Surface changes on the Imhotep region - interpretation of VIRTIS data with the help of a thermophysical model

The Rosetta mission and the huge amount of data on the comet 67P/CG has given us the opportunity to test and improve in an unprecedented way the models describing the thermophysical properties of cometary nuclei. Using this kind of models and comparing their results with the observations, it is possible to determine the properties of the nucleus surface and how they change with time, and to infer the conditions of the interior, shedding some light on the formation and evolution processes. In this talk the preliminary results will be shown of the interpretation of the surface temperatures derived from the VIRTIS spectrometer. With the help of the thermophysical model and using a feedback process it is possible to interpret the temperatures derived from VIRTIS spectra in order to determine the amount of ice that is present in the surface layers and its variation along the orbit. It is also possible, using the VIRTIS data, to infer other thermophysical properties of the surface such as the porosity and the roughness. The area on which this analysis has been performed is the Imhotep region, selected for its variety of different terrains and structures and the good and continuous coverage along the time of the mission.