Seasonal colors cycling on 67P/CG nucleus and coma

Abstract

Understanding how comets work is one of the more compelling questions to which Rosetta mission is trying to answer to. In this perspective, we investigate the temporal evolution of 67P/CG nucleus surface and dust particles with the scope to quantify the spectral changes occurring at different heliocentric distances, to search for possible correlations among them and to verify their dependence with activity. A quantitative analysis of seasonal Color changes occurring in the coma and nucleus of 67P/CG has been conducted by means of a systematic processing of the entire RosettaVIRTIS-M-VIS [1] channel dataset. Specific spectral indicators have been separately computed for the coma and the nucleus and then ordered in time-series spanning from January 2015 (in-bound orbit, heliocentric distance 2.55 AU), encompassing perihelion passage (August 2015, 1.24 AU) up to May 2016 (outbound orbit, 2.92 AU).