Water and carbon dioxide production in 67P/Churyumov-Gerasimenko: comparison with VIRTIS-M observations

International audienceThe VIRTIS spectrometer on the Rosetta mission performed infrared observations of the coma of the comet 67P/Churyumov-Gerasimenko, detecting water and carbon dioxide emissions. Through the use of a thermophysical model, we are willing to see if the different behaviour of water and carbon dioxide outgassing above the surface, seen in the VIRTIS data, might be indicative of a different thermal history of the northern and southern hemispheres of 67P or reflects instead a primordial compositional difference. Preliminary analysis suggest that the internal composition is quite homogeneous, and that the differences observed by VIRTIS and other instruments can be interpreted and reproduced by considering the thermal and illumination history of the comet along its orbit