Neutron Activation Analysis of a Particle Returned from Asteroid Itokawa

被引：61

作者：

Ebihara, M. ^{[1
]}

Sekimoto, S. ^{[2
]}

Shirai, N. ^{[1
]}

Hamajima, Y. ^{[3
]}

Yamamoto, M. ^{[3
]}

Kumagai, K. ^{[1
]}

Oura, Y. ^{[1
]}

Ireland, T. R. ^{[4
]}

Kitajima, F. ^{[5
]}

Nagao, K. ^{[6
]}

Nakamura, T. ^{[7
]}

Naraoka, H. ^{[5
]}

Noguchi, T. ^{[8
]}

Okazaki, R. ^{[5
]}

Tsuchiyama, A. ^{[9
]}

Uesugi, M. ^{[10
]}

Yurimoto, H. ^{[11
]}

Zolensky, M. E. ^{[12
]}

Abe, M. ^{[10
]}

Fujimura, A. ^{[10
]}

Mukai, T. ^{[10
]}

Yada, Y. ^{[10
]}

机构：

[1] Tokyo Metropolitan Univ, Dept Chem, Tokyo 1920397, Japan

[2] Kyoto Univ, Inst Res Reactor, Osaka 59004, Japan

[3] Kanazawa Univ, Low Level Radioact Lab, Tatsunokuchi, Japan

[4] Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT, Australia

[5] Kyushu Univ, Dept Earth & Planetary Sci, Fukuoka 812, Japan

[6] Univ Tokyo, Geochem Res Ctr, Tokyo, Japan

[7] Tohoku Univ, Dept Earth & Planetary Mat Sci, Sendai, Miyagi 980, Japan

[8] Ibaraki Univ, Coll Sci, Mito, Ibaraki, Japan

[9] Osaka Univ, Dept Earth & Space Sci, Toyonaka, Osaka 560, Japan

[10] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa, Japan

[11] Hokkaido Univ, Sapporo, Hokkaido, Japan

[12] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA

来源：

SCIENCE | 2011年 / 333卷 / 6046期

关键词：

HAYABUSA SPACECRAFT; ORDINARY CHONDRITES; COMPONENTS; CHONDRULES; MINERALS; HISTORY; ORIGIN; METAL;

D O I：

10.1126/science.1207865

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

A single grain (similar to 3 micrograms) returned by the Hayabusa spacecraft was analyzed by neutron activation analysis. This grain is mainly composed of olivine with minor amounts of plagioclase, troilite, and metal. Our results establish that the Itokawa sample has similar chemical characteristics (iron/scandium and nickel/cobalt ratios) to chondrites, confirming that this grain is extraterrestrial in origin and has primitive chemical compositions. Estimated iridium/nickel and iridium/cobalt ratios for metal in the Itokawa samples are about five times lower than CI carbonaceous chondrite values. A similar depletion of iridium was observed in chondrule metals of ordinary chondrites. These metals must have condensed from the nebular where refractory siderophile elements already condensed and were segregated.

引用

页码：1119 / 1121

页数：3

共 17 条

[1] Near-infrared spectral results of asteroid Itokawa from the Hayabusa spacecraft [J].