Noble gases may have come to Earth via comets
DOI: 10.1063/PT.5.029673
Science News : It has long been thought that asteroids and comets brought to Earth much of the raw material needed for life, such as water, carbon, nitrogen, and noble gases. But which brought what has been a matter of debate. Scientists last year proposed that it was more likely that asteroids were responsible for most of Earth’s water. However, comets may have brought other chemicals. Now, based on data provided by the Rosetta spacecraft, Bernard Marty of France’s Petrographic and Geochemical Research Center and colleagues say they have found evidence of argon in the atmosphere of comet 67P/Churyumov–Gerasimenko. Furthermore, the researchers say that judging by the composition of meteorites, “the amount of prebiotic material delivered by comets could have been quite considerable—equivalent to the present-day mass of the biosphere.”