A new material for the icy Galilean moons: The structure of sulfuric acid hexahydrate. Issue 9 (20th September 2013)

• Record Type: Journal Article
• Authors: Maynard‐Casely, H. E.; Wallwork, K. S.; Avdeev, M.
• Is Part Of: Journal of geophysical research. Volume 118:Issue 9(2014:Sep.)
• Page Start: 1895
• Page End: 1902
• Publication Date: 2013-09-20
• Subjects: Hydrates -- Icy moons -- Europa -- Ganymede; Planets -- Periodicals; Geophysics -- Periodicals; 559.9
• DOI: 10.1002/jgre.20124
• Languages: English
• ISSNs: 2169-9097

Abstract

Abstract: [1] This study presents a newly identified water‐rich crystalline form of sulfuric acid hydrate, H2 SO4 6H2 O, a hexahydrate. The method of formation of this material suggests that sulfuric acid hexahydrate (SAHx) could be an abundant material on the surface of Jupiter's Galilean ice moons, Europa, Ganymede, and Callisto. The structure of SAHx was determined by the combined use of synchrotron X‐ray and neutron powder diffraction data. The structural arrangement of SAHx exhibits the same water layer topology that has been determined for sulfuric acid octahydrate (SAO), but differs in the stacking of this water layer and the interlayer species. SAHx is observed to form over a large range of solution compositions and displays stability over the temperature range 80 to 190 K. Key Points: Evidence that sulfuric acid hydrates are prevalent on the surface of Europa A new form of sulfuric acid hydrate is described and crystal structure presented The significance of this discovery for the Galilean ice moons is discussed.