Composition of terrestrial exoplanet atmospheres from meteorite outgassing experiments
Composition of terrestrial exoplanet atmospheres from meteorite outgassing experiments
复制标题
陨石释气实验中的类地系外行星大气成分
作者：
M. Thompson;M. Telus;L. Schaefer;J. Fortney;T. Joshi;D. Lederman
类地系外行星可能通过吸积过程中和吸积后的放气形成初始大气，尽管目前还没有关于如何将行星的整体成分与其早期大气特性联系起来的第一原理理解。通过分析陨石可以获得对这种联系的重要见解，陨石是行星构建块的代表性样本。我们进行实验室除气实验，使用质谱仪测量陨石样品加热至 1,200°C 时释放的挥发物的丰度。我们发现，三个碳质球粒陨石样品的排气持续产生富含 H2O（平均约 66%）的大气，但含有大量的 CO（约 18%）和 CO2（约 15%）以及少量的 H2 和 H2S（高达 1%）。这些结果为类地行星大气理论模型中的初始化学成分提供了实验约束，并提供了主要气体种类随温度变化的丰度。实验室进行了将陨石加热至 1,200°C 的实验，以了解系外行星内部的排气情况。与模型通常使用的假设有很大不同，实验表明类地行星将形成富含水的蒸汽大气，并含有大量的二氧化碳和二氧化碳。
Terrestrial exoplanets likely form initial atmospheres through outgassing during and after accretion, although there is currently no first-principles understanding of how to connect a planet’s bulk composition to its early atmospheric properties. Important insights into this connection can be gained by assaying meteorites, which are representative samples of planetary building blocks. We perform laboratory outgassing experiments that use a mass spectrometer to measure the abundances of volatiles released when meteorite samples are heated to 1,200 °C. We find that outgassing from three carbonaceous chondrite samples consistently produce H2O-rich (average of ~66%) atmospheres but with substantial amounts of CO (~18%) and CO2 (~15%) as well as smaller quantities of H2 and H2S (up to 1%). These results provide experimental constraints on the initial chemical composition in theoretical models of terrestrial planet atmospheres, and supply abundances for principal gas species as a function of temperature. Laboratory experiments where meteorites are heated up to 1,200 °C are performed in order to inform on the outgassing from exoplanetary interiors. Differing considerably from assumptions commonly used by models, the experiments indicate that terrestrial planets would form water-rich steam atmospheres with substantial amounts of CO2 and CO.
研究微陨石烧蚀产生的甲烷对火星大气的贡献
影响因子：
5.3
作者：
Court R
通讯作者：
Court R
影响因子：
5
作者：
R. Court;M. Sephton
通讯作者：
R. Court;M. Sephton
岩石行星和星子上除气的初始大气的氧化还原状态
DOI：
10.3847/1538-4357/aa784f
发表时间：
2017
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Schaefer, Laura;Fegley, Bruce
通讯作者：
Fegley, Bruce