Science. 2015 Jan 23;347(6220):1261952. doi: 10.1126/science.1261952. Epub 2014 Dec 10.

Cometary science. 67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio.

Altwegg K¹, Balsiger H², Bar-Nun A³, Berthelier JJ⁴, Bieler A⁵, Bochsler P², Briois C⁶, Calmonte U², Combi M⁷, De Keyser J⁸, Eberhardt P², Fiethe B⁹, Fuselier S¹⁰, Gasc S², Gombosi TI⁷, Hansen KC⁷, Hässig M¹¹, Jäckel A², Kopp E², Korth A¹², LeRoy L², Mall U¹², Marty B¹³, Mousis O¹⁴, Neefs E⁸, Owen T¹⁵, Rème H¹⁶, Rubin M², Sémon T², Tzou CY², Waite H¹⁰, Wurz P².

Author information

1: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. altwegg@space.unibe.ch.
2: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
3: Department of Geosciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel.
4: Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 4 Avenue de Neptune, F-94100 Saint-Maur, France.
5: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA.
6: Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), UMR 6115 CNRS-Université d'Orléans, France.
7: Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA.
8: Space Physics Division, Belgisch Instituut voor Ruimte-Aëronomie (BIRA)-Institut d'Aéronomie Spatiale de Belgique (IASB), Ringlaan 3, B-1180 Brussels, Belgium.
9: Institute of Computer and Network Engineering (IDA), Technicsche Universität Braunschweig, Hans-Sommer-Straße 66, D-38106 Braunschweig, Germany.
10: Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA.
11: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA.
12: Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany.
13: Centre de Recherches Pétrographiques et Géochimiques, Centre de Recherches Pétrographiques et Géochimiques (CRPG)-CNRS, Université de Lorraine, 15 rue Notre Dame des Pauvres, BP 20, 54501 Vandoeuvre lès Nancy, France.
14: Université de Franche-Comté, Institut Univers, Transport, Interfaces, Nanostructures, Atmosphère et Environnement, Molécules (UTINAM), CNRS/Institut National des Sciences de l'Univers (INSU), UMR 6213 Besançon Cedex, France.
15: Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA.
16: Université de Toulouse, Université Paul Sabatier (UPS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. CNRS, IRAP, 9 Avenue du Colonel Roche, BP 44346, F-31028 Toulouse cedex 4, France.

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.