Tohoku University

National Institute of Advanced Industrial Science and Technology

School of Science, The University of Tokyo

 

Summary of presentation

A research group led by graduate student Kana Amano (currently Visiting Scientist) and Professor Tomoki Nakamura of the Department of Earth Science, Graduate School of Science, Tohoku University, Dr. Moe Matsuoka (Research Scientist, the National Institute of Advanced Industrial Science and Technology (AIST)), and Professor Shogo Tachibana, School of Science, The University of Tokyo, has been studying the asteroid samples recovered by the asteroid probe Hayabusa2. The reflection spectra of the samples were measured studied without exposure to the Earth's atmosphere. By comparing the Ryugu sample, a meteorite that came from the same type of asteroid as Ryugu, and an experimentally heated sample of the meteorite, they showed that the reaction of the meteorite with water and oxygen in the Earth's atmosphere changed its reflection spectrum to be brighter than it was in space. Based on this result, it is expected that the accuracy of identifying the constituent materials of asteroids by observation will be improved by considering how the reflection spectra of meteorites can change due to their alteration on the ground.

This result was published in Science Advances, a journal published by the American Association for the Advancement of Science (AAAS), on December 7, 2023.

Figure:Reflection spectra of the Ryugu sample (blue line in the graph), an unheated CI-type meteorite (black dotted line), and a CI-type meteorite heated at 300 degrees (red line). The reflectance spectra of the Ryugu sample and the CI-type meteorite heated at 300°C are in good agreement in terms of the overall low reflectance, features around 3 microns in wavelength, and features around 10 microns in wavelength. Modified Figure 5A in the paper.

Professor Shogo Tachibana and Professor Yoshio Takahashi of the Department of Earth and Planetary Science participated in this research result.

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Journal

Journal name	Science Advances
Title of paper	Reassigning CI chondrite parent bodies based on reflectance spectroscopy of samples from carbonaceous asteroid Ryugu and meteorites