氨基酸的缓慢放射溶解在类似火星永久土的条件下:在火星上寻找现存生命的应用
Alexander A Pavlov1, Hannah L McLain1,2,3, Kendra K Farnsworth1,3,4
1Solar System Exploration Division, NASA Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA.
Astrobiology
|August 11, 2025
概括
火星上的有机分子,对于检测生命至关重要,可以在冰中存活超过5000万年. 这表明纯冰或永久土地区是未来火星任务寻找生命的首要目标.
科学领域:
- 天体生物学 天体生物学
- 行星科学 行星科学
- 辐射化学 辐射化学
背景情况:
- 未来的火星任务旨在检测现有生命,需要了解有机生物特征的保存.
- 宇宙射线会降解火星上的有机分子,可能会破坏生命的证据.
研究的目的:
- 为了确定火星地下冰中氨基酸的放射性降解速率.
- 为了评估在火星表面辐射条件下有机生物特征的生存时间.
主要方法:
- 在H2O冰和酸盐矩阵中的氨基酸 (纯和来自大肠杆菌) 被暴露在玛辐射中.
- 在不同的冰温度下测量了放射性降解率.
- 研究了蒙莫里隆石的保护作用.
主要成果:
- 火星冰中的氨基酸可以在超过5000万年的宇宙射线暴露中生存.
- 降解速度随着冰的温度升高而增加.
- 蒙莫里隆石没有提供额外的辐射保护.
结论:
- 火星的浅冰层地下环境对保存有机生物特征充满希望.
- 对于未来的样本采集,应优先考虑纯冰或以冰为主导的永久土地区.
- 了解放射溶解是解释在寻找火星生命中的生物标志的关键.
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