High-Time Resolution In-situ Investigation of Major Cometary Volatiles around 67P/C-G at 3.1 - 2.3 AU Measured with ROSINA-RTOF

Cometsconsidered to be pristine objects contain key information about the early formation of the solar system. Their volatile components can provide clues about the origin and evolution of gases and ices in the comets. Measurements with ROSINA/RTOF at 67P/Churyumov-Gerasimenko have now allowed, for the first time, a direct in situ high-time resolution measurement of the most abundant cometary molecules originating directly from a comet's nucleus over a long time-period, much longer than any previous measurements at a close distance to a cometbetween 3.1 and 2.3 au. We determine the local densities of H 2 O, CO 2 , and CO, and investigate their variabilities.