Sulfuric acid on Europa and the radiolytic sulfur cycle

A comparison of laboratory spectra with Galileo data indicates that hydrate d sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially corr elates with the sulfuric acid concentration, is identified as radiolyticall y altered sulfur polymers. Radiolysis of the surface: by magnetospheric pla sma bombardment continuously cycles sulfur between three forms: sulfuric ac id, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-tem perature, liquid sulfuric acid may influence geological processes.