Updated on 2021/06/22

写真b

 
KAMEDA Shingo
 
*Items subject to periodic update by Rikkyo University (The rest are reprinted from information registered on researchmap.)
Affiliation*
College of Science Department of Physics
Graduate School of Science Field of Study: Physics
Graduate School of Science Field of Study: Physics
Title*
Professor
Degree
博士(理学) ( 東京大学 )
Research Theme*
  • 惑星探査機・宇宙望遠鏡に観測機器を搭載し、新たなデータを得るための技術開発を中心に研究を進めている。また、地上望遠鏡を使った惑星大気光の観測にも取り組んでいる。はやぶさ2、火星衛星探査計画MMXに参加して、データ解析、設計検討を進めながら、系外惑星大気観測装置、月惑星着陸機搭載用元素分析器の開発に力を入れている。

  • Research Interests
  • Planetary Science

  • Campus Career*
    • 4 2018 - Present 
      College of Science   Department of Physics   Professor
    • 4 2018 - Present 
      Graduate School of Science   Field of Study: Physics   Professor
    • 4 2018 - Present 
      Graduate School of Science   Field of Study: Physics   Professor
    • 4 2011 - 3 2018 
      College of Science   Department of Physics   Associate Professor
     

    Research Areas

    • Natural Science / Space and planetary sciences

    Research History

    • 4 2018 - Present 
      RIKKYO UNIVERSITY   Graduate School of Science Field of Study: Physics   Professor

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    • 4 2018 - Present 
      RIKKYO UNIVERSITY   Graduate School of Science Field of Study: Physics   Professor

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    • 4 2018 - Present 
      RIKKYO UNIVERSITY   College of Science Department of Physics   Professor

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    • 4 2011 - 3 2018 
      RIKKYO UNIVERSITY   College of Science Department of Physics   Associate Professor

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    Education

    • 4 2004 - 3 2007 
      The University of Tokyo   Graduate School, Division of Science   Department of Earth and Planetary Science

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      Country: Japan

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    • 4 2004 - 3 2007 
      The University of Tokyo   Graduate School, Division of Science   Department of Earth and Planetary Science

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      Country: Japan

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    • 4 2002 - 3 2004 
      The University of Tokyo   Graduate School, Division of Science   Department of Earth and Planetary Science

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      Country: Japan

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    • 4 2002 - 3 2004 
      The University of Tokyo   Graduate School, Division of Science   Department of Earth and Planetary Science

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      Country: Japan

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    • 4 1997 - 3 2002 
      The University of Tokyo   Faculty of Science   Department of Earth and Planetary Science

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      Country: Japan

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    Papers

    • Surface roughness of asteroid (162173) Ryugu and comet 67P/Churyumov-Gerasimenko inferred from in-situ observations Peer-reviewed

      K A Otto, K-D Matz, S E Schröder, R Parekh, K Krohn, R Honda, S Kameda, R Jaumann, N Schmitz, K Stephan, S Sugita, E Tatsumi, T-M Ho, A Koncz, F Trauthan, Y Cho, M Hayakawa, C Honda, T Kouyama, M Matsuoka, T Morota, S Mottola, K Ogawa, F Preusker, N Sakatani, H Sawada, F Scholten, H Suzuki, M Yamada, Y Yokota, K Yoshioka

      Monthly Notices of the Royal Astronomical Society   27 10 2020

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      Publishing type:Research paper (scientific journal)   Publisher:Oxford University Press (OUP)  

      <title>Abstract</title>
      Alteration processes on asteroid and comet surfaces, such as thermal fracturing, (micrometeorite) impacts or volatile outgassing, are complex mechanisms that form diverse surface morphologies and roughness on various scales. These mechanisms and their interaction may differ on the surfaces of different bodies. Asteroid Ryugu and comet 67P/Churyumov-Gerasimenko, both, have been visited by landers which imaged the surfaces in high spatial resolution. We investigate the surface morphology and roughness of Ryugu and 67P/Churyumov-Gerasimenko based on high resolution in situ images of 0.2 mm and 0.8 mm pixel resolution over an approximately 25 cm and 80 cm wide scene, respectively. To maintain comparability and reproducibility, we introduce a method to extract surface roughness descriptors (fractal dimension, Hurst exponent, joint roughness coefficient, root mean square slope, hemispherical crater density, small scale roughness parameter and Hapke mean slope angle) from in situ planetary images illuminated by LEDs. We validate our method and choose adequate parameters for an analysis of the roughness of the surfaces. We also derive the roughness descriptors from 3-dimensional shape models of Ryugu and orbiter camera images and show that the higher spatially resolved images results in a higher roughness. We find that 67P/Churyumov-Gerasimenko is up to 6% rougher than Ryugu depending on the descriptor used and attribute this difference to the different intrinsic properties of the materials imaged and the erosive processes altering them. On 67P/Churyumov-Gerasimenko sublimation appears to be the main cause for roughness, while on Ryugu micrometeoroid bombardment as well as thermal fatigue and solar weathering may play a significant role in shaping the surface.

      DOI: 10.1093/mnras/staa3314

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    • Hayabusa2 Landing Site Selection: Surface Topography of Ryugu and Touchdown Safety Peer-reviewed

      Shota Kikuchi, Sei-ichiro Watanabe, Takanao Saiki, Hikaru Yabuta, Seiji Sugita, Tomokatsu Morota, Naru Hirata, Naoyuki Hirata, Tatsuhiro Michikami, Chikatoshi Honda, Yashuhiro Yokota, Rie Honda, Naoya Sakatani, Tatsuaki Okada, Yuri Shimaki, Koji Matsumoto, Rina Noguchi, Yuto Takei, Fuyuto Terui, Naoko Ogawa, Kent Yoshikawa, Go Ono, Yuya Mimasu, Hirotaka Sawada, Hitoshi Ikeda, Chikako Hirose, Tadateru Takahashi, Atsushi Fujii, Tomohiro Yamaguchi, Yoshiaki Ishihara, Tomoki Nakamura, Kohei Kitazato, Koji Wada, Shogo Tachibana, Eri Tatsumi, Moe Matsuoka, Hiroki Senshu, Shingo Kameda, Toru Kouyama, Manabu Yamada, Kei Shirai, Yuichiro Cho, Kazunori Ogawa, Yukio Yamamoto, Akira Miura, Takahiro Iwata, Noriyuki Namiki, Masahiko Hayakawa, Masanao Abe, Satoshi Tanaka, Makoto Yoshikawa, Satoru Nakazawa, Yuichi Tsuda

      Space Science Reviews216 ( 7 )   10 2020

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      Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

      DOI: 10.1007/s11214-020-00737-z

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      Other Link: http://link.springer.com/article/10.1007/s11214-020-00737-z/fulltext.html

    • Collisional history of Ryugu’s parent body from bright surface boulders Peer-reviewed

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

      Nature Astronomy   21 9 2020

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      Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

      DOI: 10.1038/s41550-020-1179-z

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      Other Link: http://www.nature.com/articles/s41550-020-1179-z

    • Global photometric properties of (162173) Ryugu Peer-reviewed

      E. Tatsumi, D. Domingue, S. Schröder, Y. Yokota, D. Kuroda, M. Ishiguro, S. Hasegawa, T. Hiroi, R. Honda, R. Hemmi, L. Le Corre, N. Sakatani, T. Morota, M. Yamada, S. Kameda, T. Koyama, H. Suzuki, Y. Cho, K. Yoshioka, M. Matsuoka, C. Honda, M. Hayakawa, N. Hirata, N. Hirata, Y. Yamamoto, F. Vilas, N. Takato, M. Yoshikawa, M. Abe, S. Sugita

      Astronomy & Astrophysics639   A83 - A83   7 2020

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      Publishing type:Research paper (scientific journal)   Publisher:EDP Sciences  

      <italic>Context.</italic> The Hayabusa2 spacecraft launched by Japan Aerospace Exploration Agency has been conducting observations of the asteroid (162173) Ryugu since June 2018. The Telescopic Optical Navigation Camera (ONC-T) onboard Hayabusa2 has obtained thousands of images under a variety of illumination and viewing conditions.


      <italic>Aims.</italic> Our objective is to examine and validate the camera calibration, derive a photometric correction for creating global albedo maps, and to interpret the photometric modeling results to characterize the surface of Ryugu.


      <italic>Methods.</italic> We observed (162173) Ryugu with the Gemini-South telescope, and combined these measurements with other published ground-based observations of the asteroid. The ground-based observations were compared with the data obtained by ONC-T in order to validate the radiometric calibration mutually. We used a combination of the Hapke disk-integrated and disk-resolved model equations to simultaneously analyze the combined ground- and spacecraft-based data.


      <italic>Results.</italic> The average spectrum of Ryugu was classified as Cb-type following the SMASSII taxonomy and C/F-type following the Tholen taxonomy based on spacecraft observations. We derived Hapke model parameters for all seven color filters, which allowed us to photometrically correct images to within an error of &lt;10% for ~80% of the image pixels used in the modeling effort. Using this model, we derived a geometric albedo of 4.0 ± 0.5% (<italic>v</italic> band) for Ryugu. The average reflectance factor at the standard illumination condition was 1.87 ± 0.14% in the <italic>v</italic> band. Moreover we measured a phase reddening of (2.0 ± 0.7) × 10<sup>−3</sup> <italic>μ</italic>m<sup>−1</sup> deg<sup>−1</sup> for Ryugu, similar to that observed for the asteroid (101955) Bennu.


      <italic>Conclusions.</italic> The global color map showed that the general trend was for darker regions to also be redder regions, however there were some distinct exceptions to this trend. For example, Otohime Saxum was bright and red while Kibidango crater was dark and blue. The darkness and flatness of Ryugu’s reflectance might be caused by a high abundance of organic materials.

      DOI: 10.1051/0004-6361/201937096

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    • Sample collection from asteroid (162173) Ryugu by Hayabusa2: Implications for surface evolution Peer-reviewed

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

      Science368 ( 6491 ) 654 - 659   8 5 2020

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      Publishing type:Research paper (scientific journal)   Publisher:American Association for the Advancement of Science (AAAS)  

      The near-Earth asteroid (162173) Ryugu is thought to be a primitive carbonaceous object that contains hydrated minerals and organic molecules. We report sample collection from Ryugu’s surface by the Hayabusa2 spacecraft on 21 February 2019. Touchdown images and global observations of surface colors are used to investigate the stratigraphy of the surface around the sample location and across Ryugu. Latitudinal color variations suggest the reddening of exposed surface material by solar heating and/or space weathering. Immediately after touchdown, Hayabusa2’s thrusters disturbed dark, fine grains that originate from the redder materials. The stratigraphic relationship between identified craters and the redder material indicates that surface reddening occurred over a short period of time. We suggest that Ryugu previously experienced an orbital excursion near the Sun.

      DOI: 10.1126/science.aaz6306

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    • An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime Peer-reviewed

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

      Science368 ( 6486 ) 67 - 71   3 4 2020

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      Publishing type:Research paper (scientific journal)   Publisher:American Association for the Advancement of Science (AAAS)  

      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 &gt;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 &gt;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.

      DOI: 10.1126/science.aaz1701

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    • The spatial distribution of impact craters on Ryugu Peer-reviewed

      Naoyuki Hirata, Tomokatsu Morota, Yuichiro Cho, Masanori Kanamaru, Sei-ichiro Watanabe, Seiji Sugita, Naru Hirata, Yukio Yamamoto, Rina Noguchi, Yuri Shimaki, Eri Tatsumi, Kazuo Yoshioka, Hirotaka Sawada, Yasuhiro Yokota, Naoya Sakatani, Masahiko Hayakawa, Moe Matsuoka, Rie Honda, Shingo Kameda, Manabu Yamada, Toru Kouyama, Hidehiko Suzuki, Chikatoshi Honda, Kazunori Ogawa, Yuichi Tsuda, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Shota Kikuchi, Tomohiro Yamaguchi, Naoko Ogawa, Go Ono, Yuya Mimasu, Kent Yoshikawa, Tadateru Takahashi, Yuto Takei, Atsushi Fujii, Hiroshi Takeuchi, Tatsuaki Okada, Kei Shirai, Yu-ichi Iijima

      Icarus338   113527 - 113527   3 2020

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      Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

      DOI: 10.1016/j.icarus.2019.113527

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    • The Hayabusa2 lander MASCOT on the surface of asteroid (162173) Ryugu – Stereo-photogrammetric analysis of MASCam image data Peer-reviewed

      F. Scholten, F. Preusker, S. Elgner, K.-D. Matz, R. Jaumann, M. Hamm, S. E. Schröder, A. Koncz, N. Schmitz, F. Trauthan, M. Grott, J. Biele, T.-M. Ho, S. Kameda, S. Sugita

      Astronomy & Astrophysics632   L5 - L5   12 2019

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      Publishing type:Research paper (scientific journal)   Publisher:EDP Sciences  

      After its release and a descent and bouncing phase, the Hayabusa2 lander MASCOT came to a final rest and MASCOT’s camera MASCam acquired a set of images of the surface of Ryugu. With MASCam’s instantaneous field of view of about 1 mrad, the images provide pixel scales from 0.2 to 0.5 mm pixel<sup>−1</sup> in the foreground and up to 1 cm pixel<sup>−1</sup> for surface parts in the background. Using a stereo-photogrammetric analysis of the MASCam images taken from slightly different positions due to commanded and unintentional movements of the MASCOT lander, we were able to determine the orientation for the different measurement positions. Furthermore, we derived a 3D surface model of MASCOT’s vicinity. Although the conditions for 3D stereo processing were poor due to very small stereo angles, the derived 3D model has about 0.5 cm accuracy in the foreground at 20 cm distance and about 1.5 cm at a distance of 40–50 cm.

      DOI: 10.1051/0004-6361/201936760

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    • The MASCOT landing area on asteroid (162173) Ryugu: Stereo-photogrammetric analysis using images of the ONC onboard the Hayabusa2 spacecraft Peer-reviewed

      F. Preusker, F. Scholten, S. Elgner, K.-D. Matz, S. Kameda, T. Roatsch, R. Jaumann, S. Sugita, R. Honda, T. Morota, E. Tatsumi, Y. Cho, K. Yoshioka, H. Sawada, Y. Yokota, N. Sakatani, M. Hayakawa, M. Matsuoka, M. Yamada, T. Kouyama, H. Suzuki, C. Honda, K. Ogawa

      Astronomy & Astrophysics632   L4 - L4   12 2019

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      Publishing type:Research paper (scientific journal)   Publisher:EDP Sciences  

      A high-resolution 3D surface model, map-projected to a digital terrain model (DTM), and precisely ortho-rectified context images (orthoimages) of MASCOT landing site area are important data sets for the scientific analysis of relevant data that have been acquired with MASCOT’s image camera system MASCam and other instruments (e.g., the radiometer MARA and the magnetometer MASMag). We performed a stereo-photogrammetric (SPG) analysis of 1050 images acquired from the Hayabusa2 Optical Navigation Camera system (ONC) during the asteroid characterization phase and the MASCOT release phase in early October 2018 to construct a photogrammetric control point network of asteroid (162173) Ryugu. We validated existing rotational parameters for Ryugu and improved the camera orientation (position and pointing) of the ONC images to decimeter accuracy using SPG bundle block adjustment. We produced a high-resolution DTM of the entire MASCOT landing site area. Finally, based on this DTM, a set of orthoimages from the highest-resolution ONC images around MASCOT’s final rest position complements the results of this analysis.

      DOI: 10.1051/0004-6361/201936759

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    • The descent and bouncing path of the Hayabusa2 lander MASCOT at asteroid (162173) Ryugu Peer-reviewed

      F. Scholten, F. Preusker, S. Elgner, K.-D. Matz, R. Jaumann, J. Biele, D. Hercik, H.-U. Auster, M. Hamm, M. Grott, C. Grimm, T.-M. Ho, A. Koncz, N. Schmitz, F. Trauthan, S. Kameda, S. Sugita, R. Honda, T. Morota, E. Tatsumi, Y. Cho, K. Yoshioka, H. Sawada, Y. Yokota, N. Sakatani, M. Hayakawa, M. Matsuoka, M. Yamada, T. Kouyama, H. Suzuki, C. Honda, K. Ogawa

      Astronomy & Astrophysics632   L3 - L3   12 2019

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      Publishing type:Research paper (scientific journal)   Publisher:EDP Sciences  

      Images from the Optical Navigation Camera system (ONC) onboard the Hayabusa2 spacecraft show the MASCOT lander during its descent to the surface of asteroid (162173) Ryugu. We used results from a previous stereo-photogrammetric analysis that provided precise ONC image orientation data (camera position and pointing), ONC orthoimages, and an ONC-based 3D surface model to combine them with the visibilities of MASCOT itself and its shadow on-ground within the ONC images. We integrated additional information from instruments onboard MASCOT (MASMag, MARA, MASCam) and derived MASCOT’s release position and modeled its free-fall descent path and its velocity over 350 s from its release at ∼41 m altitude above ground until its first contact with the surface of Ryugu. After first contact, MASCOT bounced over the surface of Ryugu for 663 s and came to rest at its first settlement point after four intermediate surface contacts. We again used ONC images that show MASCOT and partly its shadow and reconstructed the bouncing path and the respective velocities of MASCOT. The achieved accuracy for the entire descent and bouncing path is ∼0.1 m (1<italic>σ</italic>).

      DOI: 10.1051/0004-6361/201936757

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    • Earth as an exoplanet mission concept for a lunar orbiting cubesat Peer-reviewed

      Ana I. Gómez de Castro, Leire Beitia-Antero, Carlos E. Miravet-Fuster, Lorenzo Tarabini, Albert Tomás, Juan C. Vallejo, Ada Canet, Mikhail Sachkov, Shingo Kameda

      Journal of Astronomical Telescopes, Instruments, and Systems5 ( 04 ) 1 - 1   23 10 2019

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      Publishing type:Research paper (scientific journal)   Publisher:SPIE-Intl Soc Optical Eng  

      DOI: 10.1117/1.jatis.5.4.044004

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    • Boulder size and shape distributions on asteroid Ryugu Peer-reviewed

      Tatsuhiro Michikami, Chikatoshi Honda, Hideaki Miyamoto, Masatoshi Hirabayashi, Axel Hagermann, Terunori Irie, Keita Nomura, Carolyn M. Ernst, Masaki Kawamura, Kiichi Sugimoto, Eri Tatsumi, Tomokatsu Morota, Naru Hirata, Takaaki Noguchi, Yuichiro Cho, Shingo Kameda, Toru Kouyama, Yasuhiro Yokota, Rina Noguchi, Masahiko Hayakawa, Naoyuki Hirata, Rie Honda, Moe Matsuoka, Naoya Sakatani, Hidehiko Suzuki, Manabu Yamada, Kazuo Yoshioka, Hirotaka Sawada, Ryodo Hemmi, Hiroshi Kikuchi, Kazunori Ogawa, Sei-ichiro Watanabe, Satoshi Tanaka, Makoto Yoshikawa, Yuichi Tsuda, Seiji Sugita

      Icarus331   179 - 191   10 2019

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      Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

      DOI: 10.1016/j.icarus.2019.05.019

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    • Development of high-efficiency reflective grating by holographic processing for UV exoplanet science Peer-reviewed

      K. Enya, S. Kameda

      Proceedings of the SPIE   9 9 2019

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      Language:English   Publishing type:Research paper (international conference proceedings)  

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    • Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites Peer-reviewed

      R. Jaumann, N. Schmitz, T. M. Ho, S. E. Schröder, K. A. Otto, K. Stephan, S. Elgner, K. Krohn, F. Preusker, F. Scholten, J. Biele, S. Ulamec, C. Krause, S. Sugita, K. D. Matz, T. Roatsch, R. Parekh, S. Mottola, M. Grott, P. Michel, F. Trauthan, A. Koncz, H. Michaelis, C. Lange, J. T. Grundmann, M. Maibaum, K. Sasaki, F. Wolff, J. Reill, A. Moussi-Soffys, L. Lorda, W. Neumann, J. B. Vincent, R. Wagner, J. P. Bibring, S. Kameda, H. Yano, S. Watanabe, M. Yoshikawa, Y. Tsuda, T. Okada, T. Yoshimitsu, Y. Mimasu, T. Saiki, H. Yabuta, H. Rauer, R. Honda, T. Morota, Y. Yokota, T. Kouyama

      Science365 ( 6455 ) 817 - 820   23 8 2019

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      Language:English   Publishing type:Research paper (scientific journal)  

      © 2017 The Authors. The near-Earth asteroid (162173) Ryugu is a 900-m-diameter dark object expected to contain primordial material from the solar nebula. The Mobile Asteroid Surface Scout (MASCOT) landed on Ryugu’s surface on 3 October 2018. We present images from the MASCOT camera (MASCam) taken during the descent and while on the surface. The surface is covered by decimeter- to meter-sized rocks, with no deposits of fine-grained material. Rocks appear either bright, with smooth faces and sharp edges, or dark, with a cauliflower-like, crumbly surface. Close-up images of a rock of the latter type reveal a dark matrix with small, bright, spectrally different inclusions, implying that it did not experience extensive aqueous alteration. The inclusions appear similar to those in carbonaceous chondrite meteorites.

      DOI: 10.1126/science.aaw8627

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    • Multivariable statistical analysis of spectrophotometry and spectra of (162173) Ryugu as observed by JAXA Hayabusa2 mission Peer-reviewed

      M. Barucci, S. Kameda他

      Astronomy & Astrophysics   23 8 2019

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      Language:English   Publishing type:Research paper (scientific journal)  

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    • RYUGU'S PARENT-BODY PROCESSES ESTIMATED FROM HAYABUSA2 MULTI-BAND OPTICAL OBSERVATIONS

      Sugita S, Honda R, Morota T, Kameda S, Tatsumi E, Honda C, Yokota Y, Yamada M, Kouyama T, Sakatani N, Suzuki H, Yoshioka K, Cho Y, Matsuoka M, Ogawa K, Domingue D, Miyamoto H, Barnouin O. S, Michel P, Ernst C. M, Hiroi T, Nakamura T, Sawada H, Hayakawa M, Hirata N, Hirata N, Kikuchi H, Hemmi R, Michikami T, Palmer Eric, Gaskell R, Hirabayashi M, Jaumann R, Otto K, Schmitz N, Schroder S. E, Komatsu G, Tanaka S, Shirai K, Yoshikawa M, Watanabe S, Tsuda Y

      METEORITICS & PLANETARY SCIENCE54   .   8 2019

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      Language:English   Publishing type:Research paper (scientific journal)  

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    • Updated inflight calibration of Hayabusa2's optical navigation camera (ONC) for scientific observations during the cruise phase Peer-reviewed

      Eri Tatsumi, Toru Kouyama, Hidehiko Suzuki, Manabu Yamada, Naoya Sakatani, Shingo Kameda, Yasuhiro Yokota, Rie Honda, Tomokatsu Morota, Keiichi Moroi, Naoya Tanabe, Hiroaki Kamiyoshihara, Marika Ishida, Kazuo Yoshioka, Hiroyuki Sato, Chikatoshi Honda, Masahiko Hayakawa, Kohei Kitazato, Hirotaka Sawada, Seiji Sugita

      Icarus325   153 - 195   6 2019

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier {BV}  

      DOI: 10.1016/j.icarus.2019.01.015

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    • Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu-A spinning top-shaped rubble pile. Peer-reviewed International journal

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

      Science (New York, N.Y.)364 ( 6437 ) 268 - 272   19 4 2019

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      The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.

      DOI: 10.1126/science.aav8032

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    • The Western Bulge of 162173 Ryugu Formed as a Result of a Rotationally Driven Deformation Process

      Masatoshi Hirabayashi, Eri Tatsumi, Hideaki Miyamoto, Goro Komatsu, Seiji Sugita, Sei Ichiro Watanabe, Daniel J. Scheeres, Olivier S. Barnouin, Patrick Michel, Chikatoshi Honda, Tatsuhiro Michikami, Yuichiro Cho, Tomokatsu Morota, Naru Hirata, Naoyuki Hirata, Naoya Sakatani, Stephen R. Schwartz, Rie Honda, Yasuhiro Yokota, Shingo Kameda, Hidehiko Suzuki, Toru Kouyama, Masahiko Hayakawa, Moe Matsuoka, Kazuo Yoshioka, Kazunori Ogawa, Hirotaka Sawada, Makoto Yoshikawa, Yuichi Tsuda

      Astrophysical Journal Letters874 ( 1 )   20 3 2019

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      © 2019. The American Astronomical Society. All rights reserved.. 162173 Ryugu, the target of Hayabusa2, has a round shape with an equatorial ridge, which is known as a spinning top shape. A strong centrifugal force is a likely contributor to Ryugu's top-shaped features. Observations by the Optical Navigation Camera on board Hayabusa2 show a unique longitudinal variation in geomorphology; the western side of this asteroid, later called the western bulge, has a smooth surface and a sharp equatorial ridge, compared to the other side. Here, we propose a structural deformation process that generated the western bulge. Applying the mission-derived shape model, we employ a finite element model technique to analyze the locations that experience structural failure within the present shape. Assuming that materials are uniformly distributed, our model shows the longitudinal variation in structurally failed regions when the spin period is shorter than ∼3.75 hr. Ryugu is structurally intact in the subsurface region of the western bulge while other regions are sensitive to structural failure. We infer that this variation is indicative of the deformation process that occurred in the past, and the western bulge is more relaxed structurally than the other region. Our analysis also shows that this deformation process might occur at a spin period between ∼3.5 and ∼3.0 hr, providing the cohesive strength ranging between ∼4 and ∼10 Pa.

      DOI: 10.3847/2041-8213/ab0e8b

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    • Surface Physical Condition of Asteroid Ryugu Using Close-up Optical and Thermal Images

      Sakatani, N, Sugita, S, Honda, R, Morota, T, Yamada, M, Kameda, S, Tatsumi, E, Yokota, Y, Kouyama, T, Suzuki, H, Honda, C, Hayakawa, M, Yoshioka, K, Matsuoka, M, Cho, Y, Sawada, H, Ogawa, N, Miura, A, Okada, T, Tanaka, S, Senshu, H, Arai, T, Demura, H, Suko, K, Shimaki, Y, Sekiguchi, T, Takita, J, Fukuhara, T, Taguchi, M, Mueller, T, Hagermann, A, Biele, J, Grott, M, Delbo, M

      50th Lunar and Planetary Science Conference2132   1732 - 1733   3 2019

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:The Lunar and Planetary Institute  

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    • The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes Peer-reviewed

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

      Science364 ( 6437 )   2019

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      DOI: 10.1126/science.aaw0422

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    • The surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy Peer-reviewed

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

      Science364 ( 6437 ) 272 - 275   2019

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      Language:English   Publishing type:Research paper (scientific journal)  

      © 2019 American Association for the Advancement of Science. All rights reserved. The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu's surface acquired with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.

      DOI: 10.1126/science.aav7432

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    • Observability of hydrogen-rich exospheres in Earth-like exoplanets Peer-reviewed

      Leonardo A. dos, Santos, Vincent Bourrier, David Ehrenreich, Shingo Kameda

      Astronomy & Astrophysics   28 11 2018

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    • A chemical survey of exoplanets with ARIEL Peer-reviewed

      Giovanna Tinetti, Pierre Drossart, Paul Eccleston, Paul Hartogh, Astrid Heske, Jeremy Leconte, Giusi Micela, Marc Ollivier, Goran Pilbratt, Ludovic Puig, Diego Turrini, Bart Vandenbussche, Paulina Wolkenberg, Jean-Philippe Beaulieu, Lars A. Buchave, Martin Ferus, Matt Griffin, Manuel Guedel, Kay Justtanont, Pierre-Olivier Lagage, Pedro Machado, Giuseppe Malaguti, Michiel Min, Hans Ulrik Norgaard-Nielsen, Mirek Rataj, Tom Ray, Ignasi Ribas, Mark Swain, Robert Szabo, Stephanie Werner, Joanna Barstow, Matt Burleigh, James Cho, Vincent Coude du Foresto, Athena Coustenis, Leen Decin, Therese Encrenaz, Marina Galand, Michael Gillon, Ravit Helled, Juan Carlos Morales, Antonio Garcia Munoz, Andrea Moneti, Isabella Pagano, Enzo Pascale, Giuseppe Piccioni, David Pinfield, Subhajit Sarkar, Franck Selsis, Jonathan Tennyson, Amaury Triaud, Olivia Venot, Ingo Waldmann, David Waltham, Gillian Wright, Jerome Amiaux, Jean-Louis Augueres, Michel Berthe, Naidu Bezawada, Georgia Bishop, Neil Bowles, Deirdre Coffey, Josep Colome, Martin Crook, Pierre-Elie Crouzet, Vania Da Peppo, Isabel Escudero Sanz, Mauro Focardi, Martin Frericks, Tom Hunt, Ralf Kohley, Kevin Middleton, Gianluca Morgante, Roland Ottensamer, Emanuele Pace, Chris Pearson, Richard Stamper, Kate Symonds, Miriam Rengel, Etienne Renotte, Peter Ade, Laura Affer, Christophe Alard, Nicole Allard, Francesca Altieri, Yves Andre, Claudio Arena, Ioannis Argyriou, Alan Aylward, Cristian Baccani, Gaspar Bakos, Marek Banaszkiewicz, Mike Barlow, Virginie Batista, Giancarlo Bellucci, Serena Benatti, Pernelle Bernardi, Bruno Bezard, Maria Blecka, Emeline Bolmont, Bertrand Bonfond, Rosaria Bonito, Aldo S. Bonomo, John Robert Brucato, Allan Sacha Brun, Ian Bryson, Waldemar Bujwan, Sarah Casewell, Bejamin Charnay, Cesare Cecchi Pestellini, Guo Chen, Angela Ciaravella, Riccardo Claudi, Rodolphe Cledassou, Mario Damasso, Mario Damiano, Camilla Danielski, Pieter Deroo, Anna Maria Di Giorgio, Carsten Dominik, Vanessa Doublier, Simon Doyle, Rene Doyon, Benjamin Drummond, Bastien Duong, Stephen Eales, Billy Edwards, Maria Farina, Ettore Flaccomio, Leigh Fletcher, Francois Forget, Steve Fossey, Markus Fraenz, Yuka Fujii, Alvaro Garcia-Piquer, Walter Gear, Herve Geoffray, Jean Claude Gerard, Lluis Gesa, H. Gomez, Rafal Graczyk, Caitlin Griffith, Denis Grodent, Mario Giuseppe Guarcello, Jacques Gustin, Keiko Hamano, Peter Hargrave, Yann Hello, Kevin Heng, Enrique Herrero, Allan Hornstrup, Benoit Hubert, Shigeru Ida, Masahiro Ikoma, Nicolas Iro, Patrick Irwin, Christopher Jarchow, Jean Jaubert, Hugh Jones, Queyrel Julien, Shingo Kameda, Franz Kerschbaum, Pierre Kervella, Tommi Koskinen, Matthijs Krijger, Norbert Krupp, Marina Lafarga, Federico Landini, Emanuel Lellouch, Giuseppe Leto, A. Luntzer, Theresa Rank-Luftinger, Antonio Maggio, Jesus Maldonado, Jean-Pierre Maillard, Urs Mall, Jean-Baptiste Marquette, Stephane Mathis, Pierre Maxted, Taro Matsuo, Alexander Medvedev, Yamila Miguel, Vincent Minier, Giuseppe Morello, Alessandro Mura, Norio Narita, Valerio Nascimbeni, N. Nguyen Tong, Vladimiro Noce, Fabrizio Oliva, Enric Palle, Paul Palmer, Maurizio Pancrazzi, Andreas Papageorgiou, Vivien Parmentier, Manuel Perger, Antonino Petralia, Stefano Pezzuto, Ray Pierrehumbert, Ignazio Pillitteri, Giampaolo Piotto, Giampaolo Pisano, Loredana Prisinzano, Aikaterini Radioti, Jean-Michel Reess, Ladislav Rezac, Marco Rocchetto, Albert Rosich, Nicoletta Sanna, Alexandre Santerne, Giorgio Savini, Gaetano Scandariato, Bruno Sicardy, Carles Sierra, Giuseppe Sindoni, Konrad Skup, Ignas Snellen, Mateusz Sobiecki, Lauriane Soret, Alessandro Sozzetti, A. Stiepen, Antoine Strugarek, Jake Taylor, William Taylor, Luca Terenzi, Marcell Tessenyi, Angelos Tsiaras, C. Tucker, Diana Valencia, Gautam Vasisht, Allona Vazan, Francesc Vilardell, Sabrine Vinatier, Serena Viti, Rens Waters, Piotr Wawer, Anna Wawrzaszek, Anthony Whitworth, Yuk L. Yung, Sergey N. Yurchenko, Maria Rosa Zapatero Osorio, Robert Zellem, Tiziano Zingales, Frans Zwart

      EXPERIMENTAL ASTRONOMY46 ( 1 ) 135 - 209   11 2018

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER  

      Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet's birth, and evolution. ARIEL was conceived to observe a large number (1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25-7.8m spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10-100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed - using conservative estimates of mission performance and a full model of all significant noise sources in the measurement - using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL - in line with the stated mission objectives - will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.

      DOI: 10.1007/s10686-018-9598-x

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    • Stellar imaging coronagraph and exoplanet coronal spectrometer: two additional instruments for exoplanet exploration onboard the WSO-UV 1.7-m orbital telescope Peer-reviewed

      Alexander Tavrov, Shingo Kameda, Andrey Yudaev, Ilia Dzyuban, Alexander Kiselev, Inna Shashkova, Oleg Korablev, Mikhail Sachkov, Jun Nishikawa, Motohide Tamura, Go Murakami, Keigo Enya, Masahiro Ikoma, Norio Narita

      Journal of Astronomical Telescopes, Instruments, and Systems   1 10 2018

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    • Evaluation of hydrogen absorption cells for observations of the planetary coronas Peer-reviewed

      M. Kuwabara, M. Taguchi, K. Yoshioka, T. Ishida, N. de Oliveira, K. Ito, S. Kameda, F. Suzuki, I. Yoshikawa

      Review of Scientific Instruments   15 2 2018

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    • Initial products of Akatsuki 1-μm camera Peer-reviewed

      Iwagami, Naomoto, Sakanoi, Takeshi, Hashimoto, George L, Kameda, Shingo他

      Earth, Planets and Space   11 1 2018

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    • Initial inflight calibration for Hayabusa2 optical navigation camera (ONC) for science observations of asteroid Ryugu Peer-reviewed

      H. Suzuki, M. Yamada, T. Kouyama, E. Tatsumi, S. Kameda, R. Honda, H. Sawada, N. Ogawa, T. Morota, C. Honda, N. Sakatani, M. Hayakawa, Y. Yokota, Y. Yamamoto, S. Sugita

      ICARUS300   341 - 359   1 2018

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:ACADEMIC PRESS INC ELSEVIER SCIENCE  

      Hayabusa2, the first sample return mission to a C-type asteroid was launched by the Japan Aerospace Exploration Agency (JAXA) on December 3, 2014 and will arrive at the asteroid in the middle of 2018 to collect samples from its surface, which may contain both hydrated minerals and organics. The optical navigation camera (ONC) system on board the Hayabusa2 consists of three individual framing CCD cameras, ONC-T for a telescopic nadir view, ONC-W1 for a wide-angle nadir view, and ONC-W2 for a wide-angle slant view will be used to observe the surface of Ryugu. The cameras will be used to measure the global asteroid shape, local morphologies, and visible spectroscopic properties. Thus, image data obtained by ONC will provide essential information to select landing (sampling) sites on the asteroid. This study reports the results of initial inflight calibration based on observations of Earth, Mars, Moon, and stars to verify and characterize the optical performance of the ONC, such as flat-field sensitivity, spectral sensitivity, point-spread function (PSF), distortion, and stray light of ONC-T, and distortion for ONC-W1 and W2. We found some potential problems that may influence our science observations. This includes changes in sensitivity of flat fields for all bands from those that were measured in the pre-flight calibration and existence of a stray light that arises under certain conditions of spacecraft attitude with respect to the sun. The countermeasures for these problems were evaluated by using data obtained during initial in-flight calibration. The results of our inflight calibration indicate that the error of spectroscopic measurements around 0.7 mu m using 0.55, 0.70, and 0.86 mu m bands of the ONC-T can be lower than 0.7% after these countermeasures and pixel binning. This result suggests that our ONC-T would be able to detect typical strength (similar to 3%) of the serpentine absorption band often found on CM chondrites and low albedo asteroids with &gt;= 4 sigma confidence. (C) 2017 Elsevier Inc. All rights reserved.

      DOI: 10.1016/j.icarus.2017.09.11

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    • Overview of Akatsuki data products: definition of data levels, method and accuracy of geometric correction Peer-reviewed

      Kazunori Ogohara, Masahiro Takagi, Shin-ya Murakami, Takeshi Horinouchi, Manabu Yamada, Toru Kouyama, George L. Hashimoto, Takeshi Imamura, Yukio Yamamoto, Hiroki Kashimura, Naru Hirata, Naoki Sato, Atsushi Yamazaki, Takehiko Satoh, Naomoto Iwagami, Makoto Taguchi, Shigeto Watanabe, Takao M. Sato, Shoko Ohtsuki, Tetsuya Fukuhara, Masahiko Futaguchi, Takeshi Sakanoi, Shingo Kameda, Ko-ichiro Sugiyama, Hiroki Ando, Yeon Joo Lee, Masato Nakamura, Makoto Suzuki, Chikako Hirose, Nobuaki Ishii, Takumi Abe

      EARTH PLANETS AND SPACE69   12 2017

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER HEIDELBERG  

      We provide an overview of data products from observations by the Japanese Venus Climate Orbiter, Akatsuki, and describe the definition and content of each data-processing level. Levels 1 and 2 consist of non-calibrated and calibrated radiance (or brightness temperature), respectively, as well as geometry information (e.g., illumination angles). Level 3 data are global-grid data in the regular longitude-latitude coordinate system, produced from the contents of Level 2. Non-negligible errors in navigational data and instrumental alignment can result in serious errors in the geometry calculations. Such errors cause mismapping of the data and lead to inconsistencies between radiances and illumination angles, along with errors in cloud-motion vectors. Thus, we carefully correct the boresight pointing of each camera by fitting an ellipse to the observed Venusian limb to provide improved longitude-latitude maps for Level 3 products, if possible. The accuracy of the pointing correction is also estimated statistically by simulating observed limb distributions. The results show that our algorithm successfully corrects instrumental pointing and will enable a variety of studies on the Venusian atmosphere using Akatsuki data.

      DOI: 10.1186/s40623-017-0749-5

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    • Ecliptic North-South Symmetry of Hydrogen Geocorona Peer-reviewed

      Kameda, S, Ikezawa, S, Sato, M, Kuwabara, M, Osada, N, Murakami, G, Yoshioka, K, Yoshikawa, I, Taguchi, M, Funase, R, Sugita, S, Miyoshi, Y, Fujimoto, M

      Geophysical Research Letters   9 11 2017

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    • Experimental characterization of elastomeric O-rings as reusable seals for mass spectrometric measurements: Application to in situ K-Ar dating on Mars Peer-reviewed

      Yuichiro Cho, Shingo Kameda, Mamoru Okuno, Misa Horiuchi, Kazuo Shibasaki, Ryo Wagatsuma, Yusuke Aida, Yayoi N. Miura, Kazuo Yoshioka, Ryuji Okazaki, Seiji Sugita

      ADVANCES IN SPACE RESEARCH60 ( 7 ) 1453 - 1462   10 2017

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

      Mass spectrometry has been widely used in lander missions to characterize the volatiles in rocks and soils on planetary surfaces. A good vacuum seal is very important for introducing such solid samples to a vacuum chamber and ejecting them. However, multiple measurements require many metal gaskets, leading to extra weight and complexity for the instruments. In this study, we investigate the capability of three kinds of elastomeric O-rings (Viton, Nexus-SLT, and Nexus-FV) as vacuum seals for mass spectrometric measurements, particularly for in situ K-Ar dating on Mars. First, thermal cycle tests revealed that low-temperature-resistant O-rings can maintain pressure &lt; 10(-5) Pa at -60 degrees C under 1 bar ambient pressure, whereas Viton O-rings leaked at -25 degrees C. Then, the amount of Ar-40 due to out gassing from the O-rings and permeation under the ambient pressure of 650 Pa or 3 Pa was measured and compared with the amounts of Ar-40 that a flight-equivalent laser would liberate from potential target Martian rocks. The measured amounts were &lt; 1% of that a target rock with 5000 ppm K2O and an age of 4.2 Ga would yield. These results suggest that a Viton O-ring can maintain the AT blank low under the Mars atmospheric pressure when temperatures are higher than -25 degrees C. A double O-ring seal using the low-temperature resistant elastomers would be an alternative approach at lower temperatures. The elastomeric O-rings would be useful for constructing a small and light-weighted mass spectrometric instrument for in situ K-Ar dating on Mars. (C) 2017 COSPAR. Published by Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.asr.2017.07.002

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    • Preflight Calibration Test Results for Optical Navigation Camera Telescope (ONC-T) Onboard the Hayabusa2 Spacecraft Peer-reviewed

      S. Kameda, H. Suzuki, T. Takamatsu, Y. Cho, T. Yasuda, M. Yamada, H. Sawada, R. Honda, T. Morota, C. Honda, M. Sato, Y. Okumura, K. Shibasaki, S. Ikezawa, S. Sugita

      SPACE SCIENCE REVIEWS208 ( 1-4 ) 17 - 31   7 2017

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER  

      The optical navigation camera telescope (ONC-T) is a telescopic framing camera with seven colors onboard the Hayabusa2 spacecraft launched on December 3, 2014. The main objectives of this instrument are to optically navigate the spacecraft to asteroid Ryugu and to conduct multi-band mapping the asteroid. We conducted performance tests of the instrument before its installation on the spacecraft. We evaluated the dark current and bias level, obtained data on the dependency of the dark current on the temperature of the charge-coupled device (CCD). The bias level depends strongly on the temperature of the electronics package but only weakly on the CCD temperature. The dark-reference data, which is obtained simultaneously with observation data, can be used for estimation of the dark current and bias level. A long front hood is used for ONC-T to reduce the stray light at the expense of flatness in the peripheral area of the field of view (FOV). The central area in FOV has a flat sensitivity, and the limb darkening has been measured with an integrating sphere. The ONC-T has a wheel with seven bandpass filters and a panchromatic glass window. We measured the spectral sensitivity using an integrating sphere and obtained the sensitivity of all the pixels. We also measured the point-spread function using a star simulator. Measurement results indicate that the full width at half maximum is less than two pixels for all the bandpass filters and in the temperature range expected in the mission phase except for short periods of time during touchdowns.

      DOI: 10.1007/s11214-015-0227-y

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    • IMAGING OBSERVATIONS OF THE HYDROGEN COMA OF COMET 67P/CHURYUMOV-GERASIMENKO IN 2015 SEPTEMBER BY THE PROCYON/LAICA Peer-reviewed

      Yoshiharu Shinnaka, Nicolas Fougere, Hideyo Kawakita, Shingo Kameda, Michael R. Combi, Shota Ikezawa, Ayana Seki, Masaki Kuwabara, Masaki Sato, Makoto Taguchi, Ichiro Yoshikawa

      ASTRONOMICAL JOURNAL153 ( 2 )   2 2017

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

      The water production rate of a comet is one of the. fundamental parameters necessary. to understand cometary activity when a comet approaches the Sun within 2.5 au, because water is the most abundant icy material in the cometary nucleus. Wide-field imaging observations of the hydrogen Ly alpha emission in comet 67P/Churyumov-Gerasimenko were performed by the Lyman Alpha Imaging Camera (LAICA) on. board the 50 kg class micro spacecraft, the Proximate Object Close Flyby with Optical Navigation (PROCYON), on UT 2015 September 7.40, 12.37, and 13.17 (corresponding to 25.31, 30.28, and 31.08 days after the perihelion passage of the comet, respectively). We derive the water production rates, QH(2)O, of the comet from Lya images of the comet by using a 2D axi-symmetric Direct Simulation Monte-Carlo model of the atomic hydrogen coma; (1.46. +/- 0.47) x 10(28), (1.24. +/- 0.40) x10(28), and (1.30. +/- 0.42) x 10(28) molecules s(-1) on 7.40, 12.37, and 13.17 September, respectively. These values are comparable to the values from in situ measurements by the Rosetta instruments in the 2015 apparition and the ground-based and space observations during the past apparitions. The comet did not show significant secular change in average water production rates just after the perihelion passage for the apparitions from 1982 to 2015. We emphasize that the measurements of absolute QH(2)O based on the wide field of view (e. g., by the LAICA/PROCYON) are so important to judge the soundness of the coma models used to infer QH(2)O based on in situ measurements by spacecraft, like the Rosetta.

      DOI: 10.3847/1538-3881/153/2/76

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    • An in-situ K-Ar isochron dating method for planetary landers using a spot-by-spot laser-ablation technique Peer-reviewed

      Yuichiro Cho, Seiji Sugita, Yayoi N. Miura, Ryuji Okazaki, Naoyoshi Iwata, Tomokatsu Morota, Shingo Kameda

      PLANETARY AND SPACE SCIENCE128   14 - 29   9 2016

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      Age is essential information for interpreting the geologic record on planetary surfaces. Although crater counting has been widely used to estimate the planetary surface ages, crater chronology in the inner solar system is largely built on radiometric age data from limited sites on the Moon. This has resulted in major uncertainty in planetary chronology. Because opportunities for sample-return missions are limited, in-situ geochronology measurements from one-way lander/rover missions are extremely valuable. Here we developed an in-situ isochron-based dating method using the K-Ar system, with K and Ar in a single rock sample extracted locally by laser ablation and measured using laser-induced breakdown spectroscopy (LIBS) and a quadrupole mass spectrometer (QMS), respectively. We built an experimental system combining flight equivalent instruments and measured K-Ar ages for mineral samples with known ages (similar to 1.8 Ga) and K contents (1-8 wt%); we achieved precision of 20% except for a mineral with low mechanical strength. Furthermore, validation measurements with two natural rocks (gneiss slabs) obtained K-Ar isochron ages and initial Ar-40 consistent with known values for both cases. This result supports that our LIBS-MS approach can derive both isochron ages and contributions of non-in situ radiogenic Ar-40 from natural rocks. Error assessments suggest that the absolute ages of key geologic events including the Noachian/Hesperian- and the Hesperian/Amazonian-transition can be dated with 10-20% errors for a rock containing similar to 1 wt% K2O, greatly reducing the uncertainty of current crater chronology models on Mars. (C) 2016 Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.pss.2016.05.004

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    • Quantitative Potassium Measurements with Laser-Induced Breakdown Spectroscopy Using Low-Energy Lasers: Application to In Situ K-Ar Geochronology for Planetary Exploration Peer-reviewed

      Cho Y, Horiuchi M, Shibasaki K, Kameda S, Sugita S

      Applied Spectroscopy   8 2016

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    • Conceptual Design of an In Situ K-Ar Isochron Dating Instrument for Future Mars Rover Missions, Transactions of the Japan Society for Aeronautical and Space Sciences Peer-reviewed

      Cho, Y, Kameda, S, Miura, Y, Saito, Y, Yokota, S, Kasahara, S, Okazaki, R, Yoshioka, K, Shibasaki, K, Oishi, T, Sugita, S

      Aerospace Technology Japan 2016.14   89 - 94   2016

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    • Detectability of hydrous minerals using ONC-T camera onboard the Hayabusa2 spacecraft Peer-reviewed

      S. Kameda, H. Suzuki, Y. Cho, S. Koga, M. Yamada, T. Nakamura, T. Hiroi, H. Sawada, R. Honda, T. Morota, C. Honda, A. Takei, T. Takamatsu, Y. Okumura, M. Sato, T. Yasuda, K. Shibasaki, S. Ikezawa, S. Sugita

      ADVANCES IN SPACE RESEARCH56 ( 7 ) 1519 - 1524   10 2015

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      The Hayabusa2 spacecraft has three framing cameras (ONC-T, ONC-W1, and ONC-W2) for optical navigation to asteroid 1999 JU(3). The ONC-T is a telescopic camera with seven band-pass filters in the visible and near-infrared range. These filters are placed on a wheel, which rotates to put a selected filter for different observations, enabling multiband imaging. Previous ground-based observations suggesting that hydrous materials may be present on the surface of 1999 JU(3) and distributed in relatively limited areas. The presence of hydrous minerals indicates that this asteroid experienced only low to moderate temperatures during its formation, suggesting that primordial materials are preserved. In order to find the best sampling sites, we will perform reflectance spectroscopic observations using the ONC-T near the asteroid after arrival. Finding regions rich in hydrous minerals is the key for this remote sensing observation. In preparation for this, we conducted ground-based experiments for the actual ONC-T flight model to confirm the detectability of the absorption band of Fe-rich serpentine. As a result, we detected the absorption band near 0.7 mu m by reflectance spectroscopy of CM2 chondrites, such as Murchison and Nogoya, which are known to contain the Fe-rich serpentine, and did not detect any 0.7 mu m absorption in Jbilet Winselwan CM2 chondrite with decomposed Fe-rich serpentine. (C) 2015 COSPAR. Published by Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.asr.2015.06.037

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    • High-precision potassium measurements using laser-induced breakdown spectroscopy under high vacuum conditions for in situ K-Ar dating of planetary surfaces Peer-reviewed

      Cho Yuichiro, Sugita Seiji, Kameda Shingo, Miura Yayoi N, Ishibashi Ko, Ohno Sohsuke, Kamata Shunichi, Arai Tomoko, Morota Tomokatst, Namiki Noriyuki, Matsui Takafumi

      SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY106   28 - 35   1 4 2015

    • Plasmaspheric filament: An isolated magnetic flux tube filled with dense plasmas Peer-reviewed

      Go Murakami, Ichiro Yoshikawa, Kazuo Yoshioka, Atsushi Yamazaki, Masato Kagitani, Makoto Taguchi, Masayuki Kikuchi, Shingo Kameda, Masato Nakamura

      Geophysical Research Letters40 ( 2 ) 250 - 254   28 1 2013

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      The Telescope of Extreme Ultraviolet (TEX) onboard Japan's lunar orbiter KAGUYA provided the first sequential images of the Earth's plasmasphere from the "side" (meridian) view. The TEX instrument obtained the global distribution of the terrestrial helium ions (He+) by detecting resonantly scattered emission at 30.4 nm. One of the most striking features of the plasmasphere found by TEX is an arc-shaped structure of enhanced brightness, which we call a "plasmaspheric filament". In the TEX image on 2 June 2008, the filament structure was clearly aligned to the dipole magnetic field line of L = 3.7 at 7.3 magnetic local time. Our analysis suggests that the filament represents an isolated flux tube filled with four times higher He + density than its neighbors. We found four events of plasmaspheric filament in the images obtained between March and June 2008, and in all four events, the geomagnetic activity was quite low. The plasmaspheric filament in the TEX image is the first evidence that a "finger" structure seen in the IMAGE-EUV image is the projection of an isolated flux tube. © 2013. American Geophysical Union. All Rights Reserved.

      DOI: 10.1002/grl.50124

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    • Image of the Cold Plasmas around the Earth Observed by Telescope of Extreme Ultraviolet (TEX) onboard KAGUYA: Geoscience from the Moon Peer-reviewed

      Murakami, Go, Yoshikawa, Ichiro, Yamazaki, Atsushi, Yoshioka, Kazuo, Kameda, Shingo, Miyake, Wataru, Taguchi, Makoto, Kikuchi, Masayuki, Nakamura, Masato, Okano, Shoichi

      Transactions of the Japanese Society for Artificial Intelligence   12 2012

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    • はやぶさ2搭載の Optical Navigation Camera (ONC) による科学観測

      杉田 精司, 本田 理恵, 亀田 真吾, 諸田 智克, 澤田 弘崇, 本田 親寿, 鈴木 秀彦, 小川 和律, 飯島 祐一, 白井 慶, 中村 良介, 山田 学, ONC サイエンスチーム

      宇宙科学技術連合講演会講演集56   2012

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    • The EXCEED mission Peer-reviewed

      Yoshikawa I, Yoshioka K, Murakami G, Ogawa G, Ueno M, Yamazaki A, Uemizu K, Kameda S, Tsuchiya F, Kagitani M, Terada N, Kasaba Y

      Advances in Geosciences: Volume 25: Planetary Science (PS)   29 - 41   2011

    • Variation in lunar sodium exosphere measured from lunar orbiter SELENE (Kaguya) Peer-reviewed

      M. Kagitani, M. Taguchi, A. Yamazaki, I. Yoshikawa, G. Murakami, K. Yoshioka, S. Kameda, S. Okano

      PLANETARY AND SPACE SCIENCE58 ( 12 ) 1660 - 1664   10 2010

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

      Resonant scattering of the lunar sodium exosphere was measured from the lunar orbiter SELENE (Kaguya) from December 2008 to June 2009. Variations in line-of-sight integrated intensity measured on the night-side hemisphere of the Moon could be described as a spherical symmetric distribution of the sodium exosphere with a temperature of 2400-6000 K. Average surface density of sodium atoms in February is well above that in the other months by about 30%. A clear variation in surface density related to the Moon&apos;s passage across the Earth&apos;s magnetotail could not be seen, although sodium density gradually decreased (by 20 +/- 8%) during periods from the first through the last quarter of two lunar cycles. These results suggest that the supra-thermal components of the sodium exosphere are not mainly produced by classical sputtering of solar wind. The variation in sodium density (which depends on lunar-phase angle) is possibly explained by the presence of an inhomogeneous source distribution of photon-stimulated desorption (PSD) on the surface. (c) 2010 Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.pss.2010.07.025

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    • Plasmaspheric EUV images seen from lunar orbit: Initial results of the extreme ultraviolet telescope on board the Kaguya spacecraft Peer-reviewed

      Yoshikawa, I, Murakami, G, Ogawa, G, Yoshioka, K, Obana, Y, Taguchi, M, Yamazaki, A, Kameda, S, Nakamura, M, Kikuchi, M, Kagitani, M, Okano, S, Miyake, W

      Journal of Geophysical Research   27 8 2010

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    • Extreme ultraviolet spectroscope for exospheric dynamics explore (exceed) Peer-reviewed

      Ichiro Yoshikawa, Kazuo Yoshioka, Go Murakami, Atsushi Yamazaki, Shingo Kameda, Munetaka Ueno, Naoki Terada, Fuminori Tsuchiya, Masato Kagitani, Yasumasa Kasaba

      Advances in Geosciences: Volume 19: Planetary Science (PS)   579 - 592   1 2010

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      © 2010 by World Scientific Publishing Co. Pte. Ltd. All rights reserved. An earth-orbiting Extreme Ultraviolet spectroscopic mission, EXtreme ultraviolet spectrosCope for ExosphEric Dynamics explore (EXCEED) that will be launched in 2012 is now under development. The EXCEED mission will carry out observations of Extreme Ultraviolet (EUV) emissions from tenuous plasmas around the planets. It is essential for planetary EUV spectroscopy to avoid the Earth’s atmospheric absorption, therefore it should be mandatory to observe above the Earth’s atmosphere. In this paper, we will introduce the general mission overview, the instrument, and the scientific targets.

      DOI: 10.1142/9789812838162_0043

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    • The BepiColombo mission: An outstanding tool for investigating the Hermean environment Peer-reviewed

      A. Milillo, M. Fujimoto, E. Kallio, S. Kameda, F. Leblanc, Y. Narita, G. Cremonese, H. Laakso, M. Laurenza, S. Massetti, S. McKenna-Lawlor, A. Mura, R. Nakamura, Y. Omura, D. A. Rothery, K. Seki, M. Storini, P. Wurz, W. Baumjohann, E. J. Bunce, Y. Kasaba, J. Helbert, A. Sprague

      PLANETARY AND SPACE SCIENCE58 ( 1-2 ) 40 - 60   1 2010

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      Mercury possesses a weak, internal, global magnetic field that supports a small magnetosphere populated by charged particles originating from the solar wind, the planet's exosphere and surface layers. Mercury's exosphere is continuously refilled and eroded through a variety of chemical and physical processes acting in the planet's surface and environment. Using simultaneous two-point measurements from two satellites, ESA's future mission BepiColombo will offer an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with solar radiation and interplanetary dust. The expected data will provide important insights into the evolution of a planet in close proximity of a star. Many payload instruments aboard the two spacecraft making up the mission will be completely, or partially, devoted to studying the close environment of the planet as well as the complex processes that govern it. Coordinated measurements by different onboard instruments will permit a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone. Thus, an important feature of the BepiColombo mission is that simultaneous two-point measurements can be implemented at a location in space other than the Earth. These joint observations are of key importance because many phenomena in Mercury's environment are temporarily and spatially varying. In the present paper, we focus on some of the exciting scientific goals achievable during the BepiColombo mission through making coordinated observations. (C) 2008 Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.pss.2008.06.005

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    • The Mercury sodium atmospheric spectral imager for the MMO spacecraft of Bepi-Colombo Peer-reviewed

      I. Yoshikawa, O. Korablev, S. Kameda, D. Rees, H. Nozawa, S. Okano, V. Gnedykh, V. Kottsov, K. Yoshioka, G. Murakami, F. Ezawa, G. Cremonese

      PLANETARY AND SPACE SCIENCE58 ( 1-2 ) 224 - 237   1 2010

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

      The Mercury Sodium Atmosphere Spectral Imager (MSASI) on the Mercury Magnetospheric Orbiter (MMO) of the JAXA/ESA Bepi-Colombo (BC) Mission will address a range of fundamental scientific questions pertaining to Mercury&apos;s exosphere. The measurements will provide new information on regolith-exosphere-magnetosphere coupling as well as new understanding of the dynamics governing the exosphere bounded by the planetary surface, the solar wind and interplanetary space. MSASI is a high-dispersion visible spectrometer working in the spectral region near the sodium D(2) emission (589 nm), a major constituent of the Mercury exosphere. A single high-resolution Fabry-Perot etalon is used in combination with a narrow-band interference filter to achieve a compact and efficient instrument design. The etalon and filter are extremely stable with respect to long-term aging and temperature variations. Full-disk images of the planet are obtained by means of a single-axis scanning mirror in combination with the spin of the MMO spacecraft. This paper presents an overview of the MSASI and the design of the Fabry-Perot interferometer used as its spectral analyser.
      It is concluded that:
      (1) The MSASI optical design is practical and can be implemented without new or critical technology developments.
      (2) The thermally stable etalon design is based on concepts, designs and materials that have a good space heritage.
      (3) The MSASI instrument will achieve a high signal-to-noise ratio (SNR) (&gt; 10) in the range of 2K-10M Rayleigh. (C) 2008 Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.pss.2008.07.008

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    • First sequential images of the plasmasphere from the meridian perspective observed by KAGUYA Peer-reviewed

      Go Murakami, Ichiro Yoshikawa, Yuki Obana, Kazuo Yoshioka, Gentaro Ogawa, Atsushi Yamazaki, Masato Kagitani, Makoto Taguchi, Masayuki Kikuchi, Shingo Kameda, Masato Nakamura

      EARTH PLANETS AND SPACE62 ( 4 ) E9 - E12   2010

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:TERRA SCIENTIFIC PUBL CO  

      Our understanding of plasmaspheric dynamics has increased in recent years largely due to the information generated during the IMAGE-EUV mission. Even though this successful mission has ended, we have succeeded in imaging the terrestrial helium ions (He(+)) by the Telescope of Extreme Ultraviolet (TEX) aboard the Japanese lunar orbiter KAGUYA by detecting resonantly scattered emission at 30.4 nm. The view afforded by the KAGUYA orbit encompasses the plasma (He(+)) distribution in a single exposure, enabling us to examine for the first time the globally averaged properties of the plasmasphere from the "side" (meridian) perspective. The TEX instrument observed a medium-scale density structure in the dawnside plasmasphere during a quiet period (1-2 June 2008). The meridian shape of the structure clearly agreed with the dipole magnetic field line. The TEX instrument also observed the structure in the plasmasphere co-rotating with a duration of 26 h, which is consistent with results from a number of recent studies derived from the IMAGE-EUV mission. These results confirm that the TEX instrument successfully obtained the spatial distribution and temporal variation of the plasmasphere.

      DOI: 10.5047/eps.2010.02.006

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    • Observation of the Near-Earth Plasmas by Telescope of Extreme Ultraviolet (TEX) Onboard SELENE: Science from the Moon Peer-reviewed

      Yoshikawa, I, Yamazaki, A, Murakami, G, Ezawa, F, Yoshioka, K, Kameda, S, Miyake, W, Taguchi, M, Kikuchi, M, Nakamura, M, Sakanoi, T, Okano, T

      Transactions of the Japan society for aeronautical and space sciences, space technology Japan7   27 - 32   2010

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      DOI: 10.2322/tstj.7.Tk_27

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    • Telescope of Extreme Ultraviolet boarded on KAGUYA: Science from the Moon Peer-reviewed

      Yoshikawa, I, Murakami, G, Ezawa, F, Yoshioka, K, Obana, Y, Taguchi, M, Yamazaki, A, Kameda, S, Nakamura, M, Kikuchi, M, Kagitani, M, Okano, S, Shiokawa, K, Miyake, W

      Advances in Geosciences19   109 - 121   2010

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      DOI: 10.1142/9789812838162_0009

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    • Interplanetary dust distribution and temporal variability of Mercury&apos;s atmospheric Na Peer-reviewed

      Shingo Kameda, Ichiro Yoshikawa, Masato Kagitani, Shoichi Okano

      GEOPHYSICAL RESEARCH LETTERS36   8 2009

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER GEOPHYSICAL UNION  

      The interplanetary dust (IPD) distribution in the inner solar system is not yet well understood because of lack of direct dust measurements in the inner solar system and so one needs to rely on zodiacal light observations that are difficult to interpret. Mercury has an unstable atmosphere, and the source processes of Na in its atmosphere are unclear. Results of past observations have revealed that the atmospheric Na density has no or low correlation with the solar flux, sunspot number, heliocentric distance, or solar radiation pressure. We show that the variability of Mercury&apos;s atmospheric Na density depends strongly on the IPD distribution. That is, Na density is low (high) when Mercury is far away from (close to) the symmetry plane of IPD, and so one can infer the IPD distribution near Mercury orbit from the temporal variability of Na density in Mercury&apos;s atmosphere. Citation: Kameda, S., I. Yoshikawa, M. Kagitani, and S. Okano (2009), Interplanetary dust distribution and temporal variability of Mercury&apos;s atmospheric Na, Geophys. Res. Lett., 36, L15201, doi:10.1029/2009GL039036.

      DOI: 10.1029/2009GL039036

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    • First optical observation of the Moon&apos;s sodium exosphere from the lunar orbiter SELENE (Kaguya) Peer-reviewed

      M. Kagitani, M. Taguchi, A. Yamazaki, I. Yoshikawa, G. Murakami, K. Yoshioka, S. Kameda, F. Ezawa, T. Toyota, S. Okano

      EARTH PLANETS AND SPACE61 ( 8 ) 1025 - 1029   2009

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      The first successful observations of resonant scattering emission from the lunar sodium exosphere were made from the lunar orbiter SELENE (Kaguya) using TVIS instruments during the period 17-19 December, 2008. The emission intensity of the NaD-line decreased by 12 +/- 6%, with an average value of 5.4 kR (kilorayleighs) in this period, which was preceded, by I day, by enhancement of the solar proton flux associated with a corotating interaction region. The results suggest that solar wind particles foster the diffusion of sodium atoms or ions in the lunar regolith up to the surface and that the time scale of the diffusion is a few tens of hours. The declining activity of the Geminid meteor shower is also one possible explanation for the decreasing sodium exosphere.

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    • Observation of the lunar sodium exposure using UPI-TVIS onboard SELENE (Kaguya) Peer-reviewed

      M. Kagitani, M. Taguchi, A. Yamazaki, I. Yoshikawa, G. Murakami, K. Yoshioka, S. Kameda, F. Ezawa, T. Toyota, S. Okano

      Earth Planet. Space61 ( 1-5 )   2009

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    • The Upper Atmosphere and Plasma Imager/the Telescope of Visible Light (UPI/TVIS) onboard the Kaguya spacecraft Peer-reviewed

      M. Taguchi, T. Sakanoi, S. Okano, M. Kagitani, M. Kikuchi, M. Ejiri, I. Yoshikawa, A. Yamazaki, G. Murakami, K. Yoshioka, S. Kameda, W. Miyake, M. Nakamura, K. Shiokawa

      EARTH PLANETS AND SPACE61 ( 12 ) XVII - XXIII   2009

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:TERRA SCIENTIFIC PUBL CO  

      The Upper Atmosphere and Plasma Imager (UPI) was placed in a lunar orbit in order to Study both the Moon and Earth. The UPI consists of two telescopes: a Telescope of Extreme Ultraviolet (TEX) and a Telescope of Visible Light (TVIS), which are both mounted on a two-axis gimbals system. The TVIS is equipped with fast catadioptric optics and a high-sensitivity CCD to image swift aurora and dark airglow ill the terrestrial upper atmosphere. TVIS has a field-of-view equivalent to the Earth&apos;s disk as seen from the Moon. The spatial resolution is about 30 km x 70 km on the Earth&apos;s surface at auroral latitudes. The observation wavelengths can be changed by selecting different bandpass filters. Using the images of the northern and Southern auroral ovals taken by TVIS, the intensities and shapes of the conjugate auroras will be quantitatively compared. Using the an-low imaging, medium- and large-scale ionospheric disturbances will be Studied. In this paper, the instrumental design and performance of TVIS are presented.

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    • Observation of Mercury's sodium exosphere during the transit on November 9, 2006 Peer-reviewed

      Ichiro Yoshikawa, Junya Ono, Kazuo Yoshioka, Go Murakami, Fukuhiro Ezawa, Shingo Kameda, Satoru Ueno

      PLANETARY AND SPACE SCIENCE56 ( 13 ) 1676 - 1680   11 2008

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

      A rare, but normal, astronomical event occurred on November 9th 2006 (JST) as Mercury passed in front of the Sun from the perspective of the Earth. The abundance of the sodium vapor above the planet limb was observed by detecting an excess absorption in the solar sodium line D, during this event. The observation was performed with a 10-m spectrograph of Czerny-Turnar system at Domeless Solar Tower Telescope at the Hida Observatory in Japan. The excess absorption was red-shifted by 10 pm relative to the solar line, and was measured at the dawnside (eastside) and duskside (westside) of Mercury. Between the dawn and dusksides, an asymmetry of total sodium abundance was clearly identified. At the dawnside, the total sodium column density was 6.1 x 10(10) Na atoms/cm(2), while it was 4.1 x 10(10) Na atoms/cm(2) at the duskside. The investigation of dawn-dusk asymmetry of the sodium exosphere of Mercury is a clue to understand the release mechanism of sodium from the surface rock. Our result suggests that a thermal desorption is a main source process for sodium vapor in the vicinity of Mercury. (C) 2008 Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.pss.2008.07.026

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    • Attempt to identify a source mechanism of Mercury's sodium exosphere by a spectrometer using Fabry-Perot etalon Peer-reviewed

      I. Yoshikawa, S. Kameda, K. Hikosaka, G. Murakami, D. Rees, H. Nozawa, S. Okano, O. Korablev

      ADVANCES IN SPACE RESEARCH42 ( 7 ) 1172 - 1179   10 2008

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

      The Mercury's Sodium Atmosphere Spectral Imager (MSASI) on BepiColombo (BC) will address a range of fundamental scientific questions pertaining to Mercury's exosphere. The measurements will provide new information on regolith-exosphere-magnetosphere coupling as well as new understanding of the dynamics governing the exosphere bounded by the planetary surface, the solar wind and interplanetary space. MSASI is a high-dispersion visible spectrometer working in the spectral range around sodium D2 emission (589 nm). A tandem Fabry-Perot etalon is used to achieve a compact design. We presents a design of the spectral analyzer using Fabry-Perot interferometer. We conclude that: (1) The MSASI optical design is practical and can be implemented without new or critical technology developments; (2) The thermally-tuned etalon design is based on concepts, designs and materials that have good space heritage. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.asr.2007.09.018

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    • Mercury's sodium exosphere explored by the BepiColombo mission Peer-reviewed

      K. Yoshioka, K. Hikosaka, S. Kameda, H. Nozawa, A. Yamazaki, I. Yoshikawa

      ADVANCES IN SPACE RESEARCH41 ( 9 ) 1386 - 1391   2008

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

      The Mercury's Sodium Atmosphere Spectral Imager (MSASI) on BepiColombo will address fundamental scientific questions pertaining to the Mercury's sodium exosphere. Together, our measurements on the overall scale will provide ample new information on regolith-exosphere-magnetosphere coupling as well as new understanding of the dynamics governing the surface-bounded exosphere. We will compare the four different source mechanisms in preparation for modeling MSASI data and show the feasibility of identifying a process. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.asr.2007.11.024

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    • Observation of Mercury's sodium tail using Fabry-Perot interferometer Peer-reviewed

      S. Kameda, M. Kagitani, S. Okano, I. Yoshikawa, J. Ono

      ADVANCES IN SPACE RESEARCH41 ( 9 ) 1381 - 1385   2008

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

      We observed sodium emission from Mercury's atmosphere using a Fabry-Perot Interferometer at Haleakala Observatory on June 14, 2006. The Fabry-Perot Interferometer was used as a wavelength-tunable filter. The spectra of the surface reflection were subtracted from the observed spectra because sodium emission is contaminated by the surface reflection of Mercury. The image obtained in our observation shows the sodium exosphere extended to the anti-solar direction. The lifetime of a sodium atom was estimated to be 1.6 x 10(4) to 1.9 X 10(5) s with an error by a factor of 3-4. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.asr.2007.09.039

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    • Telescope of extreme ultraviolet (TEX) onboard SELENE: science from the Moon Peer-reviewed

      I. Yoshikawa, A. Yamazaki, G. Murakami, K. Yoshioka, S. Kameda, F. Ezawa, T. Toyota, W. Miyake, M. Taguchi, M. Kikuchi, M. Nakamura

      EARTH PLANETS AND SPACE60 ( 4 ) 407 - 416   2008

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:TERRA SCIENTIFIC PUBL CO  

      The Upper Atmosphere and Plasma Imager (UPI) is to be launched in 2007 and sent to the Moon. From the lunar orbit, two telescopes are to be directed towards the Earth. The Moon has no atmosphere, which results in there being no active emission near the spacecraft; consequently, we will have a high-quality image of the near-Earth environment. As the Moon orbits the Earth once a month, the Earth will also be observed from many different directions. This is called a "science from the Moon". The two telescopes are mounted on a two-axis gimbal system, the Telescope of Extreme ultraviolet (TEX) and Telescope of Visible light (TVIS). TEX detects the O II (83.4 nm) and He II (30.4 nm) emissions scattered by ionized oxygen and helium, respectively. The targets of extreme-ultraviolet (EUV) imaging are the polar ionosphere, the polar wind, and the plasmasphere and inner magnetosphere. The maximum spatial and time resolutions are 0.09 Re and 1 min, respectively.

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    • Observation of Mercury's sodium exosphere by MSASI in the BepiColombo mission Peer-reviewed

      I. Yoshikawa, S. Kameda, K. Matsuura, K. Hikosaka, G. Murakami, K. Yoshioka, H. Nozawa, D. Rees, S. Okano, H. Misawa, A. Yamazaki, O. Korablev

      PLANETARY AND SPACE SCIENCE55 ( 11 ) 1622 - 1633   9 2007

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

      The Mercury's sodium atmosphere spectral imager (MSASI) on BepiColombo (BC) will address a range of fundamental scientific questions pertaining to Mercury's exosphere. The measurements will provide new information on regolith-exosphere-magnetosphere coupling as well as new understanding of the dynamics governing the exosphere bounded by the planetary surface, the solar wind and interplanetary space. MSASI is a high-dispersion visible spectrometer working in the spectral range around sodium D2 emission (589 nm). A tandem Fabry-Perot etalon is used to achieve a compact design. A one-degree-of-freedom scanning mirror is employed to obtain full-disk images of the planet. This paper presents an overview of the MSASI and the design of its spectral analyzer, which uses a Fabry-Perot interferometer. We conclude that: (1) The MSASI optical design is practical and can be implemented without new or critical technology developments. (2) The thermally tuned etalon design is based on concepts, designs and materials that have good space heritage. (3) The MSASI instrument achieves a high SNR (&gt; 10) in the range of 2k-10 MRayleigh. (C) 2007 Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.pss.2006.01.010

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    • Time variation in exospheric sodium density on Mercury Peer-reviewed

      S. Kameda, I. Yoshikawa, J. Ono, H. Nozawa

      PLANETARY AND SPACE SCIENCE55 ( 11 ) 1509 - 1517   9 2007

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

      We conducted continuous spectroscopic observations of the Mercury's sodium exosphere with a 188 cm telescope and a high dispersion echelle spectrograph, for 1-6h in the daytime on December 4, 13, 14, and 15, 2005. To correct the images of the sodium emission blurred by Earth's atmosphere, the observed distribution was deconvolved with the point spread function which was obtained using Hapke's surface reflection model and the observed surface reflection. The average column density of sodium atoms was 1-2 x 10(11) atoms/cm(2) and significant diurnal changes were not observed. However, the sodium densities at low latitudes and high latitude changed during the observation and the rate of change in density at low latitude was higher than that at high latitude on December 14 and 15. Although the rates of suggested release processes are higher than the observed rate, the suggested release processes cannot explain the rapid change in density at low latitude. This may suggest the effect of transport of neutral atoms and the recycling of ions to the surface dominates the time variation in the spatial distribution of exospheric sodium atoms on Mercury. (C) 2007 Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.pss.2006.10.010

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    • Study of time variation in exospheric sodium density on Mercury

      Shingo Kameda

          22 3 2007

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      Language:English   Publishing type:Doctoral thesis  

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    • Attempt to identify a source mechanism of Mercury's sodium exosphere by remote-sensing technique

      Yoshikawa, I, Hikosaka, K, Kameda, S, Okano, S, Nozawa, H, Yamazaki, A, Korablev, O, Rees, D

      36th COSPAR Scientific Assembly. Held 16 - 23 July 2004, in Beijing, China   1333   7 2006

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    • Ground-based observations of sodium in Mercuryüfs exosphere

      Kameda, S, Kagitani, M, Ono, J, Nozawa, H, Yoshikawa, I, Okano, S

      36th COSPAR Scientific Assembly. Held 16 - 23 July 2004, in Beijing, China   2384   7 2006

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    • 水星大気の生成メカニズムに関する研究 ~MMO搭載機器MSASIでの観測に向けて~ Peer-reviewed

      吉岡和夫彦坂健太郎, 亀田真吾, 野澤宏大, 吉岡和夫, 山崎敦, 吉川一朗, 笠羽康正

      宇宙航空研究開発機構研究開発報告JAXA-RR-05-021 ( 1 ) 16   2006

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    • Observation of the sodium exosphere from mercury magnetospheric orbiter Peer-reviewed

      Ichiro Yoshikawa, Hiromasa Nozawa, Shingo Kameda, Shoichi Okano, Hiroaki Misawa

      ADVANCES IN SPACE RESEARCH38 ( 4 ) 659 - 663   2006

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

      The Mercury Sodium Atmosphere Spectral Imager (MSASI) in the BepiColombo mission will address a wealth of fundamental scientific questions pertaining to the Mercury's exosphere. Together, our measurements on the overall scale will provide ample new information on regolith-exosphere-magnetosphere coupling as well as new understanding of the dynamics governing the 'surface-bounded exosphere'.
      It arises quite clearly from ground-based observations that the regolith of Mercury releases a fraction of its content to the exosphere. Some processes are identified up to now as leading to this ejection, e.g., photon-stimulated desorption. These processes are associated with different energies of ejection and behaviors in different regions of Mercury's surface. Therefore, different types of population are born from the surface, depending on the processes. The MSASI measurements definitely can identify the release processes, how exospheric sodium is born from the regolith. MSASI/BepiColombo is the first and unique opportunity to study the formation, circulation, and maintenance of the surface-bounded exosphere. (c) 2006 COSPAR. Published by Elsevier Ltd. All rights reserved.

      DOI: 10.1016/j.asr.2005.05.134

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    • Mercury Sodium Atmosphere Spectral Imager (MSASI) Peer-reviewed

      Nozawa, H, I. Yoshikawa, S. Kameda, H. Misawa, S. Okano, M. Taguchi, A. Yamazaki, Y. Kasaba, K. Takamizawa, O. Korablev

      JAXA Research and Development Report   JAXA-RR-05-007E   2005

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    • Development of an extreme ultraviolet imaging spectrometer for the BepiColombo mission Peer-reviewed

      Yoshikawa, I, A Yamazaki, T Murachi, S Kameda, H Sagawa, S Okano, T Okada, M Nakamura

      MERCURY, MARS AND SATURN33 ( 12 ) 2195 - 2199   2004

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      Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

      Extreme and far ultraviolet imaging spectrometers are proposed for the low-altitude orbiter of the BepiColombo mission. The UV instrument, consisting of the two spectrometers with common electronics, aims at measuring (1) emission lines from molecules, atoms and ions present in the Mercury's tenuous atmosphere and (2) the reflectance spectrum of Mercury's surface. The instrument pursues a complete coverage in UV spectroscopy. The extreme UV spectrometer covers the spectral range of 30-150 nm with the field of view of 5.0degrees, and the spectrum from 130 to 430 nm is obtained by the far UV spectrometer. The extreme UV spectrometer employs multi-layer coating technology to enhance its sensitivity at particular emission lines. This technology enables us to identify small ionospheric signatures such as He II (30.4 nm) and Na II (37.2 nm), which could not be detected with conventional optics. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

      DOI: 10.1016/s0273-1177(03)00446-0

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    • Development of an extreme ultraviolet imaging spectrometer for the mercury mission Peer-reviewed

      Yoshikawa I, Murachi T, Kameda S, Yamazaki A, Okano S, Nakamura M

      ADVANCES IN MIRROR TECHNOLOGY FOR X-RAY, EUV LITHOGRAPHY, LASER, AND OTHER APPLICATIONS5193   164 - 171   2004

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    • Development of multilayer gratings for spectroscopy of Mercury's atmosphere Peer-reviewed

      Kameda, S, Sagawa, H, Murachi, T, Yamazaki, A, Yoshikawa, I, Nakamura, M

      ISAS Report ( 124 ) 1 - 14   9 2003

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      Language:Japanese   Publishing type:Research paper (bulletin of university, research institution)  

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    Misc.

    • 一番星へ行こう!日本の金星探査機の挑戦その30 〜1 umカメラで金星昼&夜〜

      岩上直幹, はしもとじょーじ, 澤井健太, 坂野井健, 高木聖子, 亀田真吾

      日本惑星科学会誌「遊星人」26 ( 1 ) 21 - 22   2017

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    • 地球外気圏に関する観測的研究

      桑原正輝, 吉岡和夫, 村上豪, 土屋史紀, 木村智樹, 亀田真吾, 佐藤允基, 吉川一朗

      日本地球惑星科学連合大会予稿集(Web)2015   ROMBUNNO.PCG32‐P11 (WEB ONLY)   2015

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      Language:Japanese  

      J-GLOBAL

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    • 紫外線望遠鏡による系外惑星観測の検討

      堀越寛己, 池澤祥太, 桑原正輝, 村上豪, 亀田真吾, 吉川一朗, 田口真

      地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM)138th   ROMBUNNO.R009‐P34   2015

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    • 紫外線望遠鏡による系外惑星観測計画の検討状況

      亀田真吾, 池澤祥太, 村上豪, 成田憲保, 生駒大洋, 関根康人, 吉川一朗, 杉田精司

      日本地球惑星科学連合大会予稿集(Web)2015   ROMBUNNO.PCG32‐13 (WEB ONLY)   2015

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      J-GLOBAL

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    • HISAKI/EXCEEDで観測された磁気嵐中・ジオコロナのLyman‐αの増光

      桑原正輝, 吉岡和夫, 村上豪, 土屋史紀, 木村智樹, 亀田真吾, 佐藤允基, 吉川一朗

      地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM)136th   ROMBUNNO.S001‐11   2014

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      J-GLOBAL

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    • Lunar and planetary chronological missions based on the in-situ geochronology instruments(<Special issue>Planetary exploration in a coming decade activity: Reports of 2nd stage) Peer-reviewed

      Cho Y, Morota T, Miura Y. N, Kameda S

      Planetary People21 ( 3 ) 267 - 275   25 9 2012

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    • 「かぐや」による子午面撮像が明らかにしたプラズマポーズの形成

      村上豪, 吉川一朗, 吉岡和夫, 山崎敦, 鍵谷将人, 田口真, 菊池雅行, 亀田真吾, 中村正人

      地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM)130th   ROMBUNNO.B006-P009   2011

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    • 317 BepiColombo Euro-Japan Joint mission to Mercury

      Hayakawa Hajime, Ogawa Hiroyuki, Minesugi Kenji, Takashima Takeshi, Matsuoka Ayako, Nakazawa Satoru, Kameda Shingo, Yamakawa Hiroshi, Kasaba Yasumasa

      Abstracts Fall Meeting of the Japanese Society for Planetary Sciences2009   28 9 2009

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      Language:Japanese   Publisher:The Japanese Society for Planetary Sciences  

      CiNii Article

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    • BepiColombo/MMO搭載用ナトリウム大気光カメラMSASIの開発

      亀田真吾, 江沢福紘, 村上豪, 小川源太郎, 野澤宏大, 吉川一朗, 岡野章一, KORABLEV O, REES D

      太陽系科学シンポジウム29th   9 - 11   3 2008

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      J-GLOBAL

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    • Performance test of Image Intensifier used in the BepiColombo mission

      OGAWA Gentaro, MURAKAMI Go, EZAWA Fukuhiro, KAMEDA Shingo, YOSHIKAWA Ichiro

      JAXA research and development report7   1 - 12   2 2008

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      Language:Japanese   Publisher:Japan Aerospace Exploration Agency  

      The Mercury&#039;s Sodium Atmosphere Spectral Imager (MSASI) on Mercury Magnetospheric Orbiter (MMO)/ BepiColombo is under development. MSASI is a high-dispersion spectrometer working in the spectral range around sodium D 2 emission. The detector unit employs an Image Intensifier which has twostage micro channel plate (MCP). In this paper, we report the results of performance test for the Image Intensifier. We have focused on the following points. 1. Spectral resolution. 2. Dependency of Dark-Counts on temperature. 3. Radiation tolerance of phosphor (P 46). 4. Tolerance for aging against incident flux.

      CiNii Article

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    • BepiColombo水星探査計画に向けたナトリウム大気撮像カメラ用検出器の開発

      江沢福紘, 村上豪, 吉岡和夫, 小川源太郎, 亀田真吾, 吉川一朗

      地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM)124th   ROMBUNNO.B009-P017   2008

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    • 水星大気密度変動の地上観測

      亀田真吾, 小川源太郎, 江沢福紘, 村上豪, 吉岡和夫, 吉川一朗

      地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM)124th   ROMBUNNO.B009-09   2008

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    • 小型宇宙望遠鏡TOPSによる惑星電磁圏領域の科学目標

      土屋史紀, 寺田直樹, 山崎敦, 今井一雅, 深沢圭一郎, 二穴喜文, 鍵谷将人, 亀田真吾, 笠羽康正, 三澤浩昭, 森岡昭, 野澤宏大, 荻野竜樹, 佐藤毅彦, 垰千尋, 上野宗孝, 横田勝一郎, 吉川一朗, 渡部重十, 高橋幸弘

      地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM)122nd   ROMBUNNO.B009-P028   2007

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    Research Projects

    • 強紫外線輻射を受ける地球型惑星のハビタビリティ

      自然科学研究機構  アストロバイオロジーセンター サテライト研究 

      亀田真吾

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      4 2018 - Present

      Authorship:Principal investigator  Grant type:Competitive

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    • 太陽系外地球型惑星の高層大気観測に向けた高感度紫外線検出器の開発

      日本学術振興会  科学研究費助成事業 

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      4 2019 - 3 2022

      Grant type:Competitive

      Grant amount:\18400000 ( Direct Cost: \12880000 、 Indirect Cost:\5520000 )

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    • 太陽系外地球型惑星の水環境進化

      科学研究費助成事業 

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      4 2018 - 3 2021

      Grant type:Competitive

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    • 高感度紫外線分光器の開発

      文部科学省  JAXA戦略的基礎開発予算 

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      4 2019 - 3 2020

      Grant type:Competitive

      Grant amount:\9100000 ( Direct Cost: \8200000 、 Indirect Cost:\900000 )

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    • 宇宙望遠鏡搭載に向けた系外惑星観測用真空紫外線分光システムの検討

      宇宙航空研究開発機構  JAXA戦略的基礎開発予算 

      亀田真吾

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      4 2018 - 3 2019

      Authorship:Principal investigator  Grant type:Competitive

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    • 紫外線宇宙望遠鏡による太陽系外惑星大気の研究

      日本学術振興会  科学研究費助成事業 

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      4 2016 - 3 2019

      Grant type:Competitive

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    • WSO-UV搭載用紫外線分光器とコロナグラフ装置の開発

      宇宙航空研究開発機構  JAXA国際共同ミッション推進研究 

      亀田真吾

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      10 2017 - 3 2018

      Authorship:Principal investigator  Grant type:Competitive

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    • MMX搭載望遠/広角分光カメラの機器性能試験手法および設備の開発

      宇宙航空研究開発機構  受託研究(一般受託研究) 

      亀田真吾

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      4 2017 - 3 2018

      Authorship:Principal investigator  Grant type:Competitive

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    • 光検出器を用いた年代計測装置の開発

      宇宙航空研究開発機構  JAXA搭載機器基礎開発実験費 

      亀田真吾

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      4 2015 - 3 2016

      Authorship:Principal investigator  Grant type:Competitive

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    • 超小型深宇宙機搭載観測機器の開発

      宇宙航空研究開発機構  共同研究(国内共同研究) 

      亀田真吾

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      10 2013 - 3 2015

      Authorship:Principal investigator  Grant type:Competitive

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    • 真空紫外分光によるK-Ar年代測定

      宇宙航空研究開発機構  JAXA搭載機器基礎開発実験費 

      亀田真吾

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      4 2012 - 4 2013

      Authorship:Principal investigator  Grant type:Competitive

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    • 水星大気光観測による磁気圏と固体表面の相互作用に関する研究

      科学研究費補助金 

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      4 2011 - 3 2013

      Grant type:Competitive

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    • 惑星大気光観測用ファブリペロー干渉計の開発

      宇宙航空研究開発機構  JAXA搭載機器基礎開発実験費 

      亀田真吾

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      4 2010 - 3 2011

      Authorship:Principal investigator  Grant type:Competitive

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    • 月惑星大気光の超高分散分光観測に向けたファブリペロー干渉計用高精度平面鏡の開発

      科学研究費補助金 

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      4 2008 - 3 2010

      Grant type:Competitive

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    Industrial property rights

    • 光学機器に使用するための鏡をプレートに接着させる方法

      亀田真吾, 佐藤允基, 池澤祥太

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      Application no:2015-028424  Date applied:17 2 2015

      Announcement no:2016-150967  Date announced:22 8 2016

      Patent/Registration no:6562341  Date issued:2 8 2019

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