A mystery of sulphur clouds of Venus may be solved by new computer model
Computational methods can help us understand exotic chemical processes in planetary atmospheres.
Scientists using new computational methods have gained a new insight into the possible workings of Venus’s complex atmosphere.
Venus is enveloped in a thick cloud composed mostly of sulphuric acid. These clouds reflect most of the sunlight that shines on the planet, making it the brightest object in the sky after the Sun and the Moon. However, spacecraft and Earth-based observations have also detected the presence of an unknown UV absorber in the atmosphere.
A team of scientists now suggests, after the use of sophisticated computational modeling, a new route for making disulfur – within the clouds of Venus – an allotrope of sulfur that contains two sulfur atoms.
Disulfur leads to the formation of other sulphur allotropes and later, cyclic, or ring-structured, molecules of eight sulphur atoms within the atmosphere of Venus. These sulphur particles can absorb UV light.
The team proposes that sulphur dioxide (SO2) is broken down by sunlight to form sulphur monoxide (SO) and disulphur monoxide (S2O), providing a faster route to making disulphur than combining separate sulphur atoms. .
It is very useful to use computational methods in this context, as working with the chemicals and compounds found in the atmosphere of Venus, including sulphur, chlorine and oxygen, can be difficult and sometimes dangerous.
For the first time, we are using computational chemistry techniques to determine which reactions are most important, rather than waiting for laboratory measurements to be made or using grossly inaccurate estimates of the rates of unbiased reactions—James Lyons , senior scientist at the Planetary Science Institute and an author of the paper, said in a press statement (opens in new tab).
This is a new and much-needed approach to studying the atmosphere of Venus- Leon said.
Although there is no consensus yet on the identity of the absorber, it is believed to contain the sulphur chemical. Triatomic and tetratomic allotropes of sulphur, the latter also formed from disulphur, have been proposed to be mysterious UV absorbers.
The team, which also includes scientists from the Universitat de Valencia and the Institute of Physical Chemistry in Madrid, Spain, Rocasolano and the University of Pennsylvania, claims computational models, or “ab initio chemistry”, are used to determine possible reactions. , it could also open the door to using the approach to learn more about the complex chemistry of Venus.