Spectral evolution of Iridium satellites recorded by AMOS spectral camera system

Abstract Spectroscopy of artificial space objects is a method utilised to retrieve the reflectance spectra of satellites, providing valuable information about the surface properties and material composition of objects. However, the reflectance spectrum of an object tends to slightly change over time, in a way that implies the surface shifting to redder colour hues and darkening overall. The causes of this reddening effect are up to this day unknown, although the leading explanation is the deterioration of surface materials due to exposure to the harsh environment of space. Large satellite constellations are ideal for the analysis of this effect. The studied data were obtained by AMOS - All-Sky Meteor Orbit System - developed by the Comenius University in Bratislava, Slovakia. Specular glints of Iridium satellites recorded over the course of six years are analysed to provide further insight into the explanation of the reddening effect.