Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth's atmosphere

B. Marty (1) , Kathrin Altwegg (2, 3) , Hans Balsiger (3) , A. Bar-Nun (4) , D.V. Bekaert (1) , Jean-Jacques Berthelier (5) , A. Bieler (3, 6) , Christelle Briois (7) , U. Calmonte (3) , M. Combi (8) , J. de Keyser (9) , B. Fiethe (10) , S. A. Fuselier (11) , S. Gasc (3) , Tamas I. Gombosi (8) , K. C. Hansen (8) , M. Hässig (3, 11) , A. Jäckel (3) , E. Kopp (3) , A. Korth (12) , Léna Le Roy (3) , U. Mall (12) , O. Mousis (13) , T. Owen (14) , H. Rème (15) , M. Rubin (3) , T. Sémon (3) , C.-Y. Tzou (3) , J. H. Waite (11) , P. Wurz (3)

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

The origin of cometary matter and the potential contribution of comets to inner-planet atmospheres are long-standing problems. During a series of dedicated low-altitude orbits, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) on the Rosetta spacecraft analyzed the isotopes of xenon in the coma of comet 67P/Churyumov-Gerasimenko. The xenon isotopic composition shows deficits in heavy xenon isotopes and matches that of a primordial atmospheric component. The present-day Earth atmosphere contains 22 ± 5% cometary xenon, in addition to chondritic (or solar) xenon.

Domains: Sciences of the Universe [physics]

B. Marty, Kathrin Altwegg, Hans Balsiger, A. Bar-Nun, D.V. Bekaert, et al.. Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth's atmosphere. Science, 2017, 356 (6342), pp.1069-1072. ⟨10.1126/science.aal3496⟩. ⟨insu-01670669⟩