論文

査読有り
2020年9月

Thermophysical properties of the surface of asteroid 162173 Ryugu: Infrared observations and thermal inertia mapping

ICARUS
  • Yuri Shimaki
  • Hiroki Senshu
  • Naoya Sakatani
  • Tatsuaki Okada
  • Tetsuya Fukuhara
  • Satoshi Tanaka
  • Makoto Taguchi
  • Takehiko Arai
  • Hirohide Demura
  • Yoshiko Ogawa
  • Kentaro Suko
  • Tomohiko Sekiguchi
  • Toru Kouyama
  • Sunao Hasegawa
  • Jun Takita
  • Tsuneo Matsunaga
  • Takeshi Imamura
  • Takehiko Wada
  • Kohei Kitazato
  • Naru Hirata
  • Naoyuki Hirata
  • Rina Noguchi
  • Seiji Sugita
  • Shota Kikuchi
  • Tomohiro Yamaguchi
  • Naoko Ogawa
  • Go Ono
  • Yuya Mimasu
  • Kent Yoshikawa
  • Tadateru Takahashi
  • Yuto Takei
  • Atsushi Fujii
  • Hiroshi Takeuchi
  • Yukio Yamamoto
  • Manabu Yamada
  • Kei Shirai
  • Yu-ichi Iijima
  • Kazunori Ogawa
  • Satoru Nakazawa
  • Fuyuto Terui
  • Takanao Saiki
  • Makoto Yoshikawa
  • Yuichi Tsuda
  • Sei-ichiro Watanabe
  • 全て表示

348
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.icarus.2020.113835
出版者・発行元
ACADEMIC PRESS INC ELSEVIER SCIENCE

TIR, the thermal infrared imager on Hayabusa2, acquired high-resolution thermal images of the asteroid 162173 Ryugu for one asteroid rotation period on August 1, 2018 to investigate the thermophysical properties of the asteroid. The surface temperatures of Ryugu suggest that the surface has a low thermal inertia, indicating the presence of porous materials. Thermophysical models that neglect or oversimplify surface roughness cannot reproduce the flat diurnal temperature profiles observed during daytime. We performed numerical simulations of a thermophysical model, including the effects of roughness on the diurnal brightness temperature, the predictions of which successfully reproduced the observed diurnal variation of temperature. The global thermal inertia was obtained with a standard deviation of 225 +/- 45 J m(-2) S-0.5 K-1 which is relatively low but still within the range of the value estimated in our previous study (Okada et al., Nature 579, 518-522, 2020), confirming that the boulders on Ryugu are more porous in nature than typical carbonaceous chondrites. The global surface roughness (the ratio of the variance of the height relative to a local horizontal surface length) was determined as 0.41 +/- 0.08, corresponding to a RMS surface slope of 47 +/- 5 degrees. We identified a slightly lower roughness distributed along the equatorial ridge, implying a mass movement of boulders from the equatorial ridge to the mid-latitudes.

リンク情報
DOI
https://doi.org/10.1016/j.icarus.2020.113835
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000541752200010&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/j.icarus.2020.113835
  • ISSN : 0019-1035
  • eISSN : 1090-2643
  • Web of Science ID : WOS:000541752200010

エクスポート
BibTeX RIS