在土星A环附近观察到的氧离子
J H Waite1, T E Cravens, W-H Ip
1Department of Atmospheric, Oceanic, and Space Physics, University of Michigan, Ann Arbor, MI 48109, USA.
Science (New York, N.Y.)
|February 26, 2005
概括
土星的A环有一个电离层,卡西尼号的INMS探测到氧离子和质子证实了这一点. 这种电离层可能是由太阳紫外线辐射与微薄的环形大气相互作用而形成的.
科学领域:
- 行星科学 行星科学
- 空间物理 空间物理
- 天体化学是天体化学.
背景情况:
- 土星的环主要由冰颗粒组成.
- 有人假设行星环周围存在微薄的大气层.
- 了解环的组成和相互作用是行星进化的关键.
研究的目的:
- 为了研究土星A环附近的离子的存在和组成.
- 为了确定环环境中检测到的离子的来源.
- 为了评估与土星环相关联的电离层的存在.
主要方法:
- 使用卡西尼轨道器上的离子和中性质谱仪 (INMS) 在现场检测离子.
- 分析卡西尼号在土星A环上空飞行期间的质谱数据.
- 离子信号与太阳辐射和潜在的中性物种的相关性.
主要成果:
- 在土星A环附近检测分子和原子氧离子和质子.
- 有证据表明与A环相关的电离层存在.
- INMS 中立测量在很大程度上被背景噪音所掩盖.
结论:
- 土星的A环有一个电离层.
- 太阳紫外线辐射对中性O2分子的光电化是观察到的离子的可信来源.
- 一个含有O2分子的微薄环形大气很可能存在.
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