Yayoi N. Miura
A5076596806- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Space Exploration and Technology
- Nuclear Physics and Applications
- Geology and Paleoclimatology Research
- Geological and Geochemical Analysis
- Space Science and Extraterrestrial Life
- Methane Hydrates and Related Phenomena
- earthquake and tectonic studies
- Spacecraft and Cryogenic Technologies
- High-pressure geophysics and materials
- Marine and environmental studies
- Laser-induced spectroscopy and plasma
- Archaeology and ancient environmental studies
- Paleontology and Stratigraphy of Fossils
- Geochemistry and Elemental Analysis
- Spectroscopy and Laser Applications
- Quantum, superfluid, helium dynamics
- Foot and Ankle Surgery
- Geochemistry and Geologic Mapping
- Atomic and Subatomic Physics Research
- Geological and Geophysical Studies
- Atmospheric Ozone and Climate
- Lower Extremity Biomechanics and Pathologies
The University of Tokyo
2011-2024
Association for the Development of Earthquake Prediction
2021-2022
Earthquake Engineering Research Institute
2012-2021
Osaka University
2009
Nagoya University
2003
Okayama University
1991-1996
Planetary Science Institute
1993
Abstract C-type asteroids 1 are considered to be primitive small Solar System bodies enriched in water and organics, providing clues the origin evolution of building blocks life. asteroid 162173 Ryugu has been characterized by remote sensing 2–7 on-asteroid measurements 8,9 with Hayabusa2 (ref. 10 ). However, ground truth provided laboratory analysis returned samples is invaluable determine fine properties other planetary bodies. We report preliminary results analyses on from particle size...
The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. mission performed two landing operations to collect samples of surface and subsurface material, latter exposed by an artificial impact. We present images second touchdown site, finding that ejecta from impact crater was at sample location. Surface pebbles both sites show morphological variations ranging rugged smooth, similar Ryugu's boulders, shapes quasi-spherical flattened. were returned Earth on 6...
We have prepared an artificial mixture of 3He and 4He to be used as internal standard for precise 3He/4He measurements terrestrial mantle-derived samples. The is named HESJ (He Standard Japan). ratio was determined by obtaining the weighted average repeated analyses from five machines in four laboratories Japan. recommended value relative air (R/Ra) 20.63 ± 0.10. available all researchers.
Noble gas isotopes were measured in three rocky grains from asteroid Itokawa to elucidate a history of irradiation cosmic rays and solar wind on its surface. Large amounts helium (He), neon (Ne), argon (Ar) trapped various depths the observed, which can be explained by multiple implantations particles into grains, combined with preferential He loss caused frictional wear space-weathered rims grains. Short residence time less than 8 million years was implied for an estimate...
The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth's volatiles. Samples were retrieved by Hayabusa2 spacecraft. We measured noble gas and nitrogen isotopes in samples found they are dominated presolar primordial components, incorporated during Solar System formation. Noble concentrations higher than those Ivuna-type (CI) chondrite meteorites. Several host phases isotopically distinct have...
Eucrites are a class of basaltic meteorites that share common mineralogical, isotopic, and chemical properties thought to have been derived from the same parent body, possibly asteroid 4 Vesta. The texture, mineralogy, noble gas data recently recovered meteorite, Northwest Africa (NWA) 011, similar those eucrites. However, oxygen isotopic composition NWA011 is different other eucrites, indicating may be body. presence with variable suggests occurrence multiple meteorite bodies, perhaps...
Abstract Phobos and Deimos occupy unique positions both scientifically programmatically on the road to exploration of solar system. Japan Aerospace Exploration Agency (JAXA) plans a sample return mission (MMX: Martian Moons eXploration). The MMX spacecraft is scheduled be launched in 2024, orbit (multiple flybys), retrieve >10 g regolith back Earth 2029. represents mixture endogenous building blocks exogenous materials that contain system projectiles (e.g., interplanetary dust particles...
The Hayabusa2 spacecraft returned to Earth from the asteroid 162173 Ryugu on 6 December 2020. One day after recovery, gas species retained in sample container were extracted and measured on-site stored collection bottles. consists of helium neon with an extraterrestrial 3 He/ 4 He 20 Ne/ 22 Ne ratios, along some contaminant terrestrial atmospheric gases. A mixture solar Earth’s is best explanation for composition. Fragmentation grains within discussed basis estimated amount indigenous size...
The nuclear magnetization of hcp solid $^{3}\mathrm{He}$ has been measured for molar volumes ranging from 18.1 to 19.4 ${\mathrm{cm}}^{3}$/mol and at temperatures down 43 \ensuremath{\mu}K. follows the Curie-Weiss law with a positive Weiss temperature, indicating that dominant spin interactions are ferromagnetic.
Carbonaceous chondrites are considered to have originated from C-type asteroids and represent some of the most primitive material in our solar system. Furthermore, since carbonaceous can contain significant quantities volatile elements, they may played a crucial role supplying volatiles organic Earth other inner system bodies. However, major challenge unravelling composition chondritic meteorites is distinguishing between which features were inherited parent body, what be secondary feature...
The static nuclear magnetization of bcc solid $^{3}\mathrm{He}$ has been measured for molar volumes ranging from 23.91 down to 21.20 ${\mathrm{cm}}^{3}$/mol, at temperatures between 10 mK and 70 \ensuremath{\mu}K. order antiferromagnetically all the studied. precise scaling with its maximum value ${M}_{\mathrm{max}}$ ordering temperature ${T}_{\mathrm{N}}$ is found fail, unlike case a previous experiment much narrower range volumes. values Weiss CTHETA are compared those obtained by other workers.
Two noble gas mass spectrometry systems (MS-I and MS-II) have been installed in 1989, one of which was designed our laboratory for Ar isotope analysis to measure K-Ar age by dilution method using 38Ar-spike. The whole system modified improved obtain high quality data. composed an extraction purification line a Modified-VG5400 spectrometer enables us determine precise composition easily speedily irrespective operator's skillfulness.Formulas calculating radiogenic 40Ar abundance, takes account...
The Hayabusa2 spacecraft explored C-type near-Earth asteroid (162173) Ryugu and returned asteroidal materials, collected during two touchdown operations, to the Earth as first sample from carbonaceous-type asteroid. container, in which ~5 g of was enclosed, safely opened clean chamber system with no severe exposure terrestrial atmosphere. In course preparation operation dark-colored millimeter- sub-millimeter-sized particles were found outside sealing part container. Because they look...
Abstract Developing a cleanroom and clean chambers (CCs) for Hayabusa2 returned samples has been discussed with the committee sample curation facility since 2015. One major difference from specifications of CCs used Itokawa is that part was decided to be handled preserved in vacuum avoid terrestrial nitrogen contamination organics or unknown materials might easily react samples. Thus, were divided into two processes three purified conditions. The built summer 2017, while installed 2018....
Abstract Hayabusa2 returned surface samples from the C-type near-Earth asteroid (162173) Ryugu to Woomera, South Australia, in December 2020. The are expected contain not only volatile components reflecting its primitive nature, but also solar wind due exposure space. Such volatiles may partly be released inside sealed sample container enclosing particle destruction or heating a contingency case. In order collect and analyze prior container-opening, we set up gas extraction analyses system...
Because of the almost total lack geological record on Earth's surface before 4 billion years ago, history Earth during this period is still enigmatic. Here we describe a practical approach to tackle formidable problems caused by lack. We propose that examinations lunar soils for light elements such as He, N, O, Ne, and Ar would shed new dark age in resolve three most fundamental questions earth science: onset time geomagnetic field, appearance an oxygen atmosphere, secular variation...