東北大学 · Physics and Astronomy
Tomoki Nakamura 교수의 연구실은 태양계 소행성과 코메트에서 채굴된 천체 표면 미세입자를 분석하여 태양계의 기원과 진화 과정을 밝히는 데 초점을 맞추고 있습니다. 주로 헤이부사, 스타드라스트 등 탐사미션을 통해 회수된 미세먼지 표본을 고해상도 X선 회절 및 전자현미경 기법으로 분석하여, 수소, 산소 동위원소 조성, 수분 함유 화합물, 고온 형성 입자 등 태양계 내부의 열적 및 수성 화학 반응의 흔적을 규명하고 있습니다. 특히 태양계 외부에서 형성된 물질이 어떻게 내부 태양계로 이동했는지, 그리고 다양한 천체에서의 열적·수성 변화 과정을 실험과 관측을 통해 규명하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
The Hayabusa spacecraft successfully recovered dust particles from the surface of near-Earth asteroid 25143 Itokawa. Synchrotron-radiation x-ray diffraction and transmission and scanning electron microscope analyses indicate that the mineralogy and mineral chemistry of the Itokawa dust particles are identical to those of thermally metamorphosed LL chondrites, consistent with spectroscopic observations made from Earth and by the Hayabusa spacecraft. Our results directly demonstrate that ordinary
Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carb
The Stardust spacecraft returned cometary samples that contain crystalline material, but the origin of the material is not yet well understood. We found four crystalline particles from comet 81P/Wild 2 that were apparently formed by flash-melting at a high temperature and are texturally, mineralogically, and compositionally similar to chondrules. Chondrules are submillimeter particles that dominate chondrites and are believed to have formed in the inner solar nebula. The comet particles show oxy
The presence of abundant phyllosilicates in many carbonaceous chondrites indicates a prevailing activity of low-temperature aqueous alteration in primitive asteroids. However, among the hydrous carbonaceous chondrites known, more than 20 samples show evidence of having been heated at elevated temperatures with corresponding phyllosilicate dehydration. The mineralogical features of dehydration suggest that the heating occurred in situ in meteorites, which demonstrates that there are some hydrated
Abstract— Small particles 200 μm in diameter from the hydrous carbonaceous chondrites Orgueil CI, Murchison CM2, and Tagish Lake were experimentally heated for short durations at subsolidus temperatures under controlled ambient pressures in order to examine the bulk mineralogical changes of hydrous micrometeorites during atmospheric entry. The three primitive meteorites consist mainly of various phyllosilicates and carbonates that are subject to decomposition at low temperatures, and thus the br
