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

Marty B; Altwegg K; Balsiger H; Bar-Nun A; Bekaert DV; Berthelier JJ; Bieler A; Briois C; Calmonte U; Combi M; De Keyser J; Fiethe B; Fuselier SA; Gasc S; Gombosi TI; Hansen KC; Hassig M; Jackel A; Kopp E; Korth A; Le Roy L; Mall U; Mousis O; Owen T; Reme H; Rubin M; Semon T; Tzou CY; Waite JH; Wurz P

Science, Vol.356, No.6342, 1069-+, 2017

DOI10.1126/science.aal3496 Export Citation

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

Marty B, Altwegg K, Balsiger H, Bar-Nun A, Bekaert DV, Berthelier JJ, Bieler A, Briois C, Calmonte U, Combi M, De Keyser J, Fiethe B, Fuselier SA, Gasc S, Gombosi TI, Hansen KC, Hassig M, Jackel A, Kopp E, Korth A, Le Roy L, Mall U, Mousis O, Owen T, Reme H, Rubin M, Semon T, Tzou CY, Waite JH, Wurz P

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.