Abstract
Elemental sulfur aerosols are ubiquitous in the atmospheres of Venus, ancient Earth, and Mars. There is now an evolving body of evidence suggesting that these aerosols have also played a role in the evolution of early life on Earth. However, the exact details of their formation mechanism remain an open question. The present theoretical calculations suggest a chemical mechanism that takes advantage of the interaction between sulfur oxides, SO(n) (n = 1, 2, 3) and hydrogen sulfide (nH(2)S), resulting in the efficient formation of a S(n+1) particle. Interestingly, the SO(n) + nH(2)S → S(n+1) + nH(2)O reactions occur via low-energy pathways under water or sulfuric acid catalysis. Once the S(n+1) particles are formed, they may further nucleate to form larger polysulfur aerosols, thus providing a chemical framework for understanding the formation mechanism of S(0) aerosols in different environments.