title: Sulfuric acid on Europa and the radiolytic sulfur cycle.
abstract: A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, 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-temperature, liquid sulfuric acid may influence geological processes.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. rcarlson@lively.jpl.nasa.gov
authors.forename: R W
authors.initials: RW
authors.lastname: Carlson
authors.forename: R E
authors.initials: RE
authors.lastname: Johnson
authors.forename: M S
authors.initials: MS
authors.lastname: Anderson
mesh_terms: D007053:Ice; D018538:Jupiter; D013455:Sulfur / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000737:chemistry; D013464:Sulfuric Acids / Q000737:chemistry*; D014867:Water
chemical_list: D007053:Ice; D013464:Sulfuric Acids; D014867:Water; D013458:Sulfur Dioxide; D013455:Sulfur; C033158:sulfuric acid