Hydrothermal processing of cometary volatiles--applications to Triton.
Hydrothermal processing of cometary volatiles--applications to Triton.
复制标题
彗星挥发物的水热处理——在海卫一上的应用。
DOI：
10.1006/icar.1993.1185
复制
发表时间：
1993
期刊：
影响因子：
3.2
通讯作者：
W. B. McKinnon
中科院分区：
文献类型：
--
作者：
E. Shock;W. B. McKinnon
在被海王星捕获后，海卫一可能经历了一次潮汐加热，足以融化其冰冷的地幔，也可能融化其岩石核心。这种加热会驱动核岩/地幔-海洋边界的热液循环。我们认为，这种热液后处理的海卫一的挥发性预算的化学后果，假设一个初始的彗星组成的冰冷的地幔，并评估温度和氧化态的变化的影响。我们认为后者可能是由岩石中的矿物组合所控制的。这种再处理可以解释海卫一大气中一氧化碳的缺乏，以及它相对于卫星表面冰中的N2和（显然）CO2的消耗。我们的计算还表明，无论氮的Triton，N2和/或NH3的原始来源可能是丰富的产品的水热后处理。取决于温度和主要氧化态，乙酸、乙醇、尿素、甲醇和乙胺除了氨之外，也可能是所得覆盖物材料的重要组分。因此，海卫一可能保存了可能导致早期陆地热液系统中生命起源的有机化学。
Subsequent to its capture by Neptune, Triton could have experienced an episode of tidal heating sufficient to melt its icy mantle and possibly its rocky core as well. This heating would have driven hydrothermal circulation at the core-rock/mantle-ocean boundary. We consider the chemical consequences of this hydrothermal reprocessing on Triton's volatile budget by assuming an initial cometary composition for the icy mantle and evaluating the effects of changes in temperature and oxidation state. We assume that the latter would have been controlled by mineral assemblages in the rock. Such reprocessing could explain the lack of carbon monoxide in the atmosphere of Triton and its depletion relative to N2 and (apparently) CO2 in the satellite's surface ices. Our calculations also show that whatever the original source of nitrogen in Triton, N2 and/or NH3 are likely abundant products of hydrothermal reprocessing. Depending on the temperature and prevailing oxidation state, acetic acid, ethanol, urea, methanol, and ethanamine are possible important components, in addition to ammonia, of the resulting mantle material. Triton may thus preserve the organic chemistry that might have led to the origin of life in early terrestrial hydrothermal systems.