研究者業績
基本情報
- 所属
- 国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 宇宙機応用工学研究系 はやぶさ２プロジェクト 准教授
- 学位
- 理学博士(1989年3月 東京大学)
- 連絡先
- yoshikawa.makoto
jaxa.jp - J-GLOBAL ID
- 200901037361657011
- researchmap会員ID
- 1000304540
研究キーワード
6経歴
5-
2003年10月 - 現在
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1998年4月 - 2003年9月
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1991年4月 - 1998年3月
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1996年12月 - 1997年12月
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1989年4月 - 1991年3月
学歴
2-
1984年4月 - 1989年3月
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1980年4月 - 1984年3月
委員歴
9-
2020年10月 - 現在
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1994年4月 - 現在
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2013年1月 - 2015年3月
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2011年1月 - 2012年12月
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2009年 - 2011年
受賞
2-
2019年11月
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2018年12月
論文
260-
European Space Agency, (Special Publication) ESA SP (500) 277-279 2002年7月During the 2001 Leonids storm over Japan, several short-duration "outbursts" in which more than 20-40 meteors appeared in a few seconds, have been reported. The meteors in these events were extremely localized within a few hundred km, which indicate the recent fragmentation of meteoroids during the orbital motion in the interplanetary space. Considering the extent of the spatial distribution, the fragmentation should have occurred at around the perihelion passage of the meteoroids just before encountering the Earth. This suggests the possible existence of the glue, which connects several refractory particles in fresh meteoroids.
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European Space Agency, (Special Publication) ESA SP (500) 331-333 2002年7月The MUSES-C mission is the first sample return mission from asteroid. It will be launched in the end of 2002, arrive at one of the Near-Earth Asteroid (25143) 1998 SF36 in 2005, and come back to the Earth in 2007. In this paper, the orbital evolution of this target asteroid is studied. Since this asteroid is almost in the ecliptic plane and the orbit crosses the orbits of the Earth and Mars, many close encounters with the Earth and Mars occur. Therefore, the motion of this asteroid is chaotic. We studied the orbital evolution of this asteroid by calculating the motions for many similar initial conditions. The results show that it is most probable that this asteroid exist around the present orbit for about several thousand years to the past or maybe for much longer period.
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Proceedings of SPIE - The International Society for Optical Engineering 4836 83-87 2002年We developed a new 1.0 m telescope with a 3 degree flat focal plane to which a mosaic CCD camera with 10 2k×4k chips is fixed. The system was set up in February 2002, and is now undergoing the final fine adjustments. Since the telescope has a focal length of 3 m, a field of 7.5 square degrees is covered in one image. In good seeing conditions, 1.5 arc seconds, at the site located in Bisei town, Okayama prefecture in Japan, we can expect to detect down to 20th magnitude stars with an exposure time of 60 seconds. Considering a read-out time, 46 seconds, of the CCD camera, one image is taken in every two minutes, and about 2,100 square degrees of field is expected to be covered in one clear night This system is very effective for survey work, especially for Near-Earth-Asteroid detection.
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Journal of the Communications Research Laboratory 48(1) 143-150 2001年3月Radar observations of two near-Earth asteroids were performed using a bi-static radar technique with Kashima 34-m antenna and Usuda 64-m antenna as receiving stations and Goldstone 70-m antenna as a transmitting station. The asteroid 6489 Golevka was observed on June 15, 1995 when its distance from the Earth became 0.048 AU and the radar echo from the asteroid was detected from the data observed with Kashima 34-m antenna. The success of the trans-continental bistatic radar observations became the first detection of a radar echo from a solar system object beyond Moon in Japan. The asteroid 4197 (1982 TA) was observed on October 24, 1996 when its distance to the Earth became 0.086 AU. The radar echo signal from the asteroid was detected from both of the data observed at Kashima and at Usuda. The received signal was coherently sampled and recorded at both stations. By using these data, interferometric data analysis was examined.
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Science and Technology Series 100 75-84 2001年Leonids meteoroids raised attention in space organizations in the world due to probable collision hazards to artificial satellites. This paper describes the plan of the Leonids measurement campaign in Japan and the results. The correlation between optical and radiowave observations was especially focused on. The countermeasures to lessen the Leonids hazards to satellites will also be presented.
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Annals of the New York Academy of Sciences 822 140-144 1997年The Spaceguard Project proposes to set up a network of five ground-based telescopes, each with an aperture of 2-3 m. With ground-based telescopes, there is a blind celestial area surrounding the Sun (say, within 30 degrees), in which an asteroid approaching the Earth cannot be detected optically because of bright sky background. Our study shows that the number of close approaches of asteroids coming from this area to within a minimum distance of less than 0.01 AU of the Earth is more than 30% of the total.
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Earth, Moon and Planets 72(1-3) 263-266 1996年We have estimated close asteroid encounters with the Earth by numerical integrations of a system with the Sun, 9 planets, and 188 near-earth-asteroids during the period 1994-4600. Asteroids approach the Earth from directions within 30° around the Sun in more than 20% of encounters with the closest distance less than 0.01 AU. Since groundbased observations cannot detect these objects, we should develop space-borne and/or lunar observatories in a short time to allow enough warning time before a catastrophic collision. © 1996 Kluwer Academic Publishers.
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1996信学総大 14(1) 625-626 1996年近年,将来の情報化社会にむけての世界的規模の情報通信基盤の構築が話題になっている.地上系の光ファイバーネットワークにおいてはGbitクラスの伝送速度が実現され実用化されているが衛星回線の伝送速度は100Mbps程度である.今後,衛星系を含めた地球規模の情報通信基盤ネットワークを構築するにあたってはこの衛星系の伝送速度を大幅にあげることが重要になる.郵政省通信総合研究所(CRL)では将来的にGbitクラスの衛星通信システムの構築を目指している.高速伝送を実現するためには中継器の広帯域化が必要であるが,この要求を満足するにはより高い周波数帯の利用が効果的である.CRLでは以前よりKa-bandを用いて衛星通信実験を行ってきており,この経験を生かして,このシステム実現のための第一歩として技術試験衛星VI型(ETS-VI)に搭載されたKa-band200MHzの帯域を持つ中継器を用いて伝送速度156MbpsでのHDTV伝送実験を計画していた.しかしながら,ETS-VIの静止化断念により,CRLではNTT所有の衛星であるN-Starを用いてNTTと共同で実験を行うことを決定した.本発表ではこの実験のシステムと予定されている実験項目について紹介する.
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Proc. of "Asteroids, Comets, Meteors 1991" (Lunar & Planetary Institute, Houston, Texas) 433-438 1992年
MISC
498-
ASTROPHYSICAL JOURNAL LETTERS 935(1) 2022年8月16日We have conducted a NanoSIMS-based search for presolar material in samples recently returned from C-type asteroid Ryugu as part of JAXA's Hayabusa2 mission. We report the detection of all major presolar grain types with O- and C-anomalous isotopic compositions typically identified in carbonaceous chondrite meteorites: 1 silicate, 1 oxide, 1 O-anomalous supernova grain of ambiguous phase, 38 SiC, and 16 carbonaceous grains. At least two of the carbonaceous grains are presolar graphites, whereas several grains with moderate C isotopic anomalies are probably organics. The presolar silicate was located in a clast with a less altered lithology than the typical extensively aqueously altered Ryugu matrix. The matrix-normalized presolar grain abundances in Ryugu are 4.8$^{+4.7}_{-2.6}$ ppm for O-anomalous grains, 25$^{+6}_{-5}$ ppm for SiC grains and 11$^{+5}_{-3}$ ppm for carbonaceous grains. Ryugu is isotopically and petrologically similar to carbonaceous Ivuna-type (CI) chondrites. To compare the in situ presolar grain abundances of Ryugu with CI chondrites, we also mapped Ivuna and Orgueil samples and found a total of SiC grains and 6 carbonaceous grains. No O-anomalous grains were detected. The matrix-normalized presolar grain abundances in the CI chondrites are similar to those in Ryugu: 23 $^{+7}_{-6}$ ppm SiC and 9.0$^{+5.3}_{-4.6}$ ppm carbonaceous grains. Thus, our results provide further evidence in support of the Ryugu-CI connection. They also reveal intriguing hints of small-scale heterogeneities in the Ryugu samples, such as locally distinct degrees of alteration that allowed the preservation of delicate presolar material.
書籍等出版物
19講演・口頭発表等
32担当経験のある科目(授業)
8-
2019年4月 - 現在太陽と太陽系の科学 (放送大学)
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2011年4月 - 現在位置天文学・天体力学 (東京大学)
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2007年4月 - 現在宇宙科学 (玉川大学)
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2006年4月 - 現在宇宙システム工学特論 III (総合研究大学院大学)
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2006年 - 現在宇宙工学概論 (総合研究大学院大学)
共同研究・競争的資金等の研究課題
15-
日本学術振興会 科学研究費助成事業 2023年4月 - 2026年3月
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日本学術振興会 科学研究費助成事業 基盤研究(B) 2018年4月 - 2021年3月
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日本学術振興会 科学研究費助成事業 基盤研究(C) 2016年4月 - 2019年3月
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日本学術振興会 科学研究費助成事業 2003年 - 2006年
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日本学術振興会 科学研究費助成事業 2003年 - 2005年
