Itokawa Dust Particles: A Direct Link Between S-Type Asteroids and Ordinary Chondrites
Itokawa Dust Particles: A Direct Link Between S-Type Asteroids and Ordinary Chondrites
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DOI：
10.1126/science.1207758
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发表时间：
2011-08-26
期刊：
影响因子：
56.9
通讯作者：
Kawaguchi, Junichiro
中科院分区：
文献类型：
--
作者：
Nakamura, Tomoki;Noguchi, Takaaki;Kawaguchi, Junichiro
隼鸟号宇宙飞船成功地从近地小行星 25143 糸川表面回收了尘埃颗粒。同步辐射 X 射线衍射和透射以及扫描电子显微镜分析表明，糸川尘埃颗粒的矿物学和矿物化学与热变质 LL 球粒陨石相同，这与地球和隼鸟号航天器进行的光谱观测一致。我们的结果直接证明，地球上发现的最丰富的陨石——普通球粒陨石来自S型小行星。矿物化学表明，大多数风化层表面颗粒遭受了长期的热退火和随后的撞击冲击，这表明糸川是一颗由曾经较大的小行星内部碎片重新组装而成的小行星。
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 chondrites, the most abundant meteorites found on Earth, come from S-type asteroids. Mineral chemistry indicates that the majority of regolith surface particles suffered long-term thermal annealing and subsequent impact shock, suggesting that Itokawa is an asteroid made of reassembled pieces of the interior portions of a once larger asteroid.