NEXAFS spectra at the nitrogen K-edge of pure glycine (top), 15% glycine in water ice (bottom), before and at the end of the irradiation. On the right panels are shown the difference spectra (irradiated minus non irradiated), at selected doses; pure glycine 0.30; 0.91; 1.52; 2.54 equivalent time of solar irradiation (year); 15% glycine dilution 0.36; 1.0; 1.72 years. The red arrows indicate how the peaks grow when the irradiation proceeds.