New analysis shows how sulfur clouds may form in Venus’ atmosphere
Scientists using advanced computational chemistry techniques have found a new pathway for the formation of sulfur particles in Venus’ atmosphere. These results may help to understand the long-sought identity of the mysterious ultraviolet absorber on Venus.
“We know that Venus’ atmosphere contains abundant SO2 and sulfuric acid particles. We expect that ultraviolet destruction of SO2 produces sulfur particles. They are made up of atom S (sulphur) to S2dance4 and finally S8. But how is this process set in motion, that is, how does S . work?2 shape?” said Planetary Science Institute Senior Scientist James Lyons, an author at the nature communication paper “Photochemical and thermochemical routes to S2 and polysulfur formation in the atmosphere of Venus.”
One possibility is to use S. to shape2 of two sulfur atoms, i.e. reaction of S and S. Molecules of S2 and S2 can then combine to get S. to shape4, and so on. Sulfur particles can be formed by condensation of S8 or by condensation of S2s4 and other allotropes — various physical forms in which an element can exist — which then rearrange to form condensed S. to shape8.
“Sulphur particles, and the yellow sulfur we see more often, are mainly made up of S8, which has a ring structure. The ring structure makes S8 more stable to destruction by UV light than the other allotropes. S . to shape8we can either start with two S atoms and S . to make2or we can S . produce2 through a different route, which we did in the paper,” Lyons said.
“We have found a new way for S2 formation, the reaction of sulfur monoxide (SO) and sulfur monoxide (S2O), which is much faster than combining two S atoms to make S. to make2Lyons said.
“For the first time, we are using computational chemistry techniques to determine which reactions are most important, rather than waiting for lab measurements or using very imprecise estimates of the rate of unstudied reactions. This is a new and much needed approach for studying the atmosphere of Venus,” Lyons said. “People are reluctant to go to the lab to measure rate constants for molecules made up of S, chlorine (Cl), and oxygen (O) – these are difficult and sometimes dangerous compounds to work with. Calculation methods are the best – and really only alternative.
Calculation methods were used to calculate the rate constants and determine the expected reaction products. These are state-of-the-art computational models (what we call ab initio models). These ab initio calculations were made by the authors from Spain and the University of Pennsylvania.
“This research illustrates a different path to S2 and formation of sulfur particles. Sulfur chemistry is dominant in Venus’ atmosphere and most likely plays a key role in the formation of the enigmatic UV absorber. More broadly, this work opens the doors to using molecular ab initio techniques to unravel the complex chemistry of Venus,” Lyons said.
No signs of life on Venus (yet)
Antonio Francés-Monerris et al, Photochemical and thermochemical pathways to S2 and polysulfur formation in the atmosphere of Venus, nature communication (2022). DOI: 10.1038/s41467-022-32170-x
Quote: New analysis shows how sulfur clouds may form in Venus’ atmosphere (2022, August 9,), retrieved August 9, 2022 from https://phys.org/news/2022-08-analysis-sulphur-clouds-venus- atmosphere.html
This document is copyrighted. Other than fair dealing for personal study or research, nothing may be reproduced without written permission. The content is provided for informational purposes only.