A research paper based on the direct observation of the subsurface materials of the asteroid Ryuguu by the asteroid explorer Hayabusa2(※1) was published in the British online journal Nature Astronomy(※2) on January 4, 2021 (January 5, Japan time).

The lead author of this paper is Associate Professor KITAZATO Kohei, who belongs to the University of Aizu Research Center for Space Informatics (※3) at the University of Aizu, and four other faculty members of the University of Aizu are also co-authors.

This paper reports the findings that the subsurface material of Ryugu is partially dehydrated by heating, just like the surface material, but has more water than the surface material, and that the heating occurred in the predecessor body of Ryugu, based on the observation data of the subsurface material of Ryugu using the Near Infrared Spectrometer (NIRS3) onboard Hayabusa2.

Associate Professor Kitasato led the instrument development, observation operation, and data analysis as the principal investigator of NIRS3, and wrote the main part of the paper.

This research result is expected to be an important indicator to interpret the analysis results of the Ryugu samples brought back to Earth by Hayabusa2.

<Paper title> Thermally altered subsurface material of asteroid (162173) Ryugu
Main Author: KITAZATO Kohei (Associate Professor,The University of Aizu)
Author affiliated with the University of Aizu: OHTAKE Makiko (Professor)
HIRATA Naru (Senior Associate Professor)
HONDA Chikatoshi (Associate Professor)
YAMADA Ryuhei (Associate Professor)
(Excerpts from University of Aizu faculty only・Order by author of paper)

(Publication date: January 6, 2021)