Krypton isotopes and noble gas abundances in the coma of comet 67P/Churyumov-Gerasimenko

Martin Rubin (1) , Kathrin Altwegg (1, 2) , Hans Balsiger (1) , Akiva Bar-Nun (3) , Jean-Jacques Berthelier (4) , Christelle Briois (5) , Urs Calmonte (1) , Michael Combi (6) , Johan de Keyser (7) , Björn Fiethe (8) , Stephen Fuselier (9, 10) , Sébastien Gasc (1) , Tamas I. Gombosi (6) , Kenneth C. Hansen (6) , Ernest Kopp (1) , Axel Korth (11) , Diana Laufer (12) , Léna Le Roy (1) , Urs Mall (11) , Bernard Marty (13) , Olivier Mousis (14) , Tobias Owen (15) , Henri Rème (16) , Thierry Sémon (1) , Chia-Yu Tzou (1) , Jack Waite (8) , Peter Wurz (2, 1)

1 Physikalisches Institut [Bern]
2 CSH - Center for Space and Habitability
3 TAU - Department of Geophysics [Tel Aviv]
4 HELIOS - LATMOS
5 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
6 CLaSP - Department of Climate and Space Sciences and Engineering
7 BIRA-IASB - Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique
8 IDA - Institute of Computer and Network Engineering [Braunschweig]
9 Space Science and Engineering Division [San Antonio]
10 UTSA - The University of Texas at San Antonio
11 MPS - Max-Planck-Institut für Sonnensystemforschung
12 TAU - Department of Geophysical, Atmospheric and Planetary Sciences [Tel Aviv]
13 CRPG - Centre de Recherches Pétrographiques et Géochimiques
14 LAM - Laboratoire d'Astrophysique de Marseille
15 Institute for Astronomy [Honolulu]
16 IRAP - Institut de recherche en astrophysique et planétologie

The ROSINA mass spectrometer DFMS on board ESA's Rosetta spacecraft detected the major isotopes of the noble gases argon, krypton, and xenon in the coma of comet 67P/Churyumov-Gerasimenko. Earlier, it has been shown that xenon exhibits an isotopic composition distinct from anywhere else in the solar system. However, argon isotopes, within error, were shown to be consistent with solar isotope abundances. This discrepancy suggested an additional exotic component of xenon in comet 67P/Churyumov-Gerasimenko. Here we show that also krypton exhibits an isotopic composition close to solar. Furthermore, we found a depletion compared to solar of argon with respect to krypton and of krypton with respect to xenon, which is a necessity to postulate an addition of exotic xenon in the comet.

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]

Martin Rubin, Kathrin Altwegg, Hans Balsiger, Akiva Bar-Nun, Jean-Jacques Berthelier, et al.. Krypton isotopes and noble gas abundances in the coma of comet 67P/Churyumov-Gerasimenko. Science Advances , 2018, 4 (7), pp.eaar6297. ⟨10.1126/sciadv.aar6297⟩. ⟨insu-01877545⟩