kumagai K, Miyazaki A, Nakato A, Nishimura M, Soejima H, Suzuki A, Yada T, Yamamoto D, Yogata K, Yoshitake M, Tachibana S, and Yurimoto H

Abstract

Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples. The samples are mainly composed of materials similar to those of carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37° ± 10°C, about [Formula: see text] million (statistical) or [Formula: see text] million (systematic) years after the formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above ~100°C. The samples have a chemical composition that more closely resembles that of the Sun's photosphere than other natural samples do.

Published
2023
Full Text
View/download PDF

46. A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu.

Author

Noguchi T, Matsumoto T, Miyake A, Igami Y, Haruta M, Saito H, Hata S, Seto Y, Miyahara M, Tomioka N, Ishii HA, Bradley JP, Ohtaki KK, Dobrică E, Leroux H, Le Guillou C, Jacob D, de la Peña F, Laforet S, Marinova M, Langenhorst F, Harries D, Beck P, Phan THV, Rebois R, Abreu NM, Gray J, Zega T, Zanetta PM, Thompson MS, Stroud R, Burgess K, Cymes BA, Bridges JC, Hicks L, Lee MR, Daly L, Bland PA, Zolensky ME, Frank DR, Martinez J, Tsuchiyama A, Yasutake M, Matsuno J, Okumura S, Mitsukawa I, Uesugi K, Uesugi M, Takeuchi A, Sun M, Enju S, Takigawa A, Michikami T, Nakamura T, Matsumoto M, Nakauchi Y, Abe M, Arakawa M, Fujii A, Hayakawa M, Hirata N, Hirata N, Honda R, Honda C, Hosoda S, Iijima YI, Ikeda H, Ishiguro M, Ishihara Y, Iwata T, Kawahara K, Kikuchi S, Kitazato K, Matsumoto K, Matsuoka M, Mimasu Y, Miura A, Morota T, Nakazawa S, Namiki N, Noda H, Noguchi R, Ogawa N, Ogawa K, Okada T, Okamoto C, Ono G, Ozaki M, Saiki T, Sakatani N, Sawada H, Senshu H, Shimaki Y, Shirai K, Sugita S, Takei Y, Takeuchi H, Tanaka S, Tatsumi E, Terui F, Tsukizaki R, Wada K, Yamada M, Yamada T, Yamamoto Y, Yano H, Yokota Y, Yoshihara K, Yoshikawa M, Yoshikawa K, Fukai R, Furuya S, Hatakeda K, Hayashi T, Hitomi Y, Kumagai K, Miyazaki A, Nakato A, Nishimura M, Soejima H, Suzuki AI, Usui T, Yada T, Yamamoto D, Yogata K, Yoshitake M, Connolly HC Jr, Lauretta DS, Yurimoto H, Nagashima K, Kawasaki N, Sakamoto N, Okazaki R, Yabuta H, Naraoka H, Sakamoto K, Tachibana S, Watanabe SI, and Tsuda Y

Abstract

Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe 3+ to Fe 2+ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (-OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2022.)

Published
2023
Full Text
View/download PDF

47. First asteroid gas sample delivered by the Hayabusa2 mission: A treasure box from Ryugu.

Author

Okazaki R, Miura YN, Takano Y, Sawada H, Sakamoto K, Yada T, Yamada K, Kawagucci S, Matsui Y, Hashizume K, Ishida A, Broadley MW, Marty B, Byrne D, Füri E, Meshik A, Pravdivtseva O, Busemann H, Riebe MEI, Gilmour J, Park J, Bajo KI, Righter K, Sakai S, Sekimoto S, Kitajima F, Crowther SA, Iwata N, Shirai N, Ebihara M, Yokochi R, Nishiizumi K, Nagao K, Lee JI, Clay P, Kano A, Caffee MW, Uemura R, Inagaki M, Krietsch D, Maden C, Yamamoto M, Fawcett L, Lawton T, Nakamura T, Naraoka H, Noguchi T, Yabuta H, Yurimoto H, Tsuda Y, Watanabe SI, Abe M, Arakawa M, Fujii A, Hayakawa M, Hirata N, Hirata N, Honda R, Honda C, Hosoda S, Iijima YI, Ikeda H, Ishiguro M, Ishihara Y, Iwata T, Kawahara K, Kikuchi S, Kitazato K, Matsumoto K, Matsuoka M, Michikami T, Mimasu Y, Miura A, Morota T, Nakazawa S, Namiki N, Noda H, Noguchi R, Ogawa N, Ogawa K, Okada T, Okamoto C, Ono G, Ozaki M, Saiki T, Sakatani N, Senshu H, Shimaki Y, Shirai K, Sugita S, Takei Y, Takeuchi H, Tanaka S, Tatsumi E, Terui F, Tsukizaki R, Wada K, Yamada M, Yamada T, Yamamoto Y, Yano H, Yokota Y, Yoshihara K, Yoshikawa M, Yoshikawa K, Furuya S, Hatakeda K, Hayashi T, Hitomi Y, Kumagai K, Miyazaki A, Nakato A, Nishimura M, Soejima H, Iwamae A, Yamamoto D, Yogata K, Yoshitake M, Fukai R, Usui T, Ireland T, Connolly HC Jr, Lauretta DS, and Tachibana S

Abstract

The Hayabusa2 spacecraft returned to Earth from the asteroid 162173 Ryugu on 6 December 2020. One day after the recovery, the gas species retained in the sample container were extracted and measured on-site and stored in gas collection bottles. The container gas consists of helium and neon with an extraterrestrial 3 He/ 4 He and 20 Ne/ 22 Ne ratios, along with some contaminant terrestrial atmospheric gases. A mixture of solar and Earth's atmospheric gas is the best explanation for the container gas composition. Fragmentation of Ryugu grains within the sample container is discussed on the basis of the estimated amount of indigenous He and the size distribution of the recovered Ryugu grains. This is the first successful return of gas species from a near-Earth asteroid.

Published
2022
Full Text
View/download PDF

48. On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective.

Author

Nakamura E, Kobayashi K, Tanaka R, Kunihiro T, Kitagawa H, Potiszil C, Ota T, Sakaguchi C, Yamanaka M, Ratnayake DM, Tripathi H, Kumar R, Avramescu ML, Tsuchida H, Yachi Y, Miura H, Abe M, Fukai R, Furuya S, Hatakeda K, Hayashi T, Hitomi Y, Kumagai K, Miyazaki A, Nakato A, Nishimura M, Okada T, Soejima H, Sugita S, Suzuki A, Usui T, Yada T, Yamamoto D, Yogata K, Yoshitake M, Arakawa M, Fujii A, Hayakawa M, Hirata N, Hirata N, Honda R, Honda C, Hosoda S, Iijima YI, Ikeda H, Ishiguro M, Ishihara Y, Iwata T, Kawahara K, Kikuchi S, Kitazato K, Matsumoto K, Matsuoka M, Michikami T, Mimasu Y, Miura A, Morota T, Nakazawa S, Namiki N, Noda H, Noguchi R, Ogawa N, Ogawa K, Okamoto C, Ono G, Ozaki M, Saiki T, Sakatani N, Sawada H, Senshu H, Shimaki Y, Shirai K, Takei Y, Takeuchi H, Tanaka S, Tatsumi E, Terui F, Tsukizaki R, Wada K, Yamada M, Yamada T, Yamamoto Y, Yano H, Yokota Y, Yoshihara K, Yoshikawa M, Yoshikawa K, Fujimoto M, Watanabe SI, and Tsuda Y

Subjects
Water, Meteoroids, Solar System
Abstract

Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ 18 O, Δ 17 O, and ε 54 Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10's of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation.

Published
2022
Full Text
View/download PDF

49. Spectrally blue hydrated parent body of asteroid (162173) Ryugu.

Author

Tatsumi E, Sakatani N, Riu L, Matsuoka M, Honda R, Morota T, Kameda S, Nakamura T, Zolensky M, Brunetto R, Hiroi T, Sasaki S, Watanabe S, Tanaka S, Takita J, Pilorget C, de León J, Popescu M, Rizos JL, Licandro J, Palomba E, Domingue D, Vilas F, Campins H, Cho Y, Yoshioka K, Sawada H, Yokota Y, Hayakawa M, Yamada M, Kouyama T, Suzuki H, Honda C, Ogawa K, Kitazato K, Hirata N, Hirata N, Tsuda Y, Yoshikawa M, Saiki T, Terui F, Nakazawa S, Takei Y, Takeuchi H, Yamamoto Y, Okada T, Shimaki Y, Shirai K, and Sugita S

Abstract

Ryugu is a carbonaceous rubble-pile asteroid visited by the Hayabusa2 spacecraft. Small rubble pile asteroids record the thermal evolution of their much larger parent bodies. However, recent space weathering and/or solar heating create ambiguities between the uppermost layer observable by remote-sensing and the pristine material from the parent body. Hayabusa2 remote-sensing observations find that on the asteroid (162173) Ryugu both north and south pole regions preserve the material least processed by space weathering, which is spectrally blue carbonaceous chondritic material with a 0-3% deep 0.7-µm band absorption, indicative of Fe-bearing phyllosilicates. Here we report that spectrally blue Ryugu's parent body experienced intensive aqueous alteration and subsequent thermal metamorphism at 570-670 K (300-400 °C), suggesting that Ryugu's parent body was heated by radioactive decay of short-lived radionuclides possibly because of its early formation 2-2.5 Ma. The samples being brought to Earth by Hayabusa2 will give us our first insights into this epoch in solar system history., (© 2021. The Author(s).)

Published
2021
Full Text
View/download PDF

50. Highly porous nature of a primitive asteroid revealed by thermal imaging.

Author

Okada T, Fukuhara T, Tanaka S, Taguchi M, Arai T, Senshu H, Sakatani N, Shimaki Y, Demura H, Ogawa Y, Suko K, Sekiguchi T, Kouyama T, Takita J, Matsunaga T, Imamura T, Wada T, Hasegawa S, Helbert J, Müller TG, Hagermann A, Biele J, Grott M, Hamm M, Delbo M, Hirata N, Hirata N, Yamamoto Y, Sugita S, Namiki N, Kitazato K, Arakawa M, Tachibana S, Ikeda H, Ishiguro M, Wada K, Honda C, Honda R, Ishihara Y, Matsumoto K, Matsuoka M, Michikami T, Miura A, Morota T, Noda H, Noguchi R, Ogawa K, Shirai K, Tatsumi E, Yabuta H, Yokota Y, Yamada M, Abe M, Hayakawa M, Iwata T, Ozaki M, Yano H, Hosoda S, Mori O, Sawada H, Shimada T, Takeuchi H, Tsukizaki R, Fujii A, Hirose C, Kikuchi S, Mimasu Y, Ogawa N, Ono G, Takahashi T, Takei Y, Yamaguchi T, Yoshikawa K, Terui F, Saiki T, Nakazawa S, Yoshikawa M, Watanabe S, and Tsuda Y

Abstract

Carbonaceous (C-type) asteroids 1 are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites 2,3 and are essential for understanding planetary formation processes. However, their physical properties remain poorly known because carbonaceous chondrite meteoroids tend not to survive entry to Earth's atmosphere. Here we report on global one-rotation thermographic images of the C-type asteroid 162173 Ryugu, taken by the thermal infrared imager (TIR) 4 onboard the spacecraft Hayabusa2 5 , indicating that the asteroid's boulders and their surroundings have similar temperatures, with a derived thermal inertia of about 300 J m -2  s -0.5  K -1 (300 tiu). Contrary to predictions that the surface consists of regolith and dense boulders, this low thermal inertia suggests that the boulders are more porous than typical carbonaceous chondrites 6 and that their surroundings are covered with porous fragments more than 10 centimetres in diameter. Close-up thermal images confirm the presence of such porous fragments and the flat diurnal temperature profiles suggest a strong surface roughness effect 7,8 . We also observed in the close-up thermal images boulders that are colder during the day, with thermal inertia exceeding 600 tiu, corresponding to dense boulders similar to typical carbonaceous chondrites 6 . These results constrain the formation history of Ryugu: the asteroid must be a rubble pile formed from impact fragments of a parent body with microporosity 9 of approximately 30 to 50 per cent that experienced a low degree of consolidation. The dense boulders might have originated from the consolidated innermost region or they may have an exogenic origin. This high-porosity asteroid may link cosmic fluffy dust to dense celestial bodies 10 .

Published
2020
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results