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1. The Chemical Composition of Ryugu: Prospects as a Reference Material for Solar System Composition

Author

Yokoyama, Tetsuya, Dauphas, Nicolas, Fukai, Ryota, Usui, Tomohiro, Tachibana, Shogo, Schönbächler, Maria, Busemann, Henner, Abe, Masanao, and Yada, Toru

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

The Hayabusa 2 spacecraft sampled approximately 5.4 g of asteroid material from the Cb-type asteroid Ryugu. Initial analysis of the Ryugu materials revealed a mineralogical, chemical, and isotopic kinship to the CI chondrites. The pristine nature of Ryugu makes the returned samples ideal for constraining the composition of the Solar System. However, some elements (e.g., P, Ca, Mn, and rare earth elements) show large relative dispersions compared to the other elements in the returned materials studied so far, most likely due to the presence of aqueously formed secondary minerals (e.g., carbonates, phosphates) in Ryugu. Therefore, the estimation of the Solar System composition using currently available Ryugu data is challenging due to the so-called nugget effect of carbonates, phosphates, and possibly other accessory minerals. The nugget effect can be mitigated by analyzing a homogenized, relatively large amount of sample. We estimate that for approximately 0.1 g of Ryugu sample, the dispersion (2SD) of the bulk Mn/Cr and Rb/Sr ratios are +/-13% and +/-15%, respectively, while they will be improved to be better than +/-5% for approximately 1 g of homogenized Ryugu sample. To further constrain the Solar System composition and to evaluate if previous estimates based on CI chondrites stored in museums for decades to centuries are reliable, it is strongly recommended to determine the chemical and isotopic compositions of Ryugu using a homogenized sample prepared from relatively large (approx. 1 g) returned material. Determining Ryugu reference compositions will be used by multidisciplinary communities, including Earth and planetary sciences, astronomy, physics, and chemistry., Comment: 13 pages, 5 figures, 2 Tables

Published
2024

2. Microscale Hydrogen, Carbon, and Nitrogen Isotopic Diversity of Organic Matter in Asteroid Ryugu

Author

Nittler, Larry R, Barosch, Jens, Burgess, Katherine, Stroud, Rhonda M, Wang, Jianhua, Yabuta, Hikaru, Enokido, Yuma, Matsumoto, Megumi, Nakamura, Tomoki, Kebukawa, Yoko, Yamashita, Shohei, Takahashi, Yoshio, Bejach, Laure, Bonal, Lydie, Cody, George D, Dartois, Emmanuel, Dazzi, Alexandre, De Gregorio, Bradley, Deniset-Besseau, Ariane, Duprat, Jean, Engrand, Cécile, Hashiguchi, Minako, Kilcoyne, A. L. David, Komatsu, Mutsumi, Martins, Zita, Mathurin, Jérémie, Montagnac, Gilles, Mostefaoui, Smail, Okumura, Taiga, Quirico, Eric, Remusat, Laurent, Sandford, Scott, Shigenaka, Miho, Suga, Hiroki, Takeichi, Yasuo, Tamenori, Yusuke, Verdier-Paoletti, Maximilien, Wakabayashi, Daisuke, Abe, Masanao, Kamide, Kanami, Miyazaki, Akiko, Nakato, Aiko, Nakazawa, Satoru, Nishimura, Masahiro, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Usui, Tomohiro, Yada, Toru, Yogata, Kasumi, Yoshikawa, Makoto, Yurimoto, Hisayoshi, Noguchi, Takaaki, Okazaki, Ryuji, Naraoka, Hiroshi, Sakamoto, Kanako, Tachibana, Shogo, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the H, C, and N isotopic compositions of microscale (0.2 to 2$\mu$m) organic matter in samples of asteroid Ryugu and the Orgueil CI carbonaceous chondrite. Three regolith particles of asteroid Ryugu, returned by the Hayabusa2 spacecraft, and several fragments of Orgueil were analyzed by NanoSIMS isotopic imaging. The isotopic distributions of the Ryugu samples from two different collection spots are closely similar to each other and to the Orgueil samples, strengthening the proposed Ryugu-CI chondrite connection. Most individual sub-$\mu$m organic grains have isotopic compositions within error of bulk values, but 2-8% of them are outliers exhibiting large isotopic enrichments or depletions in D, $^{15}$N, and/or $^{13}$C. The H, C and N isotopic compositions of the outliers are not correlated with each other: while some C-rich grains are both D- and $^{15}$N-enriched, many are enriched or depleted in one or the other system. This most likely points to a diversity in isotopic fractionation pathways and thus diversity in the local formation environments for the individual outlier grains. The observation of a relatively small population of isotopic outlier grains can be explained either by escape from nebular and/or parent body homogenization of carbonaceous precursor material or addition of later isotopic outlier grains. The strong chemical similarity of isotopically typical and isotopically outlying grains, as reflected by synchrotron x-ray absorption spectra, suggests a genetic connection and thus favors the former, homogenization scenario. However, the fact that even the least altered meteorites show the same pattern of a small population of outliers on top of a larger population of homogenized grains indicates that some or most of the homogenization occurred prior to accretion of the macromolecular organic grains into asteroidal parent bodies., Comment: Accepted for publication in Earth and Planetary Science Letters. 8 figures (plus 3 supplementary figs), two tables

Published
2024

4. Water circulation in Ryugu asteroid affected the distribution of nucleosynthetic isotope anomalies in returned sample.

Author

Yokoyama, Tetsuya, Wadhwa, Meenakshi, Iizuka, Tsuyoshi, Rai, Vinai, Gautam, Ikshu, Hibiya, Yuki, Masuda, Yuki, Haba, Makiko, Fukai, Ryota, Hines, Rebekah, Phelan, Nicole, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Ireland, Trevor, Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Koki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Walker, Richard, Yamashita, Katsuyuki, Yoneda, Shigekazu, Young, Edward, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-Ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, and Yin, Qing-Zhu

Abstract

Studies of material returned from Cb asteroid Ryugu have revealed considerable mineralogical and chemical heterogeneity, stemming primarily from brecciation and aqueous alteration. Isotopic anomalies could have also been affected by delivery of exogenous clasts and aqueous mobilization of soluble elements. Here, we show that isotopic anomalies for mildly soluble Cr are highly variable in Ryugu and CI chondrites, whereas those of Ti are relatively uniform. This variation in Cr isotope ratios is most likely due to physicochemical fractionation between 54Cr-rich presolar nanoparticles and Cr-bearing secondary minerals at the millimeter-scale in the bulk samples, likely due to extensive aqueous alteration in their parent bodies that occurred [Formula: see text] after Solar System birth. In contrast, Ti isotopes were marginally affected by this process. Our results show that isotopic heterogeneities in asteroids are not all nebular or accretionary in nature but can also reflect element redistribution by water.

Published
2023

5. Abundant presolar grains and primordial organics preserved in carbon-rich exogenous clasts in asteroid Ryugu.

Author

Nguyen, Ann, Mane, Prajkta, Keller, Lindsay, Piani, Laurette, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor, Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard, Yamashita, Katsuyuki, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-Ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, and Yin, Qing-Zhu

Subjects
Carbon, Solar System, Meteoroids, Silicates
Abstract

Preliminary analyses of asteroid Ryugu samples show kinship to aqueously altered CI (Ivuna-type) chondrites, suggesting similar origins. We report identification of C-rich, particularly primitive clasts in Ryugu samples that contain preserved presolar silicate grains and exceptional abundances of presolar SiC and isotopically anomalous organic matter. The high presolar silicate abundance (104 ppm) indicates that the clast escaped extensive alteration. The 5 to 10 times higher abundances of presolar SiC (~235 ppm), N-rich organic matter, organics with N isotopic anomalies (1.2%), and organics with C isotopic anomalies (0.2%) in the primitive clasts compared to bulk Ryugu suggest that the clasts formed in a unique part of the protoplanetary disk enriched in presolar materials. These clasts likely represent previously unsampled outer solar system material that accreted onto Ryugu after aqueous alteration ceased, consistent with Ryugus rubble pile origin.

Published
2023

6. Breunnerite grain and magnesium isotope chemistry reveal cation partitioning during aqueous alteration of asteroid Ryugu

Author

Yoshimura, Toshihiro, Araoka, Daisuke, Naraoka, Hiroshi, Sakai, Saburo, Ogawa, Nanako O., Yurimoto, Hisayoshi, Morita, Mayu, Onose, Morihiko, Yokoyama, Tetsuya, Bizzarro, Martin, Tanaka, Satoru, Ohkouchi, Naohiko, Koga, Toshiki, Dworkin, Jason P., Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Watanabe, Sei-ichiro, Tsuda, Yuichi, Tachibana, Shogo, and Takano, Yoshinori

Published
2024
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7. Variations of organic functional chemistry in carbonaceous matter from the asteroid 162173 Ryugu

Author

De Gregorio, Bradley, Cody, George D., Stroud, Rhonda M., David Kilcoyne, A. L., Sandford, Scott, Le Guillou, Corentin, Nittler, Larry R., Barosch, Jens, Yabuta, Hikaru, Martins, Zita, Kebukawa, Yoko, Okumura, Taiga, Hashiguchi, Minako, Yamashita, Shohei, Takeichi, Yasuo, Takahashi, Yoshio, Wakabayashi, Daisuke, Engrand, Cécile, Bejach, Laure, Bonal, Lydie, Quirico, Eric, Remusat, Laurent, Duprat, Jean, Verdier-Paoletti, Maximilien, Mostefaoui, Smail, Komatsu, Mutsumi, Mathurin, Jérémie, Dazzi, Alexandre, Deniset-Besseau, Ariane, Dartois, Emmanuel, Tamenori, Yusuke, Suga, Hiroki, Montagnac, Gilles, Kamide, Kanami, Shigenaka, Miho, Matsumoto, Megumi, Enokido, Yuma, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Usui, Tomohiro, Abe, Masanao, Okada, Tatsuaki, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Yurimoto, Hisayoshi, Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Naraoka, Hiroshi, Sakamoto, Kanako, Tachibana, Shogo, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2024
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8. Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu

Author

Takano, Yoshinori, Naraoka, Hiroshi, Dworkin, Jason P., Koga, Toshiki, Sasaki, Kazunori, Sato, Hajime, Oba, Yasuhiro, Ogawa, Nanako O., Yoshimura, Toshihiro, Hamase, Kenji, Ohkouchi, Naohiko, Parker, Eric T., Aponte, José C., Glavin, Daniel P., Furukawa, Yoshihiro, Aoki, Junken, Kano, Kuniyuki, Nomura, Shin-ichiro M., Orthous-Daunay, Francois-Regis, Schmitt-Kopplin, Philippe, Yurimoto, Hisayoshi, Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Watanabe, Sei-ichiro, Tsuda, Yuichi, and Tachibana, Shogo

Published
2024
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9. Nonmagnetic framboid and associated iron nanoparticles with a space-weathered feature from asteroid Ryugu

Author

Kimura, Yuki, Kato, Takeharu, Anada, Satoshi, Yoshida, Ryuji, Yamamoto, Kazuo, Tanigaki, Toshiaki, Akashi, Tetsuya, Kasai, Hiroto, Kurosawa, Kosuke, Nakamura, Tomoki, Noguchi, Takaaki, Sato, Masahiko, Matsumoto, Toru, Morita, Tomoyo, Kikuiri, Mizuha, Amano, Kana, Kagawa, Eiichi, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Yurimoto, Hisayoshi, Okazaki, Ryuji, Yabuta, Hikaru, Naraoka, Hiroshi, Sakamoto, Kanako, Watanabe, Sei-ichiro, Tsuda, Yuichi, and Tachibana, Shogo

Published
2024
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11. Influx of nitrogen-rich material from the outer Solar System indicated by iron nitride in Ryugu samples

Author

Matsumoto, Toru, Noguchi, Takaaki, Miyake, Akira, Igami, Yohei, Haruta, Mitsutaka, Seto, Yusuke, Miyahara, Masaaki, Tomioka, Naotaka, Saito, Hikaru, Hata, Satoshi, Harries, Dennis, Takigawa, Aki, Nakauchi, Yusuke, Tachibana, Shogo, Nakamura, Tomoki, Matsumoto, Megumi, Ishii, Hope A., Bradley, John P., Ohtaki, Kenta, Dobrică, Elena, Leroux, Hugues, Le Guillou, Corentin, Jacob, Damien, de la Peña, Francisco, Laforet, Sylvain, Marinova, Maya, Langenhorst, Falko, Beck, Pierre, Phan, Thi H. V., Rebois, Rolando, Abreu, Neyda M., Gray, Jennifer, Zega, Thomas, Zanetta, Pierre-M., Thompson, Michelle S., Stroud, Rhonda, Burgess, Kate, Cymes, Brittany A., Bridges, John C., Hicks, Leon, Lee, Martin R., Daly, Luke, Bland, Phil A., Zolensky, Michael E., Frank, David R., Martinez, James, Tsuchiyama, Akira, Yasutake, Masahiro, Matsuno, Junya, Okumura, Shota, Mitsukawa, Itaru, Uesugi, Kentaro, Uesugi, Masayuki, Takeuchi, Akihisa, Sun, Mingqi, Enju, Satomi, Michikami, Tatsuhiro, Yurimoto, Hisayoshi, Okazaki, Ryuji, Yabuta, Hikaru, Naraoka, Hiroshi, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2024
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12. Presolar stardust in asteroid Ryugu

Author

Barosch, Jens, Nittler, Larry R., Wang, Jianhua, Alexander, Conel M. O'D., De Gregorio, Bradley T., Engrand, Cécile, Kebukawa, Yoko, Nagashima, Kazuhide, Stroud, Rhonda M., Yabuta, Hikaru, Abe, Yoshinari, Aléon, Jérôme, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bejach, Laure, Bizzarro, Martin, Bonal, Lydie, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Cody, George D., Dartois, Emmanuel, Dauphas, Nicolas, Davis, Andrew M., Dazzi, Alexandre, Deniset-Besseau, Ariane, Di Rocco, Tommaso, Duprat, Jean, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hashiguchi, Minako, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kamide, Kanami, Kawasaki, Noriyuki, Kilcoyne, A. L. David, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Komatsu, Mutsumi, Krot, Alexander N., Liu, Ming-Chang, Martins, Zita, Masuda, Yuki, Mathurin, Jérémie, McKeegan, Kevin D., Montagnac, Gilles, Morita, Mayu, Mostefaoui, Smail, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nguyen, Ann N., Ohigashi, Takuji, Okumura, Taiga, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Quirico, Eric, Remusat, Laurent, Russell, Sara S., Sakamoto, Naoya, Sandford, Scott A., Schönbächler, Maria, Shigenaka, Miho, Suga, Hiroki, Tafla, Lauren, Takahashi, Yoshio, Takeichi, Yasuo, Tamenori, Yusuke, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Verdier-Paoletti, Maximilien, Wada, Sohei, Wadhwa, Meenakshi, Wakabayashi, Daisuke, Walker, Richard J., Yamashita, Katsuyuki, Yamashita, Shohei, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nakazawa, Satoru, Nishimura, Masahiro, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yada, Toru, Yogata, Kasumi, Yoshikawa, Makoto, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Tachibana, Shogo, and Yurimoto, Hisayoshi

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

We have conducted a NanoSIMS-based search for presolar material in samples recently returned from C-type asteroid Ryugu as part of JAXA's Hayabusa2 mission. We report the detection of all major presolar grain types with O- and C-anomalous isotopic compositions typically identified in carbonaceous chondrite meteorites: 1 silicate, 1 oxide, 1 O-anomalous supernova grain of ambiguous phase, 38 SiC, and 16 carbonaceous grains. At least two of the carbonaceous grains are presolar graphites, whereas several grains with moderate C isotopic anomalies are probably organics. The presolar silicate was located in a clast with a less altered lithology than the typical extensively aqueously altered Ryugu matrix. The matrix-normalized presolar grain abundances in Ryugu are 4.8$^{+4.7}_{-2.6}$ ppm for O-anomalous grains, 25$^{+6}_{-5}$ ppm for SiC grains and 11$^{+5}_{-3}$ ppm for carbonaceous grains. Ryugu is isotopically and petrologically similar to carbonaceous Ivuna-type (CI) chondrites. To compare the in situ presolar grain abundances of Ryugu with CI chondrites, we also mapped Ivuna and Orgueil samples and found a total of SiC grains and 6 carbonaceous grains. No O-anomalous grains were detected. The matrix-normalized presolar grain abundances in the CI chondrites are similar to those in Ryugu: 23 $^{+7}_{-6}$ ppm SiC and 9.0$^{+5.3}_{-4.6}$ ppm carbonaceous grains. Thus, our results provide further evidence in support of the Ryugu-CI connection. They also reveal intriguing hints of small-scale heterogeneities in the Ryugu samples, such as locally distinct degrees of alteration that allowed the preservation of delicate presolar material., Comment: 12 pages, 3 figures, 2 tables. Published in ApJL

Published
2022
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13. In-situ wavelength calibration without a calibration target: use of Fraunhofer lines after landing on planetary surface

Author

Mori, Shoki, Boettger, Ute, Buder, Maximilian, Cho, Yuichiro, Dietz, Enrico, Hagelschuer, Till, Hübers, Heinz-Wilhelm, Kameda, Shingo, Kopp, Emanuel, Prieto-Ballesteros, Olga, Rull, Fernando, Ryan, Conor, Schroeder, Susanne, Sugita, Seiji, Tabata, Haruhisa, Usui, Tomohiro, and Yumoto, Koki

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

Accurate wavelength calibration is critical for qualitative and quantitative spectroscopic measurements. Many spectrometers for planetary exploration are equipped with onboard calibration sources. However, such calibration sources are not always available because planetary lander missions often have strong limitations in size and mass. In this study, we propose and validate a wavelength calibration method using solar Fraunhofer lines observed in reflective spectra. As a result, for a visible Raman spectrometer, the accuracy is better than 0.6 cm-1 in 0-4000 cm-1 range, and the magnesium abundance of olivine is estimated more accurately than 2%.

Published
2022

14. Oxygen isotopes of anhydrous primary minerals show kinship between asteroid Ryugu and comet 81P/Wild2

Author

Kawasaki, Noriyuki, Nagashima, Kazuhide, Sakamoto, Naoya, Matsumoto, Toru, Bajo, Ken-ichi, Wada, Sohei, Igami, Yohei, Miyake, Akira, Noguchi, Takaaki, Yamamoto, Daiki, Russell, Sara S, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M O’D, Amari, Sachiko, Amelin, Yuri, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M, Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R, Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R, Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kita, Noriko T, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wadhwa, Meenakshi, Walker, Richard J, Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Subjects
Earth Sciences, Physical Sciences, Space Sciences, Geology, Prevention
Abstract

The extraterrestrial materials returned from asteroid (162173) Ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to CI (Ivuna-type) carbonaceous chondrites. Here, we show that high-temperature anhydrous primary minerals in Ryugu and CI chondrites exhibit a bimodal distribution of oxygen isotopic compositions: 16O-rich (associated with refractory inclusions) and 16O-poor (associated with chondrules). Both the 16O-rich and 16O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward. The abundance ratios of the 16O-rich to 16O-poor minerals in Ryugu and CI chondrites are higher than in other carbonaceous chondrite groups but are similar to that of comet 81P/Wild2, suggesting that Ryugu and CI chondrites accreted in the outer Solar System closer to the accretion region of comets.

Published
2022

15. Pyrrhotites in asteroid 162173 Ryugu: Records of the initial changes on their surfaces with aqueous alteration

Author

Yui, Hiroharu, Urashima, Shu-hei, Onose, Morihiko, Morita, Mayu, Komatani, Shintaro, Nakai, Izumi, Abe, Yoshinari, Terada, Yasuko, Homma, Hisashi, Motomura, Kazuko, Ichida, Kiyohiro, Yokoyama, Tetsuya, Nagashima, Kazuhide, Aléon, Jérôme, M. O’D. Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Hoppe, Peter, Huss, Gary R., Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Krot, Sasha, Liu, Ming-Chang, Masuda, Yuki, Moynier, Frédéric, Nguyen, Ann, Nittler, Larry, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Di Rocco, Tommaso, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Published
2024
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16. Development of a multispectral stereo-camera system comparable to Hayabusa2 Optical Navigation Camera (ONC-T) for observing samples returned from asteroid (162173) Ryugu

Author

Cho, Yuichiro, Yumoto, Koki, Yabe, Yuna, Mori, Shoki, Ogura, Jo A., Yada, Toru, Miyazaki, Akiko, Yogata, Kasumi, Hatakeda, Kentaro, Nishimura, Masahiro, Abe, Masanao, Usui, Tomohiro, and Sugita, Seiji

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

Hayabusa2 collected 5.4 g of samples from the asteroid (162173) Ryugu and brought them back to Earth. Obtaining multiband images of these samples with the spectral bands comparable to those used for remote-sensing observations is important for characterizing the collected samples and examining how representative the sample is compared with spacecraft observations of Ryugu as a whole. In this study, we constructed a multiband microscopic camera system that enables both visual multispectral imaging at 390 (ul), 475 (b), 550 (v), 590 (Na), 700 (w), and 850 nm (x), and three-dimensional (3D) shape reconstruction of individual grain samples based on stereo imaging. The imaging system yields the images of 4096 x 2160 pixels with the pixel resolution of 1.93 {\mu}m/pix and field of view of 7.9 x 4.2 mm. Our validation measurements demonstrate that our multispectral imaging system, which observes the samples with the spectral bands comparable to those on the telescopic optical navigation camera (ONC-T) on Hayabusa2, yields reflectance spectra with a relative error of 3% and a 3D model with an error of 5%. These results indicate that the multiband imaging system with a 3D shape reconstruction capability yields accurate spectral and shape data on the returned samples. Using this instrument, we conducted multispectral measurements of two Ryugu samples (grains in the dishes A3 and C1) acquired from two locations on the asteroid. The average spectra of the measured Ryugu samples were flat and consistent with the global averaged spectrum of Ryugu. The 550-nm band (v-band) reflectance of the returned grains in the dishes was 2.4% on average, higher than that of the global averaged spectrum of Ryugu observed with ONC-T. This apparent difference could be because the returned grains have greater specular reflectance.

Published
2021
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17. Revised phase diagram of the high-$T_c$ cuprate superconductor Pb-doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ revealed by anisotropic transport measurements

Author

Harada, Keiichi, Teramoto, Yuki, Usui, Tomohiro, Itaka, Kenji, Fujii, Takenori, Noji, Takashi, Taniguchi, Haruka, Matsukawa, Michiaki, Ishikawa, Hajime, Kindo, Koichi, Dessau, Daniel S., and Watanabe, Takao

Subjects
Condensed Matter - Superconductivity
Abstract

Although phase diagrams can be leveraged to investigate high transition temperature (high-$T_c$) superconductivity, the issue has not been discussed thoroughly. In this study, we elucidate the phase diagram of the overdoped side of high-$T_c$ cuprates via systematic anisotropic transport measurements for Pb-doped Bi-2212 single crystals. We demonstrate that the characteristic temperatures of the "weak" pseudogap opening and electronic coherence cross each other at a critical doping level, while those of the "strong" pseudogap merges into that of superconducting fluctuations above the critical doping level. Our results indicate the importance of Mottness in high-$T_c$ superconductivity., Comment: 8 pages, 9 figures; The title is changed

Published
2021
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18. Three-dimensional textures of Ryugu samples and their implications for the evolution of aqueous alteration in the Ryugu parent body

Author

Tsuchiyama, Akira, Matsumoto, Megumi, Matsuno, Junya, Yasutake, Masahiro, Nakamura, Tomoki, Noguchi, Takaaki, Miyake, Akira, Uesugi, Kentaro, Takeuchi, Akihisa, Okumura, Shota, Fujioka, Yuri, Sun, Mingqi, Takigawa, Aki, Matsumoto, Toru, Enju, Satomi, Mitsukawa, Itaru, Enokido, Yuma, Kawamoto, Tatsuhiko, Mikouchi, Takeshi, Michikami, Tatsuhiro, Morita, Tomoyo, Kikuiri, Mizuha, Amano, Kana, Kagawa, Eiichi, Rubino, Stefano, Dionnet, Zelia, Aléon-Toppani, Alice, Brunetto, Rosario, Zolensky, Michael E., Nakano, Tsukasa, Nakano, Naoto, Yurimoto, Hisayoshi, Okazaki, Ryuji, Yabuta, Hikaru, Naraoka, Hiroshi, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Nakazawa, Satoru, Terui, Fuyuto, Tachibana, Shogo, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2024
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19. Enantioselective three-dimensional high-performance liquid chromatographic determination of amino acids in the Hayabusa2 returned samples from the asteroid Ryugu

Author

Furusho, Aogu, Ishii, Chiharu, Akita, Takeyuki, Oyaide, Mai, Mita, Masashi, Naraoka, Hiroshi, Takano, Yoshinori, Dworkin, Jason P., Oba, Yasuhiro, Koga, Toshiki, Fukushima, Kazuhiko, Aoki, Dan, Hashiguchi, Minako, Mita, Hajime, Chikaraishi, Yoshito, Ohkouchi, Naohiko, Ogawa, Nanako O., Sakai, Saburo, Glavin, Daniel P., Elsila, Jamie E., Parker, Eric T., Aponte, José C., McLain, Hannah L., Orthous-Daunay, Francois-Regis, Vuitton, Véronique, Thissen, Roland, Wolters, Cédric, Schmitt-Kopplin, Philippe, Ruf, Alexander, Isa, Junko, Hertkorn, Norbert, Eiler, John M., Yoshimura, Toshihiro, Sugahara, Haruna, Graham, Heather V., Furukawa, Yoshihiro, Araoka, Daisuke, Tanaka, Satoru, Yoshikawa, Takaaki, Kabashima, Fumie, Sasaki, Kazunori, Sato, Hajime, Yamazaki, Tomoya, Onose, Morihiko, Morita, Mayu, Kimura, Yuki, Kano, Kuniyuki, Aoki, Junken, Fujishima, Kosuke, Nomura, Shin-ichiro, Tachibana, Shogo, Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Yurimoto, Hisayoshi, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Okada, Tatsuaki, Watanabe, Sei-ichiro, Tsuda, Yuichi, and Hamase, Kenji

Published
2024
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20. A newly revised estimation of bulk densities and examination of the shape of individual Ryugu grains

Author

Miyazaki, Akiko, Yada, Toru, Yogata, Kasumi, Hatakeda, Kentaro, Nakato, Aiko, Nishimura, Masahiro, Nagashima, Kana, Kumagai, Kazuya, Hitomi, Yuya, Soejima, Hiromichi, Tahara, Rui, Kanemaru, Rei, Nakano, Arisa, Yoshitake, Miwa, Iwamae, Ayako, Furuya, Shizuho, Tsuchiyama, Akira, Tachibana, Shogo, Michikami, Tatsuhiro, Okada, Tatsuaki, Abe, Masanao, and Usui, Tomohiro

Published
2023
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21. A curation for uncontaminated Hayabusa2-returned samples in the extraterrestrial curation center of JAXA: from the beginning to present day

Author

Yada, Toru, Abe, Masanao, Nishimura, Masahiro, Sawada, Hirotaka, Okazaki, Ryuji, Takano, Yoshinori, Sakamoto, Kanako, Okada, Tatsuaki, Nakato, Aiko, Yoshitake, Miwa, Nakano, Yuki, Yogata, Kasumi, Miyazaki, Akiko, Furuya, Shizuho, Iwamae, Ayako S., Nakatsubo, Shunichi, Hatakeda, Kentaro, Hitomi, Yuya, Kumagai, Kazuya, Suzuki, Shino, Miura, Yayoi N., Ito, Motoo, Tomioka, Naotaka, Uesugi, Masayuki, Karouji, Yuzuru, Uesugi, Kentaro, Shirai, Naoki, Yamaguchi, Akira, Imae, Naoya, Naraoka, Hiroshi, Yamamoto, Yuhji, Tachibana, Shogo, Yurimoto, Hisayoshi, and Usui, Tomohiro

Published
2023
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22. Soluble organic matter Molecular atlas of Ryugu reveals cold hydrothermalism on C-type asteroid parent body

Author

Schmitt-Kopplin, Philippe, Hertkorn, Norbert, Harir, Mourad, Moritz, Franco, Lucio, Marianna, Bonal, Lydie, Quirico, Eric, Takano, Yoshinori, Dworkin, Jason P., Naraoka, Hiroshi, Tachibana, Shogo, Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Yurimoto, Hisayoshi, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Okada, Tatsuaki, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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23. Space weathering acts strongly on the uppermost surface of Ryugu

Author

Matsuoka, Moe, Kagawa, Ei-ichi, Amano, Kana, Nakamura, Tomoki, Tatsumi, Eri, Osawa, Takahito, Hiroi, Takahiro, Milliken, Ralph, Domingue, Deborah, Takir, Driss, Brunetto, Rosario, Barucci, Antonella, Kitazato, Kohei, Sugita, Seiji, Fujioka, Yuri, Sasaki, Osamu, Kobayashi, Shiho, Iwata, Takahiro, Morota, Tomokatsu, Yokota, Yasuhiro, Kouyama, Toru, Honda, Rie, Kameda, Shingo, Cho, Yuichiro, Yoshioka, Kazuo, Sawada, Hirotaka, Hayakawa, Masahiko, Sakatani, Naoya, Yamada, Manabu, Suzuki, Hidehiko, Honda, Chikatoshi, Ogawa, Kazunori, Shirai, Kei, Lantz, Cateline, Rubino, Stefano, Yurimoto, Hisayoshi, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Naraoka, Hiroshi, Sakamoto, Kanako, Tachibana, Shogo, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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24. Chemical evolution of primordial salts and organic sulfur molecules in the asteroid 162173 Ryugu

Author

Yoshimura, Toshihiro, Takano, Yoshinori, Naraoka, Hiroshi, Koga, Toshiki, Araoka, Daisuke, Ogawa, Nanako O., Schmitt-Kopplin, Philippe, Hertkorn, Norbert, Oba, Yasuhiro, Dworkin, Jason P., Aponte, José C., Yoshikawa, Takaaki, Tanaka, Satoru, Ohkouchi, Naohiko, Hashiguchi, Minako, McLain, Hannah, Parker, Eric T., Sakai, Saburo, Yamaguchi, Mihoko, Suzuki, Takahiro, Yokoyama, Tetsuya, Yurimoto, Hisayoshi, Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Watanabe, Sei-ichiro, Tsuda, Yuichi, and Tachibana, Shogo

Published
2023
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25. Ryugu Sample Database System (RS-DBS) on the Data Archives and Transmission System (DARTS) by the JAXA curation

Author

Nishimura, Masahiro, Nakato, Aiko, Abe, Masanao, Nagashima, Kana, Soejima, Hiromichi, Yada, Toru, Yogata, Kasumi, Miyazaki, Akiko, Hatakeda, Kentaro, Yoshitake, Miwa, Iwamae, Ayako, Pilorget, Cedric, Brunetto, Rosario, Loizeau, Damien, Bibring, Jean-Pierre, Riu, Lucie, Yumoto, Koki, Cho, Yuichiro, Yabe, Yuna, Sugita, Seiji, Ito, Motoo, Okada, Tatsuaki, Tachibana, Shogo, and Usui, Tomohiro

Published
2023
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26. Visualization of nanoscale magnetic domain states in the asteroid Ryugu

Author

Kimura, Yuki, Kato, Takeharu, Tanigaki, Toshiaki, Akashi, Tetsuya, Kasai, Hiroto, Anada, Satoshi, Yoshida, Ryuji, Yamamoto, Kazuo, Nakamura, Tomoki, Sato, Masahiko, Amano, Kana, Kikuiri, Mizuha, Morita, Tomoyo, Kagawa, Eiichi, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Yurimoto, Hisayoshi, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Naraoka, Hiroshi, Sakamoto, Kanako, Watanabe, Sei-ichiro, Tsuda, Yuichi, and Tachibana, Shogo

Published
2023
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27. Insights into the formation and evolution of extraterrestrial amino acids from the asteroid Ryugu

Author

Potiszil, Christian, Ota, Tsutomu, Yamanaka, Masahiro, Sakaguchi, Chie, Kobayashi, Katsura, Tanaka, Ryoji, Kunihiro, Tak, Kitagawa, Hiroshi, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nakazawa, Satoru, Nishimura, Masahiro, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Usui, Tomohiro, Watanabe, Sei-ichiro, Yada, Toru, Yogata, Kasumi, Yoshikawa, Makoto, and Nakamura, Eizo

Published
2023
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28. Uracil in the carbonaceous asteroid (162173) Ryugu

Author

Oba, Yasuhiro, Koga, Toshiki, Takano, Yoshinori, Ogawa, Nanako O., Ohkouchi, Naohiko, Sasaki, Kazunori, Sato, Hajime, Glavin, Daniel P., Dworkin, Jason P., Naraoka, Hiroshi, Tachibana, Shogo, Yurimoto, Hisayoshi, Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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29. PAHs, hydrocarbons, and dimethylsulfides in Asteroid Ryugu samples A0106 and C0107 and the Orgueil (CI1) meteorite

Author

Aponte, José C., Dworkin, Jason P., Glavin, Daniel P., Elsila, Jamie E., Parker, Eric T., McLain, Hannah L., Naraoka, Hiroshi, Okazaki, Ryuji, Takano, Yoshinori, Tachibana, Shogo, Dong, Guannan, Zeichner, Sarah S., Eiler, John M., Yurimoto, Hisayoshi, Nakamura, Tomoki, Yabuta, Hikaru, Terui, Fuyuto, Noguchi, Takaaki, Sakamoto, Kanako, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Nakazawa, Satoru, Tsuda, Yuichi, and Watanabe, Sei-ichiro

Published
2023
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30. Chondrule-like objects and Ca-Al-rich inclusions in Ryugu may potentially be the oldest Solar System materials

Author

Nakashima, Daisuke, Nakamura, Tomoki, Zhang, Mingming, Kita, Noriko T., Mikouchi, Takashi, Yoshida, Hideto, Enokido, Yuma, Morita, Tomoyo, Kikuiri, Mizuha, Amano, Kana, Kagawa, Eiichi, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Nakazawa, Satoru, Terui, Fuyuto, Yurimoto, Hisayoshi, Noguchi, Takaaki, Yabuta, Hikaru, Naraoka, Hiroshi, Okazaki, Ryuji, Sakamoto, Kanako, Watanabe, Sei-ichiro, Tachibana, Shogo, and Tsuda, Yuichi

Published
2023
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31. The spatial distribution of soluble organic matter and their relationship to minerals in the asteroid (162173) Ryugu

Author

Hashiguchi, Minako, Aoki, Dan, Fukushima, Kazuhiko, Naraoka, Hiroshi, Takano, Yoshinori, Dworkin, Jason P., Dworkin, Karin E., Aponte, José C., Elsila, Jamie E., Eiler, John M., Furukawa, Yoshihiro, Furusho, Aogu, Glavin, Daniel P., Graham, Heather V., Hamase, Kenji, Hertkorn, Norbert, Isa, Junko, Koga, Toshiki, McLain, Hannah L., Mita, Hajime, Oba, Yasuhiro, Ogawa, Nanako O., Ohkouchi, Naohiko, Orthous-Daunay, Francois-Regis, Parker, Eric T., Ruf, Alexander, Sakai, Saburo, Schmitt-Kopplin, Philippe, Sugahara, Haruna, Thissen, Roland, Vuitton, Véronique, Wolters, Cédric, Yoshimura, Toshihiro, Yurimoto, Hisayoshi, Nakamura, Tomoki, Noguchi, Takaaki, Okazaki, Ryuji, Yabuta, Hikaru, Sakamoto, Kanako, Tachibana, Shogo, Yada, Toru, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Yogata, Kasumi, Abe, Masanao, Usui, Tomohiro, Yoshikawa, Makoto, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Nakazawa, Satoru, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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32. Variations of the surface characteristics of Ryugu returned samples

Author

Nakato, Aiko, Yada, Toru, Nishimura, Masahiro, Yogata, Kasumi, Miyazaki, Akiko, Nagashima, Kana, Hatakeda, Kentaro, Kumagai, Kazuya, Hitomi, Yuya, Soejima, Hiromichi, Bibring, Jean-Pierre, Pilorget, Cedric, Hamm, Vincent, Brunetto, Rosario, Riu, Lucie, Lourit, Lionel, Loizeau, Damien, Le Pivert-Jolivet, Tania, Lequertier, Guillaume, Moussi-Soffys, Aurelie, Abe, Masanao, Okada, Tatsuaki, Usui, Tomohiro, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Yoshikawa, Makoto, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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34. A history of mild shocks experienced by the regolith particles on hydrated asteroid Ryugu

Author

Tomioka, Naotaka, Yamaguchi, Akira, Ito, Motoo, Uesugi, Masayuki, Imae, Naoya, Shirai, Naoki, Ohigashi, Takuji, Kimura, Makoto, Liu, Ming-Chang, Greenwood, Richard C., Uesugi, Kentaro, Nakato, Aiko, Yogata, Kasumi, Yuzawa, Hayato, Kodama, Yu, Hirahara, Kaori, Sakurai, Ikuya, Okada, Ikuo, Karouji, Yuzuru, Okazaki, Keishi, Kurosawa, Kosuke, Noguchi, Takaaki, Miyake, Akira, Miyahara, Masaaki, Seto, Yusuke, Matsumoto, Toru, Igami, Yohei, Nakazawa, Satoru, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Yoshikawa, Makoto, Miyazaki, Akiko, Nishimura, Masahiro, Yada, Toru, Abe, Masanao, Usui, Tomohiro, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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35. Insight into multi-step geological evolution of C-type asteroids from Ryugu particles

Author

Yamaguchi, Akira, Tomioka, Naotaka, Ito, Motoo, Shirai, Naoki, Kimura, Makoto, Greenwood, Richard C., Liu, Ming-Chang, McCain, Kaitlyn A., Matsuda, Nozomi, Uesugi, Masayuki, Imae, Naoya, Ohigashi, Takuji, Uesugi, Kentaro, Nakato, Aiko, Yogata, Kasumi, Yuzawa, Hayato, Kodama, Yu, Hirahara, Kaori, Sakurai, Ikuya, Okada, Ikuo, Karouji, Yuzuru, Nakazawa, Satoru, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Yoshikawa, Makoto, Miyazaki, Akiko, Nishimura, Masahiro, Yada, Toru, Abe, Masanao, Usui, Tomohiro, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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37. Pervasive aqueous alteration in the early Solar System revealed by potassium isotopic variations in Ryugu samples and carbonaceous chondrites

Author

Hu, Yan, Moynier, Frédéric, Dai, Wei, Paquet, Marine, Yokoyama, Tetsuya, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Koki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Published
2024
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38. The thermal history of Ryugu based on Raman characterization of Hayabusa2 samples

Author

Bonal, Lydie, Quirico, Eric, Montagnac, Gilles, Komatsu, Mutsumi, Kebukawa, Yoko, Yabuta, Hikaru, Amano, Kana, Barosch, Jens, Bejach, Laure, Cody, George D., Dartois, Emmanuel, Dazzi, Alexandre, De Gregorio, Bradley, Deniset-Besseau, Ariane, Duprat, Jean, Engrand, Cécile, Hashiguchi, Minako, Kamide, Kanami, Kilcoyne, David, Martins, Zita, Mathurin, Jérémie, Mostefaoui, Smail, Nittler, Larry, Ohigashi, Takuji, Okumura, Taiga, Remusat, Laurent, Sandford, Scott, Shigenaka, Miho, Stroud, Rhonda, Suga, Hiroki, Takahashi, Yoshio, Takeichi, Yasuo, Tamenori, Yusuke, Verdier-Paoletti, Maximilien, Yamashita, Shohei, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Yurimoto, Hisayoshi, Tachibana, Shogo, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nakazawa, Satoru, Nishimura, Masahiro, Okada, Tatsuaki, Saiki, Takanao, Sakamoto, Kanako, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Usui, Tomohiro, Watanabe, Sei-ichiro, Yada, Toru, Yogata, Kasumi, and Yoshikawa, Makota

Published
2024
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40. Early fluid activity on Ryugu inferred by isotopic analyses of carbonates and magnetite

Author

McCain, Kaitlyn A., Matsuda, Nozomi, Liu, Ming-Chang, McKeegan, Kevin D., Yamaguchi, Akira, Kimura, Makoto, Tomioka, Naotaka, Ito, Motoo, Imae, Naoya, Uesugi, Masayuki, Shirai, Naoki, Ohigashi, Takuji, Greenwood, Richard C., Uesugi, Kentaro, Nakato, Aiko, Yogata, Kasumi, Yuzawa, Hayato, Kodama, Yu, Hirahara, Kaori, Sakurai, Ikuya, Okada, Ikuo, Karouji, Yuzuru, Nakazawa, Satoru, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Yoshikawa, Makoto, Miyazaki, Akiko, Nishimura, Masahiro, Yada, Toru, Abe, Masanao, Usui, Tomohiro, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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41. A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu

Author

Noguchi, Takaaki, Matsumoto, Toru, Miyake, Akira, Igami, Yohei, Haruta, Mitsutaka, Saito, Hikaru, Hata, Satoshi, Seto, Yusuke, Miyahara, Masaaki, Tomioka, Naotaka, Ishii, Hope A., Bradley, John P., Ohtaki, Kenta K., Dobrică, Elena, Leroux, Hugues, Le Guillou, Corentin, Jacob, Damien, de la Peña, Francisco, Laforet, Sylvain, Marinova, Maya, Langenhorst, Falko, Harries, Dennis, Beck, Pierre, Phan, Thi H. V., Rebois, Rolando, Abreu, Neyda M., Gray, Jennifer, Zega, Thomas, Zanetta, Pierre-M., Thompson, Michelle S., Stroud, Rhonda, Burgess, Kate, Cymes, Brittany A., Bridges, John C., Hicks, Leon, Lee, Martin R., Daly, Luke, Bland, Phil A., Zolensky, Michael E., Frank, David R., Martinez, James, Tsuchiyama, Akira, Yasutake, Masahiro, Matsuno, Junya, Okumura, Shota, Mitsukawa, Itaru, Uesugi, Kentaro, Uesugi, Masayuki, Takeuchi, Akihisa, Sun, Mingqi, Enju, Satomi, Takigawa, Aki, Michikami, Tatsuhiro, Nakamura, Tomoki, Matsumoto, Megumi, Nakauchi, Yusuke, Abe, Masanao, Arakawa, Masahiko, Fujii, Atsushi, Hayakawa, Masahiko, Hirata, Naru, Hirata, Naoyuki, Honda, Rie, Honda, Chikatoshi, Hosoda, Satoshi, Iijima, Yu-ichi, Ikeda, Hitoshi, Ishiguro, Masateru, Ishihara, Yoshiaki, Iwata, Takahiro, Kawahara, Kousuke, Kikuchi, Shota, Kitazato, Kohei, Matsumoto, Koji, Matsuoka, Moe, Mimasu, Yuya, Miura, Akira, Morota, Tomokatsu, Nakazawa, Satoru, Namiki, Noriyuki, Noda, Hirotomo, Noguchi, Rina, Ogawa, Naoko, Ogawa, Kazunori, Okada, Tatsuaki, Okamoto, Chisato, Ono, Go, Ozaki, Masanobu, Saiki, Takanao, Sakatani, Naoya, Sawada, Hirotaka, Senshu, Hiroki, Shimaki, Yuri, Shirai, Kei, Sugita, Seiji, Takei, Yuto, Takeuchi, Hiroshi, Tanaka, Satoshi, Tatsumi, Eri, Terui, Fuyuto, Tsukizaki, Ryudo, Wada, Koji, Yamada, Manabu, Yamada, Tetsuya, Yamamoto, Yukio, Yano, Hajime, Yokota, Yasuhiro, Yoshihara, Keisuke, Yoshikawa, Makoto, Yoshikawa, Kent, Fukai, Ryohta, Furuya, Shizuho, Hatakeda, Kentaro, Hayashi, Tasuku, Hitomi, Yuya, Kumagai, Kazuya, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Soejima, Hiromichi, Suzuki, Ayako I., Usui, Tomohiro, Yada, Toru, Yamamoto, Daiki, Yogata, Kasumi, Yoshitake, Miwa, Connolly, Jr, Harold C., Lauretta, Dante S., Yurimoto, Hisayoshi, Nagashima, Kazuhide, Kawasaki, Noriyuki, Sakamoto, Naoya, Okazaki, Ryuji, Yabuta, Hikaru, Naraoka, Hiroshi, Sakamoto, Kanako, Tachibana, Shogo, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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42. Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis

Author

Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aléon, Jérôme, O’D. Alexander, Conel M., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Published
2023
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43. Oxygen isotope evidence from Ryugu samples for early water delivery to Earth by CI chondrites

Author

Greenwood, Richard C., Franchi, Ian A., Findlay, Ross, Malley, James A., Ito, Motoo, Yamaguchi, Akira, Kimura, Makoto, Tomioka, Naotaka, Uesugi, Masayuki, Imae, Naoya, Shirai, Naoki, Ohigashi, Takuji, Liu, Ming-Chang, McCain, Kaitlyn A., Matsuda, Nozomi, McKeegan, Kevin D., Uesugi, Kentaro, Nakato, Aiko, Yogata, Kasumi, Yuzawa, Hayato, Kodama, Yu, Tsuchiyama, Akira, Yasutake, Masahiro, Hirahara, Kaori, Tekeuchi, Akihisa, Sekimoto, Shun, Sakurai, Ikuya, Okada, Ikuo, Karouji, Yuzuru, Nakazawa, Satoru, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Yoshikawa, Makoto, Miyazaki, Akiko, Nishimura, Masahiro, Yada, Toru, Abe, Masanao, Usui, Tomohiro, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2023
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44. Electronic phase diagram of Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ revealed by magnetotransport measurements

Author

Watanabe, Takao, Otsuka, Takumi, Hagisawa, Shotaro, Koshika, Yuta, Adachi, Shintaro, Usui, Tomohiro, Sasaki, Nae, Sasaki, Seya, Yamaguchi, Shunpei, Uezono, Yu, Nakanishi, Yoshiki, Yoshizawa, Masahito, and Kimura, Shojiro

Subjects
Condensed Matter - Superconductivity
Abstract

Among the Fe-based superconductors, Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ is unique in that its crystal structure is the simplest and the electron correlation level is the strongest, and thus it is important to investigate the doping($x$)-temperature ($T$) phase diagram of this system. However, inevitably incorporated excess Fe currently prevents the establishment of the true phase diagram. We overcome the aforementioned significant problem via developing a new annealing method termed as "Te-annealing" wherein single crystals are annealed under Te vapor. Specifically, we conducted various magnetotransport measurements on Te-annealed superconducting Fe$_{1+y}$Te$_{1-x}$Se$_{x}$. We observed that crossover from the incoherent to the coherent electronic state and opening of the pseudogap occurs at high temperatures ($\approx$ 150 K for $x$ = 0.2). This is accompanied by a more substantial pseudogap and the emergence of a phase with a multi-band nature at lower temperatures (below $\approx$ 50 K for $x$ = 0.2) before superconductivity sets in. Based on the results, the third type electronic phase diagram in Fe-based high-$T_c$ superconductors is revealed., Comment: 10 pages, 5 figures, Proceedings of the International conference for ECSN-2019, Odessa, Ukraine

Published
2020
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45. Transport of impact ejecta from Mars to its moons as a means to reveal Martian history

Author

Hyodo, Ryuki, Kurosawa, Kosuke, Genda, Hidenori, Usui, Tomohiro, and Fujita, Kazuhisa

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Throughout the history of the solar system, Mars has experienced continuous asteroidal impacts. These impacts have produced impact-generated Mars ejecta, and a fraction of this debris is delivered to Earth as Martian meteorites. Another fraction of the ejecta is delivered to the moons of Mars, Phobos and Deimos. Here, we studied the amount and condition of recent delivery of impact ejecta from Mars to its moons. Using state-of-the-art numerical approaches, we report, for the first time, that materials delivered from Mars to its moons are physically and chemically different from the Martian meteorites, which are all igneous rocks with a limited range of ages. We show that Mars ejecta mixed in the regolith of its moons potentially covers all its geological eras and consists of all types of rocks, from sedimentary to igneous. A Martian moons sample-return mission will bring such materials back to Earth, and the samples will provide a wealth of "time-resolved" geochemical information about the evolution of Martian surface environments., Comment: 9 pages, 3 figures, published in Scientific Reports

Published
2019
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46. Enceladus as a potential oasis for life: Science goals and investigations for future explorations

Author

Choblet, Gaël, Tobie, Gabriel, Buch, Arnaud, Čadek, Ondrej, Barge, Laura M., Bēhounková, Marie, Camprubi, Eloi, Freissinet, Caroline, Hedman, Matt, Jones, Geraint, Lainey, Valery, Le Gall, Alice, Lucchetti, Alice, MacKenzie, Shannon, Mitri, Giuseppe, Neveu, Marc, Nimmo, Francis, Olsson-Francis, Karen, Panning, Mark, Postberg, Frank, Saur, Joachim, Schmidt, Jürgen, Sekine, Yasuhito, Shibuya, Takazo, Sotin, Christophe, Soucek, Ondrej, Szopa, Cyril, Usui, Tomohiro, Vance, Steven, and Van Hoolst, Tim

Published
2022
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47. Incorporation of 16O-rich anhydrous silicates in the protolith of highly hydrated asteroid Ryugu

Author

Liu, Ming-Chang, McCain, Kaitlyn A., Matsuda, Nozomi, Yamaguchi, Akira, Kimura, Makoto, Tomioka, Naotaka, Ito, Motoo, Uesugi, Masayuki, Imae, Naoya, Shirai, Naoki, Ohigashi, Takuji, Greenwood, Richard C., Uesugi, Kentaro, Nakato, Aiko, Yogata, Kasumi, Yuzawa, Hayato, Kodama, Yu, Hirahara, Kaori, Sakurai, Ikuya, Okada, Ikuo, Karouji, Yuzuru, Nakazawa, Satoru, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Yoshikawa, Makoto, Miyazaki, Akiko, Nishimura, Masahiro, Yada, Toru, Abe, Masanao, Usui, Tomohiro, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2022
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48. A pristine record of outer Solar System materials from asteroid Ryugu’s returned sample

Author

Ito, Motoo, Tomioka, Naotaka, Uesugi, Masayuki, Yamaguchi, Akira, Shirai, Naoki, Ohigashi, Takuji, Liu, Ming-Chang, Greenwood, Richard C., Kimura, Makoto, Imae, Naoya, Uesugi, Kentaro, Nakato, Aiko, Yogata, Kasumi, Yuzawa, Hayato, Kodama, Yu, Tsuchiyama, Akira, Yasutake, Masahiro, Findlay, Ross, Franchi, Ian A., Malley, James A., McCain, Kaitlyn A., Matsuda, Nozomi, McKeegan, Kevin D., Hirahara, Kaori, Takeuchi, Akihisa, Sekimoto, Shun, Sakurai, Ikuya, Okada, Ikuo, Karouji, Yuzuru, Arakawa, Masahiko, Fujii, Atsushi, Fujimoto, Masaki, Hayakawa, Masahiko, Hirata, Naoyuki, Hirata, Naru, Honda, Rie, Honda, Chikatoshi, Hosoda, Satoshi, Iijima, Yu-ichi, Ikeda, Hitoshi, Ishiguro, Masateru, Ishihara, Yoshiaki, Iwata, Takahiro, Kawahara, Kosuke, Kikuchi, Shota, Kitazato, Kohei, Matsumoto, Koji, Matsuoka, Moe, Michikami, Tatsuhiro, Mimasu, Yuya, Miura, Akira, Mori, Osamu, Morota, Tomokatsu, Nakazawa, Satoru, Namiki, Noriyuki, Noda, Hirotomo, Noguchi, Rina, Ogawa, Naoko, Ogawa, Kazunori, Okada, Tatsuaki, Okamoto, Chisato, Ono, Go, Ozaki, Masanobu, Saiki, Takanao, Sakatani, Naoya, Sawada, Hirotaka, Senshu, Hiroki, Shimaki, Yuri, Shirai, Kei, Sugita, Seiji, Takei, Yuto, Takeuchi, Hiroshi, Tanaka, Satoshi, Tatsumi, Eri, Terui, Fuyuto, Tsukizaki, Ryudo, Wada, Koji, Yamada, Manabu, Yamada, Tetsuya, Yamamoto, Yukio, Yano, Hajime, Yokota, Yasuhiro, Yoshihara, Keisuke, Yoshikawa, Makoto, Yoshikawa, Kent, Fukai, Ryota, Furuya, Shizuho, Hatakeda, Kentaro, Hayashi, Tasuku, Hitomi, Yuya, Kumagai, Kazuya, Miyazaki, Akiko, Nishimura, Masahiro, Soejima, Hiromichi, Iwamae, Ayako, Yamamoto, Daiki, Yoshitake, Miwa, Yada, Toru, Abe, Masanao, Usui, Tomohiro, Watanabe, Sei-ichiro, and Tsuda, Yuichi

Published
2022
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49. Climate simulations of early Mars with estimated precipitation, runoff, and erosion rates

Author

Ramirez, Ramses M., Craddock, Robert A., and Usui, Tomohiro

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The debate over the early Martian climate is among the most intriguing in planetary science. Although the geologic evidence generally supports a warmer and wetter climate, climate models have had difficulty simulating such a scenario, leading some to suggest that the observed fluvial geology (e.g. valley networks, modified landscapes) on the Martian surface, could have formed in a cold climate instead. However, as we have originally predicted using a single-column radiative-convective climate model [Ramirez et al. 2014a], warming from CO2-H2 collision-induced absorption (CIA) on a volcanically active early Mars could have raised mean surface temperatures above the freezing point, with later calculations showing that this is achievable with hydrogen concentrations as low as ~1%. Nevertheless, these predictions should be tested against more complex models. Here, we use an advanced energy balance model that includes a northern lowlands ocean to show that mean surface temperatures near or slightly above the freezing point of water were necessary to carve the valley networks. Our scenario is consistent with a relatively large ocean as has been suggested. Valley network distributions would have been global prior to subsequent removal processes. At lower mean surface temperatures and smaller ocean sizes, precipitation and surface erosion efficiency diminish. The warm period may have been ~< 10 million years, perhaps suggesting that episodic warming mechanisms were not needed. Atmospheric collapse and permanently glaciated conditions occur once surface ice coverage exceeds a threshold depending on CIA assumptions. Our results support an early warm and semi-arid climate consistent with many geologic observations., Comment: Published in JGR:Planets (61 pages, 12 Figures, 2 Tables; Supp Info: 7 pages, 5 figures)

Published
2019
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50. Incoherent-coherent crossover and the pseudogap in Te-annealed superconducting Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ revealed by magnetotransport measurements

Author

Otsuka, Takumi, Hagisawa, Shotaro, Koshika, Yuta, Adachi, Shintaro, Usui, Tomohiro, Sasaki, Nae, Sasaki, Seya, Yamaguchi, Shunpei, Nakanishi, Yoshiki, Yoshizawa, Masahito, Kimura, Shojiro, and Watanabe, Takao

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Strongly Correlated Electrons
Abstract

In this study, we conducted various magnetotransport measurements on Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ single crystals from which excess iron was sufficiently removed. Our results revealed that crossover from the incoherent to the coherent electronic state and opening of the pseudogap occur at high temperatures ($\approx$ 150 K for $x$ = 0.2). This is accompanied by a more substantial pseudogap and the emergence of a phase with a multi-band nature at lower temperatures (below $\approx$ 50 K for $x$ = 0.2) before superconductivity sets in. A comparison of these results with those of the as-grown (non-superconducting) samples implies that the coherent state accompanied by the pseudogap is needed for the occurrence of superconductivity in this system., Comment: 9 pages, 7 figures

Published
2019
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