在火星上观察到的甲变化无法通过已知的大气化学和物理学来解释
Franck Lefèvre1, François Forget
1LATMOS, UPMC Université Paris 06, CNRS, Paris 75005, France. franck.lefevre@upmc.fr
Nature
|August 8, 2009
概括
火星上的甲显示季节性变化,但目前的模型无法解释这一点. 需要更快的甲损失过程,这表明火星的恶劣环境不适合有机生存.
科学领域:
- 行星科学 行星科学
- 天体生物学 天体生物学
- 大气化学 大气化学
背景情况:
- 在火星上检测到的甲引发了关于过去/现存生命与非生态起源的争论.
- 观察到的甲度显示了局部增强和季节性变化,这与其漫长的光化学寿命相矛盾.
研究的目的:
- 研究火星甲变异对我们对甲化学的理解的影响.
- 为了协调观察到的甲动态和当前的光化学模型之间的差异.
主要方法:
- 利用火星的全球气候模型与相结合的化学.
- 研究了光化学和二氧化碳凝聚-升华周期对甲分布的影响.
- 模拟甲释放场景,以评估大气寿命要求.
主要成果:
- 标准的光化学无法解释观察到的甲变化,即使是局部的,偶发的释放.
- 二氧化碳凝聚-升华循环产生大规模的甲变化,但与观察到的模式不匹配.
- 复制局部甲增强需要大气寿命<200天,这意味着一个未知的,快速的甲损失过程.
结论:
- 目前对火星甲化学的理解尚不完整.
- 一个未识别的甲损失过程,比预测的要快得多,是解释观测所必需的.
- 如果得到证实,这些变异表明火星表面的恶劣环境对有机物生存有害.
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