Joint Press Release
Shogo Tachibana, Professor at the Institute of Space and Planetary Science (ISAS) / Specially Appointed Professor at the Institute of Space and Astronautical Science (JAXA)

An international research group led by Associate Professor Yasuhiro Oba of the Institute of Low Temperature Science, Hokkaido University, Senior Researcher Yoshinori Takano of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), and Professor Hiroshi Naraoka of the Graduate School of Science, Kyushu University, has successfully detected uracil, a nucleobase contained in all RNA of Earth life, in particles from the asteroid Ryugu brought back by the asteroid probe “Hayabusa2 They succeeded in detecting uracil, a nucleobase contained in the RNA of all life on Earth, in a particle from the asteroid Ryugu brought back by the Hayabusa2 spacecraft. In addition, vitamin B3 (niacin), an important coenzyme related to the metabolism of life, was also detected in the same sample.

In December 2020, the asteroid Ryugu sample was delivered to Earth by the asteroid probe Hayabusa2, making it the world’s first sample collected directly from a carbonaceous asteroid to be analyzed in a laboratory (published in Science on February 10, 2022). The Soluble Organic Molecules Analysis Team, one of the initial analysis subteams, has previously demonstrated the presence of various organic compounds, such as amino acids and carboxylic acids, in Ryugu samples (published in Science on February 24, 2023). In this study, we focused on nitrogen-containing cyclic organic compounds (nitrogen heterocyclic compounds) and verified their presence in Ryugu samples in detail.

Using an ultra-sensitive analytical method developed by the research team, they succeeded in detecting uracil, one of the nucleobases contained in the RNA of all Earth life, and vitamin B3 (niacin), one of the coenzymes essential for the metabolism of life, in a Ryugu sample of about 10 milligrams. These detections provide a real picture of the chemical evolution of organic molecules and strongly support the theory that components supplied by extraterrestrial materials such as carbonaceous meteorites (i.e., asteroid fragments) were the materials for the ultimate mystery in science: how the first life on the primitive Earth was created before the birth of life. The results of this research are expected to be published in 2023.

For more information, please refer to the following

Graduate School of Science press release: https://www.s.u-tokyo.ac.jp/ja/info/8330/
Publication URL: https://doi.org/10.1038/s41467-023-36904-3

Joint Press Release
Professor Shogo Tachibana, Professor Seiji Sugita, Associate Professor Tomokatsu Morota, Special Staff Shizuho Furuya

Soluble organic molecules contained in the Ryugu sample brought back by Hayabusa2 were analyzed mainly by solvent extraction. Ryugu is a dark primitive asteroid belonging to the C-type asteroids, which are the most common in the asteroid belt, and is rich in hydrous minerals such as carbonaceous chondrite meteorites. Primitive carbonaceous chondrites are known to contain a variety of soluble organic molecules, including amino acids, and may have supplied preliving organic molecules that led to the birth of life to the early Earth and other celestial bodies. In this study, organic molecules contained in Ryugu surface samples obtained from the first touchdown sampling were analyzed by research teams from Japan, the U.S., and Europe. As a result, various organic molecules such as amino acids, amines, carboxylic acids, aromatic hydrocarbons, and nitrogen-containing cyclic compounds were detected. These organic molecules could be released from Ryugu’s surface and transported to other celestial bodies, or they could be used as organic resources.

For more information, please see

JAXA press release: https://www.jaxa.jp/press/2023/02/20230224-1_j.html
Graduate School of Science press release: https://www.s.u-tokyo.ac.jp/ja/info/8304/
Publication URL: https://www.science.org/doi/10.1126/science.abn9033

Joint Press Release
Professor Shogo Tachibana, Assistant Professor Taiga Okumura, Professor Yoshio Takahashi, Professor Seiji Sugita, Associate Professor Tomokatsu Morota, Special Staff Shizuho Furuya

The Solid Organic Matter Analysis Team, led by Professor Hikaru Yabuta of the Graduate School of Advanced Science and Engineering, Hiroshima University, analyzed the chemical composition, isotopic composition, and morphology of solid organic matter in the asteroid Ryugu sample brought back to Earth by the asteroid probe “Hayabusa2”. The non-destructive analysis of the Asteroid Ryugu sample (37 microparticles ranging in size from 200 to 900 μm) using various microspectroscopic techniques revealed that the types and proportions of chemical bonds comprising the organic matter in the sample were similar to those of the most primitive Ivuna-type carbonaceous chondrite (CI Group) and primitive Mighei-type carbonaceous chondrite (CM Group). Electron microscopic examination of them revealed nanometer-sized spherical organic matter and thinly spread irregularly shaped organic matter adjacent to or mixed with layered silicates and carbonates. Their coexistence with secondary minerals produced in Ryugu’s parent body is evidence that these organic materials also originated from reactions with liquid water in the parent body. The absence of graphite-like ordered structures in the Ryugu samples means that the organic matter in the Ryugu samples analyzed was not heated to high temperatures in the parent body interior or by impact.

In addition, the isotopic composition of the Ryugu sample revealed regions of deuterium and nitrogen15 concentrations. Such isotopic compositions are not found in terrestrial organic matter and are known to occur only in low-temperature environments of a few tens of Kelvin (minus 200°C or lower). Thus, the Ryugu organics analyzed are indeed of extraterrestrial origin, and at least some of these organics were formed in cryogenic environments such as interstellar molecular clouds and the outer protoplanetary disk.

For more information, please see

JAXA press release: https://www.jaxa.jp/press/2023/02/20230224-2_j.html
Graduate School of Science press release: https://www.s.u-tokyo.ac.jp/ja/press/2023/8303/
Publication URL: https://www.science.org/doi/10.1126/science.abn9057

Notice of cancellation

The symposium will be postponed due to the spread of the new coronavirus infection.
When the situation calms down, we would like to plan a similar meeting again

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We will hold the new Integrated Research System:
Collaborative Research organization for Space and Technology
(CROiSSanT) commemorative symposium on Monday 9th March at Koshiba Hall,
School of Science Bldg.1, The University of Tokyo.

ALMA image showing AlO around the star at wavelengths of 497 gigahertz(left) and 650 gigahertz (right). Image: © 2019 Astrophysical Journal Letters/Shogo Tachibana

Spatial distribution of AlO in a high mass protostar candidate Orion Source I

This research results appear in Astrophysical Journal Letters.

doi.org/10.3847/2041-8213/ab1653

Ryugu is a C-type asteroid – rich in carbon – about 900m wide. © 2019 Seiji Sugita et al., Science

Press release on paper published in Science led by Professor Sugita.

[Press release] Hayabusa2 probes asteroid for secrets

The RockSat-XN was launched on January 13th, 2019 from Andøya Space Center in Norway.

The scientific payloads for Japanese PARM (Pulsating AuroRa and Microbursts) project are installed on the RockSat-XN.
The group led by Satoshi Kasahara (School of Science) participated in this project. Students’ “hand-made” analyser was installed on the Rocket to measure the electron precipitation from space.

Associate Professor Takanobu Amano receives the AAPP-DPP Young Researcher Award from the Division of Plasma Physics, Association of Asia Pacific Physical Societies for his significant contributions to the simulation and theory of acceleration of non-thermal electrons in collisionless shocks in space and astrophysical plasmas.

Association of Asia Pacific Physical Societies, Division of Plasma Physics (AAPPS-DPP)

Young Researcher Award Winners