67P/Churyumov-Gerasimenko Spectrophotometric Properties
Abstract:On August 6th 2014, the Rosetta spacecraft entered orbit around the nucleus of comet 67P/Churyumov-Gerasimenko. During its approach, the Optical Spectroscopic and Infrared Remote Imaging System (OSIRIS) observed the nucleus with various illumination conditions and filters to characterize the surface. Observations with resolution of the order of 1m/pixel are scheduled before the end of the year 2014; they will provide incredible detail of the cometary nucleus’s surface. The mineralogical and photometric properties of the surface are very important scientific topics to understand the properties of the nucleus, the formation and evolution of its surface, and its relationship with the activity of the comet
Here we will present the results of the spectrophotometry obtained with 11 filters covering the 250-1000 nm range (obtained through the Narrow Angle Camera NAC), and of the photometric analysis of the surface of the cometary nucleus taken between July and November 2014. Images span various phase angles (including opposition) and various resolutions, and cover the entire surface of the nucleus. These observations will allow the first global and detailed spectrophotometric characterization of a comet nucleus. Of particular interest is the identification of ices on the surface or not, the mineralogical differences between the two lobes of the nucleus if any, and the global photometric properties.