UTokyo Organization for Planetary Space Science (UTOPS) cooperated with the “Special Exhibition of Asteroid Itokawa and Ryugu Samples in Akashi” held from January 27 (Sat) to February 18 (Sun), 2024, at the 3rd floor exhibition room “Astronomy Gallery” of Akashi Municipal Planetarium.
Samples from the asteroid Itokawa, brought back to Earth by the asteroid explorer Hayabusa in June 2010, and samples from the asteroid Ryugu, brought back to Earth by the asteroid explorer Hayabusa2 in December 2020, were displayed side by side.
Exhibition view: from https://www.am12.jp/topics/itokawaryugu/
In conjunction with the exhibition, Professor Shogo Tachibana gave a lecture entitled “What the Stones of Asteroid Ryugu Have Begun to Tell Us” on January 28, 2024, at the planetarium dome on the second floor of the museum.
02/18/2024Cooperated in the Special Exhibition of Asteroid Itokawa and Ryugu Samples at Akashi Municipal Planetarium はコメントを受け付けていませんNews, UTOPS-News Like
We co-organized the Solar System symposium in Sapporo 2024 from February 13 (Tue.) to 15 (Thu.), 2024, at the Rusutsu Resort in Hokkaido, Japan.
About 40 participants from Japan and overseas discussed the formation and early evolution of the solar system.
On the second day, February 14 (Wednesday), we invited Professor Harold C. Connolly Jr., OSIRIS-REx Mission Sample Scientist, to give a lecture on the return samples from the asteroid Bennu.
Professor Harold C. Connolly Jr. giving an invited lecture
Prof. Shogo Tachibana of UTOPS gave a lecture at the Winter School “Small bodies of the Solar System and their link with extraterrestrial samples” held in Les Houches, France from February 4 (Sun.) to February 9 (Fri.), 2024.
Joint Press Release Masahiro Hoshino (Professor, Department of Earth and Planetary Sciences ) Takanobu Amano, Associate Professor, Department of Earth and Planetary Science
A research group led by Masanori Iwamoto, Project Assistant Professor at the Institute for Fundamental Physics, Kyoto University, Yosuke Matsumoto, Associate Professor at the International Advanced Research Institute, Chiba University, Takanobu Amano, Associate Professor at the Graduate School of Science, University of Tokyo, Masahiro Hoshino, Professor at the Graduate School of Science and Engineering, Kyushu University, and Shuichi Matsukiyo, Professor at the Interdisciplinary Graduate School of Science and Engineering, Kyushu University, has successfully reproduced high-speed radio bursts using the supercomputer “Fugaku”.
A fast radio burst is the largest radio explosion in the universe, which suddenly shines in radio waves for a very short time. They are believed to originate from shock waves formed around neutron stars with extremely strong magnetic fields called magnetars, but until now there has been no theoretical support for this belief. The results of this very large-scale simulation of the shock wave by Fugaku have demonstrated for the first time that the radio waves in the simulation are consistent with previous observations and correctly reproduce fast radio bursts.
Since the radio signals of fast radio bursts contain information about the universe they pass through, it is thought that they can be used as a tool to explore the evolution and structure of the universe. To this end, it is important to understand where and how fast radio bursts are generated, and this research is expected to make great strides in this direction and to have a ripple effect on other fields such as cosmology.
The results of this research were published online in the U.S. international journal Physical Review Letters on January 16, 2024.
Figure: Shock wave structure at the end of the simulation. The left side depicts the magnetic field, with radio waves emitted toward the front. On the right is the plasma density, and an elongated structure is created by the radio waves.
For more information, please refer to the following
02/05/2024[Press Release] Successful Reproduction of High-Speed Radio Bursts by Fugaku -The Origin of the Universe’s Largest Radio Explosion はコメントを受け付けていませんNews, UTOPS-News Like
On Tuesday, January 23, 2024, Professor Shogo Tachibana of UTOPS gave a talk on Ryugu and Hayabusa2 to fifth graders at Nakamura Elementary School in Nerima Ward, Tokyo.
From the first to the fourth period, we went around to each class and interacted with energetic children.
Please refer to the following URLs 「宇宙のお話１」「宇宙のお話２」 for the scenes of the day.
Joint Press Release Shogo Tachibana (Professor, Department of Earth and Planetary Science, ISAS)
Since the surface of an asteroid is not covered by an atmosphere, solar winds and cosmic dusts fall on the asteroid and change the chemical composition and other characteristics of materials on the asteroid’s top surface. A research team led by Assistant Professor Megumi Matsumoto and Professor Tomoki Nakamura of the Department of Earth Sciences, Graduate School of Science, Tohoku University, in collaboration with Ritsumeikan University, Kyoto University, the University of Tokyo, and others, observed the surface of rock particles brought back from the asteroid Ryugu by the Hayabusa2 probe using a scanning electron microscope, and found that the surface of the asteroid is covered with molten materials of 5 to 20 micrometers in size, formed when small cosmic dust particles hit the asteroid. The team discovered several melts of 5 to 20 micrometers in size, which were formed by the impact of small cosmic dust particles on the asteroid’s surface. 3D CT observation and chemical composition analysis of the melts revealed that they were formed by the melting and mixing of dust from the impacting comet and Ryugu’s surface material at high temperatures.
Comets form in the distant part of the solar system and are known to contain a large amount of organic matter that could be the material for life. The formation of molten material from cometary dust impacts likely occurred in the orbit of the present-day asteroid Ryugu about 5 million years ago, suggesting that Ryugu was supplied with cometary dust containing organic matter from distant parts of the solar system until very recently.
The results of this study were published on January 19, 2024 in Science Advances, a journal published by the American Association for the Advancement of Science (AAAS).
Figure: (Left) Melt found on the surface of Ryugu particle. It is rounded and looks like a drop of water. (Right) CT image of a cross-section of the melt. It can be seen that it contains many bubbles.
For more information, please refer to the following
01/23/2024[Press Release] Discovery of Traces of Cometary Dust Impact on Asteroid Ryugu -Suggests that Cometary Dust Containing Organic Matter Was Supplied from Distant Parts of the Solar System はコメントを受け付けていませんNews, UTOPS-News Like
On January 20 (Sat.) and 21 (Sun.), 2024, we held an astronomy training for students from Suwa Seiryo High School, Suwa Futaba High School, Matsumoto Misuzugaoka High School in Nagano Prefecture, and Ena High School in Gifu Prefecture. The students estimated the distance to galaxies from photographs of galaxies and used the recession speeds of these galaxies to determine the age of the universe.
01/22/2024Held an Astronomy Workshop for High School Students はコメントを受け付けていませんNews, UTOPS-News Like
Joint Press Release Shogo Tachibana (Professor, Department of Earth and Planetary Science, ISAS)
Reflection spectra of asteroid recovered samples and meteorites provide clues to identify the constituent materials of asteroids from observationally obtained reflection spectra of asteroids.
A research group led by graduate student Kana Amano (currently a visiting researcher) and Professor Tomoki Nakamura of the Department of Earth Sciences, Graduate School of Science, Tohoku University, researcher Moe Matsuoka of the National Institute of Advanced Industrial Science and Technology (AIST), and Professor Shogo Tachibana of the Department of Earth and Planetary Science, Institute of Space and Planetary Science, Graduate School of Science, the University of Tokyo, and their colleagues have been studying asteroid samples recovered by the asteroid probe Hayabusa2 from asteroid Ryugu sample recovered from the asteroid Ryugu by the asteroid explorer Hayabusa2, and measured the reflection spectrum of the sample by devising a way to prevent it from reacting with the Earth’s atmosphere. By comparing Ryugu samples, meteorites from the same type of asteroid as Ryugu, and experimentally heated meteorites, they showed that the reaction of the meteorites with water and oxygen in the Earth’s atmosphere changed their reflection spectra to be brighter than they were in space. Based on this achievement, 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: Reflectance spectra of Ryugu sample (blue line in graph), unheated CI-type meteorite (black dotted line), and CI-type meteorite heated at 300°C (red line).
For more information, please refer to the following
12/08/2023[Press Release] Why Ryugu’s Rock Samples Are Blacker than Primitive Meteorites -Meteorites Flying to Earth Reacted with the Atmosphere and Became Brighter はコメントを受け付けていませんNews, UTOPS-News Like
