Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature

M Rubin; K Altwegg; H Balsiger; A Bar-Nun; J-J Berthelier; A Bieler; P Bochsler; C Briois; U Calmonte; M Combi; J De Keyser; F Dhooghe; P Eberhardt; B Fiethe; S A Fuselier; S Gasc; T I Gombosi; K C Hansen; M Hässig; A Jäckel; E Kopp; A Korth; L Le Roy; U Mall; B Marty; O Mousis; T Owen; H Rème; T Sémon; C-Y Tzou; J H Waite; P Wurz

doi:10.1126/science.aaa6100

Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature

Science. 2015 Apr 10;348(6231):232-5. doi: 10.1126/science.aaa6100. Epub 2015 Mar 19.

Authors

M Rubin¹, K Altwegg², H Balsiger³, A Bar-Nun⁴, J-J Berthelier⁵, A Bieler⁶, P Bochsler³, C Briois⁷, U Calmonte³, M Combi⁸, J De Keyser⁹, F Dhooghe⁹, P Eberhardt³, B Fiethe¹⁰, S A Fuselier¹¹, S Gasc³, T I Gombosi⁸, K C Hansen⁸, M Hässig¹², A Jäckel³, E Kopp³, A Korth¹³, L Le Roy¹⁴, U Mall¹³, B Marty¹⁵, O Mousis¹⁶, T Owen¹⁷, H Rème¹⁸, T Sémon³, C-Y Tzou³, J H Waite¹¹, P Wurz³

Affiliations

¹ Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. martin.rubin@space.unibe.ch.
² Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Center for Space and Habitability, University of Bern, Sidlerstrasse. 5, CH-3012 Bern, Switzerland.
³ Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
⁴ Department of Geoscience, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel.
⁵ Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS)/Institute Pierre Simon Laplace-CNRS-UPMC-UVSQ, 4 Avenue de Neptune F-94100, Saint-Maur, France.
⁶ 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.
⁷ Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), UMR 6115 CNRS-Université d'Orléans, Orléans, France.
⁸ Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA.
⁹ Belgian Institute for Space Aeronomy, Belgisch Instituut voor Ruimte-Aeronomie-Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Ringlaan 3, B-1180 Brussels, Belgium.
¹⁰ Institute of Computer and Network Engineering, Technische Universität Braunschweig, Hans-Sommer-Straße 66, D-38106 Braunschweig, Germany.
¹¹ Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA.
¹² 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.
¹³ Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany.
¹⁴ Center for Space and Habitability, University of Bern, Sidlerstrasse. 5, CH-3012 Bern, Switzerland.
¹⁵ Centre de Recherches Pétrographiques et Géochimiques (CRPG)-CNRS, Université de Lorraine, 15 rue Notre Dame des Pauvres, Bôite Postale 20, 54501 Vandoeuvre lès Nancy, France.
¹⁶ Aix Marseille Université, CNRS, Laboratoire d'Astrophysique de Marseille UMR 7326, 13388, Marseille, France.
¹⁷ Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA.
¹⁸ Université de Toulouse; UPS-OMP; Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. CNRS; IRAP; 9 Avenue du Colonel Roche, Boîte Postale 44346, F-31028 Toulouse Cedex 4, France.

PMID: 25791084
DOI: 10.1126/science.aaa6100

Abstract

Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system, N2 has not been detected. Here we report the direct in situ measurement of N2 in the Jupiter family comet 67P/Churyumov-Gerasimenko, made by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer aboard the Rosetta spacecraft. A N2/CO ratio of (5.70 ± 0.66) × 10(-3) (2σ standard deviation of the sampled mean) corresponds to depletion by a factor of ~25.4 ± 8.9 as compared to the protosolar value. This depletion suggests that cometary grains formed at low-temperature conditions below ~30 kelvin.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.