Fig. (1).
Absorption cross-sections (cm2 molecule-1) in the far ultraviolet for some atmospheric molecules suggested for the prebiotic Earth. The cross-section data were compiled using the MPI-Mainz-UV-VIS Spectral Atlas of Gaseous Molecules (www.atmosphere.mpg.de/spectral-atlas-mainz), and sourced from the indicated references [157-165]. The dissociation thresholds – wavelengths below which photodissociation will occur – for CO and N2 are 104 and 100 nm, respectively, and thus these molecules are not included on this graph. The solar spectrum represents the irradiation at the top of the current Earth atmosphere (~600 km) [166].