概括
在金星的外层中氧离子重组产生快速的氧原子,驱动气逃逸. 这一过程随着时间的推移增加了与的比率,这表明过去有相当大的水量.
科学领域:
- 行星科学 行星科学
- 大气化学 大气化学
- 外层层的动力学 外层层的动力学
背景情况:
- 金星上层大气中的O(2)(+) 离子的重组是一个关键过程.
- 这一过程产生了快速的氧原子,可以与其他大气成分相互作用.
研究的目的:
- 调查O(2)(+) 重组在从金星逃出气中的作用.
- 分析与的比率和过去的水资源丰富性的影响.
主要方法:
- 对大气逃生机制的分析.
- 模拟外层中的离子-分子反应和原子碰撞.
- 解释来自诸如"先金星"等太空任务的数据.
主要成果:
- 氧的再组合导致大约10的原子/cm2/s逃逸.
- 逃逸是可以忽略不计的,导致D/H比率随着时间的推移而增加.
- 先金星观测到的质量-2离子很可能是D(+),表明当代D/H比为~10(-2).
结论:
- 当代高的D/H比率意味着一个初始比率为5 x 10{-5}.
- 这表明金星早期大气中的原始水 (H2O) 丰富度至少为800g/cm2.
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