Plasma discharge in N2 + CH4 at low pressures: Experimental results and applications to Titan

Optical properties of poly-HCN and their astronomical applications

“…A number of these compounds are not present in poly-HCN and would not be expected to be released on volatilization of poly-HCN. In addition, of course, it makes intuitive sense that the organic solid generated by irradiation of simulated Titanian atmospheres, experiments that successfully and quantitatively reproduce the gas-phase organics in Titan's atmosphere (63), should be the best candidate for the organic haze of Titan (60).…”

Laboratory investigation on the formation of unsaturated nitriles in Titan’s atmosphere

“…Prior to the Voyager encounters in 1980 and 1981, star occultation and terrestrial based telescopes identi®ed primarily molecular nitrogen, N 2 (90%), and trace gases methane (CH 4 ) (Karkoschka, 1994;Lunine et al, 1998), ethane (C 2 H 6 ), and acetylene (C 2 H 2 ) in Titan's stratosphere (Thompson et al, 1991). The Voyager missions to Titan opened a new chapter in solar system exploration and extraterrestrial atmospheric chemistry.…”

“…The longer wavelength photons, however, can penetrate down to the stratosphere to photodissociate molecules; hence the chemistry in these atmospheric regions is expected to be driven by neutral± neutral chemistry of photochemically generated radicals with neutral species (Seki et al, 1996;Lellouch, 1990;Lorenz et al, 1997). To simulate this chemistry of Titan's atmosphere in terrestrial laboratories and reproduce the chemical composition as observed in Titan, a multitude of discharge studies, photochemical experiments employing complex gas mixtures, as well as electron bombardments of gaseous targets have been performed, leading to the synthesis of a great variety of nitriles CH 3 CN, C 2 H 3 CN, CH 3 CCCN and unsaturated hydrocarbons C 2 H 3 C 2 H 3 , H 2 CCCH 2 , C 2 H 3 CCH, and C 3 H 6 , see for example Thompson et al (1991), Nascimento et al (1998), and references therein. Based on the dominance of atmospheric N 2 , and CH 4 , most experimentalists and modelers postulate Titan's chemistry to be dominated by N( 2 D), CH 2 , and CH reactions (Tanguy et al, 1990;Raulin et al, 1998 and references therein; Lara et al, 1991).…”

Organic environments on Saturn’s moon, Titan: Simulating chemical reactions and analyzing products by FT-ICR and ion-trap mass spectrometry

“…T itan, the largest of Saturn's moons, is known to possess a rich organic environment of important relevance to astrobiology, prebiotic earth chemistry, and the origin of life, since the organics have been protected from damaging particles and UV radiation owing to a thick atmosphere. Many small organic compounds have been detected in Titan's upper atmosphere as a result of Voyager [1][2][3][4][5][6][7][8] and subsequent modeling studies [9,10] of the organic and atmospheric haze chemistry are resulting in a refined picture of this complex CHN laboratory. Beginning in 2005, we should have a refined global inventory of low molecular weight organic molecules present in the atmosphere as well as some secondary information regarding higher mass organic aerosols presented to the surface of Titan as a result of the Cassini-Huygens mission [11,12].…”