Chondrulelike objects in short-period comet 81P/Wild 2
Chondrulelike objects in short-period comet 81P/Wild 2
复制标题
DOI：
10.1126/science.1160995
复制
发表时间：
2008-09-19
期刊：
影响因子：
56.9
通讯作者：
Nakano, Tsukasa
中科院分区：
文献类型：
--
作者：
Nakamura, Tomoki;Noguchi, Takaaki;Nakano, Tsukasa
星尘号太空船带回了含有晶体物质的彗星样本，但这些物质的来源还没有得到很好的理解。我们在81 P/ Wild 2彗星上发现了四个结晶颗粒，它们显然是在高温下闪熔形成的，在质地、矿物学和成分上都与球粒相似。球粒是一种亚毫米级的粒子，主要存在于陨石中，被认为是在太阳星云内部形成的。彗星颗粒显示出的氧同位素组成类似于构成中到外小行星带的碳质陨石中的球粒。彗星中的球粒状物体的存在表明球粒已经被运送到寒冷的外太阳星云，并在早期太阳系中广泛分布。
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 oxygen isotope compositions similar to chondrules in carbonaceous chondrites that compose the middle- to- outer asteroid belt. The presence of the chondrulelike objects in the comet suggests that chondrules have been transported out to the cold outer solar nebula and spread widely over the early solar system.