Correlation between insolation model and boulder deposits on the 67P/Churymov-Gerasimeko comet

Comets are considered the most fascinating and changing primordial objects of our solar system. They are not yet well understood, but they conserve important informations about the origin, the formation and the evolution of the solar system and all of its objects. From these considerations is born Rosetta, the European Space Agency mission, lanched in 2004, with the aim of study the composition, the chemical properties, the activity and the behaviour approaching the Sun during its perihelion, of 67P/Churyumov-Gerasimenko comet. The images of this short-period comet was taken in particular from OSIRIS, an Optical, Spectroscopic and Infrared Remote Imaging System onboard Rosetta. It revealed that the comet is characterized by two main lobes connected by a small neck, and that the surface is a collection of contrast, such as smooth plains or high fractured terrains. Very important features on the comet surface are the boulder deposits, i.e. positive reliefs detectable in different images with the constant presence of elongated shadows whose extension depends on the illumination geometry, and that seem to be detached from the ground where they stands. These objects are scattered all over the surface and they can be found both isolated or in cluster. In this thesis will be calculate the incidence and emission angles on some regions of the comet, the same areas studied by recent work in which it was calculated the size-frequency distribution of boulders with diameters ≥ 7m. In particular, the solar incidence angle will be involved to compute the total amount of absorbed solar energy for these different regions. The results show a trend between a high value of irradiation and high level of fracturing, but not for all of the regions analyzed.