title: Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature.
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.
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. martin.rubin@space.unibe.ch.
authors: M
authors: M
authors: Rubin
authors: 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.
authors: K
authors: K
authors: Altwegg
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: H
authors: H
authors: Balsiger
authors: Department of Geoscience, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel.
authors: A
authors: A
authors: Bar-Nun
authors: Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS)/Institute Pierre Simon Laplace-CNRS-UPMC-UVSQ, 4 Avenue de Neptune F-94100, Saint-Maur, France.
authors: J-J
authors: JJ
authors: Berthelier
authors: 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.
authors: A
authors: A
authors: Bieler
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: P
authors: P
authors: Bochsler
authors: Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), UMR 6115 CNRS-Université d'Orléans, Orléans, France.
authors: C
authors: C
authors: Briois
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: U
authors: U
authors: Calmonte
authors: Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA.
authors: M
authors: M
authors: Combi
authors: Belgian Institute for Space Aeronomy, Belgisch Instituut voor Ruimte-Aeronomie-Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Ringlaan 3, B-1180 Brussels, Belgium.
authors: J
authors: J
authors: De Keyser
authors: Belgian Institute for Space Aeronomy, Belgisch Instituut voor Ruimte-Aeronomie-Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Ringlaan 3, B-1180 Brussels, Belgium.
authors: F
authors: F
authors: Dhooghe
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: P
authors: P
authors: Eberhardt
authors: Institute of Computer and Network Engineering, Technische Universität Braunschweig, Hans-Sommer-Straße 66, D-38106 Braunschweig, Germany.
authors: B
authors: B
authors: Fiethe
authors: Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA.
authors: S A
authors: SA
authors: Fuselier
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: S
authors: S
authors: Gasc
authors: Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA.
authors: T I
authors: TI
authors: Gombosi
authors: Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA.
authors: K C
authors: KC
authors: Hansen
authors: 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.
authors: M
authors: M
authors: Hässig
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: A
authors: A
authors: Jäckel
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: E
authors: E
authors: Kopp
authors: Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany.
authors: A
authors: A
authors: Korth
authors: Center for Space and Habitability, University of Bern, Sidlerstrasse. 5, CH-3012 Bern, Switzerland.
authors: L
authors: L
authors: Le Roy
authors: Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany.
authors: U
authors: U
authors: Mall
authors: 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.
authors: B
authors: B
authors: Marty
authors: Aix Marseille Université, CNRS, Laboratoire d'Astrophysique de Marseille UMR 7326, 13388, Marseille, France.
authors: O
authors: O
authors: Mousis
authors: Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA.
authors: T
authors: T
authors: Owen
authors: 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.
authors: H
authors: H
authors: Rème
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: T
authors: T
authors: Sémon
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: C-Y
authors: CY
authors: Tzou
authors: Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA.
authors: J H
authors: JH
authors: Waite
authors: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
authors: P
authors: P
authors: Wurz