In situ collection of dust grains falling from Saturn's rings into its atmosphere
In situ collection of dust grains falling from Saturn's rings into its atmosphere
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DOI：
10.1126/science.aat3185
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发表时间：
2018-10-05
期刊：
影响因子：
56.9
通讯作者：
Srama, Ralf
中科院分区：
文献类型：
--
作者：
Hsu, Hsiang-Wen;Schmidt, Jurgen;Srama, Ralf
土星的主要环由超过95%的水冰组成，剩下的几个百分比的性质仍然不清楚。卡西尼号航天器在土星和其最内层D环之间的穿越使其宇宙尘埃分析仪（CDA）能够收集从主环释放的物质，并描述落入土星的环物质。我们报告的直接原位检测的材料从土星的致密环的CDA影响质谱仪。大多数探测到的颗粒大小为几十纳米，与先前推断的“环雨”动态相关。“硅酸盐和水冰粒被确定，其比例随纬度而变化。硅酸盐颗粒占下落颗粒的30%，比环的整体硅酸盐含量更高。
Saturn's main rings are composed of >95% water ice, and the nature of the remaining few percent has remained unclear. The Cassini spacecraft's traversals between Saturn and its innermost D ring allowed its cosmic dust analyzer (CDA) to collect material released from the main rings and to characterize the ring material infall into Saturn. We report the direct in situ detection of material from Saturn's dense rings by the CDA impact mass spectrometer. Most detected grains are a few tens of nanometers in size and dynamically associated with the previously inferred "ring rain." Silicate and water-ice grains were identified, in proportions that vary with latitude. Silicate grains constitute up to 30% of infalling grains, a higher percentage than the bulk silicate content of the rings.