First Far-Ultraviolet Observations of a Comet Nucleus: Rosetta-Alice Reflectance Spectroscopy of 67P/Churyumov-Gerasimenko

The Alice ultraviolet spectrograph aboard the ESA/NASA Rosetta mission is now orbiting comet 67P/Churyumov-Gerasimenko (C-G). Alice is an imaging spectrograph that operates from 700-2050 Å with a characteristic filled-slit resolution near 10 Å. On approach to and now in orbit with 67P/C-G, Alice has obtained numerous reflectance spectra of the cometary nucleus. These are the first reflectance spectra below 2000 Å of any cometary nucleus. We observe a very dark FUV surface with no strong H2O absorption band. We will describe the spatially-unresolved but rotationally-resolved spectra we have obtained, analyzing them for albedo and albedo slope, as well as spectral absorption features.