Triton: Stratospheric molecules and organic sediments

• Published in: Geophysical research letters Vol. 16; no. 8; pp. 981 - 984
• Main Authors: Thompson, W. Reid, Singh, Sushil K., Khare, B. N., Sagan, Carl
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Blackwell Publishing Ltd 01.08.1989; American Geophysical Union
• Subjects: Astronomy; Atmosphere - chemistry; Charged particles; Condensates; Earth, ocean, space; Electrons; Exact sciences and technology; Extraterrestrial Environment; Geophysics; Haze; Hydrocarbons - analysis; Hydrogen Cyanide - analysis; Lunar And Planetary Exploration; Methane - analysis; Models, Chemical; Neptune; Nitriles - analysis; Photochemistry; Planets, their satellites and rings. Asteroids; Sediments; Solar system; Spectrophotometry, Infrared - methods; Stratosphere; Triton; Ultraviolet; Ultraviolet Rays; Methane; Neptune satellite; Laboratory study; Nitrile; Hydrocarbon; Stratosphere; Abundance; Experimental study; Planetary atmosphere; Nitrogen Molecules; Organic molecule; Chemical composition; Upper atmosphere; NASA Discipline Exobiology; Non-NASA Center
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/GL016i008p00981

Continuous-flow plasma discharge techniques show production rates of hydrocarbons and nitriles in N2 + CH4 atmospheres appropriate to the stratosphere of Titan, and indicate that a simple eddy diffusion model together with the observed electron flux quantitatively matches the Voyager IRIS observations for all the hydrocarbons, except for the simplest ones. Charged particle chemistry is very important in Triton's stratosphere. In the more CH4-rich case of Titan, many hydrocarbons and nitriles are produced in high yield. If N2 is present, the CH4 fraction is low, but hydrocarbons and nitriles are produced in fair yield, abundances of HCN and C2H2 in Triton's stratosphere exceed 10 to the 19th molecules/sq cm per sec, and NCCN, C3H4, and other species are predicted to be present. These molecules may be detected by IRIS if the stratosphere is as warm as expected. Both organic haze and condensed gases will provide a substantial UV and visible opacity in Triton's atmosphere.