The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars
The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars
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DOI：
10.1126/science.1260291
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发表时间：
2015-01-23
期刊：
影响因子：
56.9
通讯作者：
Wray, J. J.
中科院分区：
文献类型：
--
作者：
Mahaffy, P. R.;Webster, C. R.;Wray, J. J.
在古代火星粘土中，强结合水或羟基中的氘氢比（D/H）保留了这些矿物形成水的印记。Curtain的火星样品分析（SAM）实验测量了从西方时代盖尔陨石坑蒙皂石样品中在550摄氏度至950摄氏度之间释放的热演化水和氢气，以确定这种同位素比率。D/H值是标准平均海水中比值的3.0（+/- 0.2）倍。这个类似于30亿年前的泥岩中的D/H比，是现在火星大气的一半，但大大高于早期火星的预期，表明地球的氢逃逸和干燥的历史很长。
The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550 degrees and 950 degrees C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (+/- 0.2) times the ratio in standard mean ocean water. The D/H ratio in this similar to 3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.