The difficult yet successful measurement of several isotopes of the noble gas xenon on comet 67P/Churyumov-Gerasimenko using the Bernese instrument ROSINA on the Rosetta probe shows that materials arrived on Earth due to comet impacts. As proven by further Bern measurements of silicon isotopes, in the beginning our solar system was extremely heterogeneous. The high amount of so-called “heavy” water also shows that cometary ice is older than our solar system.