Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
Department of Geosciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel.
Science. 2015 Jan 23;347(6220):1261952. doi: 10.1126/science.1261952. Epub 2014 Dec 10.
The provenance of water and organic compounds on Earth and other terrestrial planets has been discussed for a long time without reaching a consensus. One of the best means to distinguish between different scenarios is by determining the deuterium-to-hydrogen (D/H) ratios in the reservoirs for comets and Earth's oceans. Here, we report the direct in situ measurement of the D/H ratio in the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA mass spectrometer aboard the European Space Agency's Rosetta spacecraft, which is found to be (5.3 ± 0.7) × 10(-4)—that is, approximately three times the terrestrial value. Previous cometary measurements and our new finding suggest a wide range of D/H ratios in the water within Jupiter family objects and preclude the idea that this reservoir is solely composed of Earth ocean-like water.
地球和其他类地行星上水和有机化合物的起源长期以来一直存在争议，尚未达成共识。区分不同情况的最佳方法之一是确定彗星和地球海洋中储层的氘氢（D/H）比值。在这里，我们报告了通过欧洲航天局罗塞塔号飞船上的 ROSINA 质谱仪对木星家族彗星 67P/楚留莫夫-格拉希门克的 D/H 比值的直接原位测量，发现其值为（5.3 ± 0.7）×10（-4），即大约是地球值的三倍。以前的彗星测量和我们的新发现表明木星家族物体中水的 D/H 比值范围很广，排除了该储层仅由类似地球海洋的水组成的想法。
