一个没有表面岩海洋的凉爽的失控温室
Franck Selsis1, Jérémy Leconte2, Martin Turbet2,3
1Laboratoire d'astrophysique de Bordeaux, University of Bordeaux, CNRS, Pessac, France. franck.selsis@u-bordeaux.fr.
Nature
|August 9, 2023
概括
星球上的纯蒸汽大气是由辐射层形成的, 不仅仅是对流层. 这意味着表面的岩海洋不像以前想象的那样,影响了系外行星的可居住性评估.
科学领域:
- 星球科学
- 气候模型
- 天体物理学
背景情况:
- 之前的模型假设完全对流的蒸汽大气, 预测表面的岩海洋.
- 这些假设是基于类似地球的含水量和高阳光照射或冲击场景.
研究的目的:
- 使用一致的气候模型研究纯蒸汽大气的热结构.
- 重新评估表面岩海洋形成和行星地固所需的条件.
主要方法:
- 使用一致的气候模型模拟纯蒸汽大气.
- 分析了辐射层,恒星光谱和内部热流对热结构的影响.
- 模型预测与之前的亚亚巴特结构假设进行了比较.
主要成果:
- 蒸汽大气主要由辐射层形成,使其热结构依赖于恒星光谱和内部热量.
- 表面温度较低,没有强加的亚热态形状;需要大量的阳光照射来化地球地.
- 在较冷的恒星周围不太可能存在表面的岩海洋,而金星表面可能会在蒸汽大气逃逸之前凝固.
结论:
- 重新思考表面岩海洋的形成以及陆地行星上的蒸汽大气的演变.
- 强调需要改进的不透明度测量以准确地建模系外行星大气层.
- 影响对系外行星质量半径关系和可居住性的理解,特别是对像TRAPPIST-1这样的系统.
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