Formation of a hybrid-type proto-atmosphere on Mars accreting in the solar nebula
Formation of a hybrid-type proto-atmosphere on Mars accreting in the solar nebula
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火星上混合型原大气在太阳星云中吸积的形成
DOI：
10.1093/mnras/stx3176
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发表时间：
2018
影响因子：
4.8
通讯作者：
K. Kuramoto
中科院分区：
文献类型：
--
作者：
Hiroaki Saito;K. Kuramoto
最近对火星陨石年代学的研究表明，火星的生长几乎在太阳系诞生后的几百万年内完成。在这种快速的吸积过程中，原火星可能在重力作用下维持了太阳星云成分和撞击脱气成分，其中包含H2O蒸汽和还原气体，作为一种被称为混合型原大气的原大气。在这里，我们数值分析的质量和组成的脱气组件和大气的热结构持续的吸积加热。我们的研究结果预测，成长中的火星可能获得了巨大而炎热的混合型原始大气，其表面压力和温度分别大于几千巴和2000 K，足以产生深层岩浆海洋。在这样的高温高压环境中，大量的H2O、CH4、CO和H2预计将被分配到行星内部，尽管这在很大程度上取决于岩浆海洋和地幔凝固的动力学。溶解的H2O可能解释了从玄武岩火星陨石暗示的潮湿火星地幔。沿着流体动力大气逃逸后残留的还原性大气，溶解的还原性气体物种可能保持了最早的火星表面环境，允许生物前的化学进化和液态H2O活动。
Recent studies of the chronology of Martian meteorites suggest that the growth of Mars was almost complete within a few Myr after the birth of the Solar system. During such rapid accretion, proto-Mars likely gravitationally maintained both the solar nebula component and the impact degassing component, containing H2O vapour and reduced gas species, as a proto-atmosphere to be called a hybrid-type proto-atmosphere. Here we numerically analyse the mass and composition of the degassed component and the atmospheric thermal structure sustained by accretional heating. Our results predict that a growing Mars possibly acquired a massive and hot hybrid-type proto-atmosphere with surface pressure and temperature greater than several kbar and 2000 K, respectively, which is sufficient to produce a deep magma ocean. In such a high-temperature and high-pressure environment, a significant amount of H2O, CH4, CO, and H2is expected to be partitioned into the planetary interior, although this would strongly depend on the dynamics of the magma ocean and mantle solidification. The dissolved H2O may explain the wet Martian mantle implied from basaltic Martian meteorites. Along with the remnant reduced atmosphere after the hydrodynamic atmospheric escape, dissolved reduced gas species may have maintained an earliest Martian surface environment that allowed prebiotic chemical evolution and liquid H2O activities.
影响因子：
18.3
作者：
P. Rosenblatt;S. Charnoz;K. Dunseath;M. Terao-Dunseath;A. Trinh;R. Hyodo;H. Genda;Stéven Toupin
通讯作者：
P. Rosenblatt;S. Charnoz;K. Dunseath;M. Terao-Dunseath;A. Trinh;R. Hyodo;H. Genda;Stéven Toupin
影响因子：
4.9
作者：
Ikoma, Masahiro;Genda, Hidenori
通讯作者：
Genda, Hidenori