Production and Reactions of Organic Molecules in Clouds of Venus
Jan Špaček, Paul B. Rimmer, Gage E. Owens, Spencer R. Cady, Daisy Sharma, Steven A. Benner
Abstract
High Resolution Image Download MS PowerPoint Slide For half a century, the possibility of organic molecules in sulfuric acid droplets in the clouds above Venus has been largely discounted. Here, we report the first results from an experimental exploration of this possibility, of primary interest to astronomers but also uncovering reactions that are remarkable to organic chemistry. This work provides a detailed mechanism of how small organic molecules might be generated in the sulfuric acid (H 2 SO 4 ) aerosol droplets that form the clouds above Venus, starting from formaldehyde (HCHO), a simple one carbon species produced photochemically in the gas phase. Laboratory 13 C and 1 H nuclear magnetic resonance studies detail processes by which dissolved HCHO reacts with dissolved carbon monoxide (CO) to produce a two-carbon organic species, glycolic acid (HOCH 2 COOH). They show that glycolic acid is surprisingly stable, for days or longer, depending on temperature, in concentrated H 2 SO 4 . However, glycolic acid slowly reacts further to give higher molecular weight organic materials, including colored and fluorescent species. These may contribute to the UV and visible light astronomy of Venus, and are guiding the design of an autofluorescence nephelometer scheduled to fly on a Rocket Lab mission to Venus in 2025.