The UV signature of carbon in the solar system

摘要: Carbon compounds are ubiquitous in the solar system but challenging to study using remote sensing due mostly bland spectral nature of these species traditional visible-near-infrared regime. In contrast, carbonaceous spectrally active ultraviolet (UV) have largely not been considered for studies surfaces. We compile existing UV data carbon compounds—well-studied contemplation ISM extinction “bump”—to review trends behavior. Thermal and/or irradiation processing results loss H and ultimately graphitization. Graphitization is shown produce distinct features UV, which predicted be more readily detected inner system, whereas outer bodies expected dominated by less-processed compounds. Throughout we can thus consider a “carbon continuum” where evolved carbons exhibit stronger absorption feature associated far-UV rise. compare models with spacecraft two from different points continuum, Ceres Iapetus. find that apparent strong upturn Ceres’ spectrum (in 150–200 nm range) explained an anthracite-like while Iapetus’ reflectance peak consistent polycyclic aromatic hydrocarbons. make generalized predictions characteristics other regions system.