Authors: G.C. Stevens, R.M. Clarke, E.J. Hart The gamma-ray and electron pulse irradiation of aqueous methane and some ethane solutions is reported. The ab- sorption spectra of the CH3 and C2H5 free radicals have been measured in the wavelength range 210-270 nm. At 210 nm e(CH3) = 850 M-1 cm-1 and e(C2Hs) = 520 M-1 cm-1. The bimolecular recombination rate…
Authors: L. Zhou, S. Maity, M. Abplanalp, A. Turner, R.I. Kaiser The chemical processing of ethylene ices (C2H4) by energetic electrons was investigated at 11 K to simulate the energy transfer processes and synthesis of new molecules induced by secondary electrons generated in the track of galactic cosmic ray particles. A combination of Fourier transform infrared spectrometry (solid state) and…
Authors: T. Gautier, N. Carrasco, A. Buch, C. Szopa, E. Sciamma-O’Brien, G. Cernogora, This work presents the first study of the gaseous products resulting from the partial dissociation of meth- ane and nitrogen in the PAMPRE experimental setup simulating Titan’s atmospheric chemistry. Using cryogenic trapping, the gaseous products generated from the chemical reactions occurring in the reactor have been trapped….
Authors: M. Ferus, P. Kubelík, A. Knízek, A. Pastorek, J. Sutherland, S. Civiš Recent results in prebiotic chemistry implicate hydrogen cyanide (HCN) as the source of carbon and nitrogen for the synthesis of nucleotide, amino acid and lipid building blocks. HCN can be produced during impact events by reprocessing of carbonaceous and nitrogenous materials from both the impactor and the…
Authors: M. Civiš, M. Ferus, A. Knížek, P. Kubelik, M. Kamas, P. Španel, K. Drahina, V. Shestivska, L. Juha, P. Skrehot, V. Laitl, S. Civiš Large-scale plasma was created in gas mixtures containing methane using high-power laser-induced dielectric breakdown (LIDB). The composition of the mixtures corresponded to a cometary and/or meteoritic impact into the early atmosphere of either Titan or…
Authors: J. H. Baxendale, R.D. Sedgwick The yields of hydrogen, formaldehyde, ethylene glycol, methane and carbon monoxide from the radiolysis of methanol vapour have been measured and also those of H2 and HD from CH3OD. These have been correlated with the ions observed in the mass spectra. Benzene decreases the yields of hydrogen and formaldehyde and the effect is attributed…
Authors: L. M. Lara The vertical distribution of Titan’s neutral atmosphere compounds is calculated from a new photochemical model extending from 40 to 1432 km. This model makes use of many updated reaction rates, and of the new scheme for methane photolysis proposed by Mordauntet al. [1993].The model also includes a realistic treatment of the dissociation of N2, of the…
The photochemistries of methane and HCN are discussed in the context of the primitive terrestrial atmosphere,using a detailed numerical model. In the absenceof abundant O2, absorption of solar EUV (λ < 1023Å) by N2 provides a large thermosphersic source of atomic nitrogen. Methane is oxidized cleanly and efficiently,provided CO2 is more abundant than CH,•. Otherwise,a large fraction of the methane…