Xenon Isotopes in 67P/Churyumov-Gerasimenko Show That Comets Contributed to Earth's Atmosphere

Science. 2017 Jun 9;356(6342):1069-1072. doi: 10.1126/science.aal3496.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't