67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio
Abstract
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.
- Publication:
-
Science
- Pub Date:
- January 2015
- DOI:
- 10.1126/science.1261952
- Bibcode:
- 2015Sci...347A.387A
- Keywords:
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- ASTRONOMY, PLANET SCI, ONLINE