Type:		Journal, Article
Title:		67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio
Author(s):		Altwegg, K.; Balsiger, H.; Bar-Nun, A.; Berthelier, J. J.; Bieler, A.; Bochsler, P.; Briois, C.; Calmonte, U.; Combi, M.; De Keyser, J.; Eberhardt, P.; Fiethe, B.; Fuselier, S.; Gasc, S.; Gombosi, T. I.; Hansen, K.; Hässig, M.; Jäckel, A.; Kopp, E.; Korth, A.; LeRoy, L.; Mall, U.; Marty, B.; Mousis, O.; Neefs, E.; Owen, T.; Rème, H.; Rubin, M.; Sémon, T.; Tzou, C.; Waite, H.; Wurz, P.
Date:		2015/01/23
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.
Publisher:		American Association for the Advancement of Science
Journal (full):		Science
Volume:		347
Issue:		6220
Start Page:		1261952
Link:		http://science.sciencemag.org/content/347/6220/1261952.abstract
Link (PDF):		http://science.sciencemag.org/content/sci/347/6220/1261952.full.pdf