Asteroid Ryugu Samples Arrived at Hokkaido University

Retrieved by the Hayabusa2 exploration mission, the samples of asteroid Ryugu arrived at Hokkaido University on June 21, 2021. The samples were personally delivered by Professor Shogo Tachibana from the School of Science, The University of Tokyo. Hokkaido University’s Professor Hisayoshi Yurimoto will lead a chemistry analysis team, one of the teams that will conduct the initial analyses on the samples, using Hokkaido University’s isotope microscope.

Professor Shogo Tachibana (far left), Professor Hisayoshi Yurimoto (far right), and the members of Yurimoto’s laboratory with the Ryugu samples.

Born 4.6 billion years ago, withstanding the tectonic forces and heat, Ryugu is believed to have recorded the memory of the solar system in its infantile period. Abundant with carbon, the asteroid is classified as a C-type asteroid, from which it is expected that we can find organic materials and water that are essential components of life on earth. Over the next one year, the preliminary analysis teams aim to uncover the mysteries surrounding the formation/ birth of the ocean and life, as well as the origin and evolution of the solar system.

In addition to the chemical analysis by Yurimoto’s team, these valuable samples will also be analyzed by different teams from the perspectives of the coarse grain compositions, fine grain compositions, volatile compounds, solid organic components, and soluble organic components.

Ryugu samples were packed and carried in a sealed pack of nitrogen gas to avoid contamination by the earth’s atmosphere.

The chemical analysis team will analyze the samples using the isotope microscope which has been developed at Yurimoto’s laboratory for over 30 years. In their research activities, this device captures the images of the fine distribution of elements’ isotopes from meteorite and asteroid samples. Isotopes are the same elements with different atomic weights. By analyzing the isotope ratios, they can learn about the age and origin of components/substances/ material.

Yurimoto is enthusiastic about this preliminary analysis. “The treasure chest has just been opened. From now on, we will inspect its content down to every nook and cranny,” he said.

Professor Hisayoshi Yurimoto, the leader of the chemical preliminary analysis team for the Hayabusa2 project.

Supervisor for the entire preliminary analysis team of Hayabusa2 Project, Professor Shogo Tachibana of The University of Tokyo.