Skip to main content
U.S. flag

An official website of the United States government

The distribution of sulfur dioxide and other infrared absorbers on the surface of Io

January 1, 1997

The Galileo Near Infrared Mapping Spectrometer was used to investigate the distribution and properties of sulfur dioxide over the surface of Io, and qualitative results for the anti‐Jove hemisphere are presented here. SO2, existing as a frost, is found almost everywhere, but with spatially variable concentration. The exceptions are volcanic hot spots, where high surface temperatures promote rapid vaporization and can produce SO2‐free areas. The pervasive frost, if fully covering the cold surface, has characteristic grain sizes of 30 to 100 µm, or greater. Regions of greater sulfur dioxide concentrations are found. The equatorial Colchis Regio area exhibits extensive snowfields with large particles (250 to 500 µm diameter, or greater) beneath smaller particles. A weak feature at 3.15 µm is observed and is perhaps due to hydroxides, hydrates, or water. A broad absorption in the 1 µm region, which could be caused by iron‐containing minerals, shows a concentration in Io's southern polar region, with an absence in the Pele plume deposition ring.

Publication Year 1997
Title The distribution of sulfur dioxide and other infrared absorbers on the surface of Io
DOI 10.1029/97GL02609
Authors R. W. Carlson, W. D. Smythe, R. M. C. Lopes-Gautier, A.G. Davies, L.W. Kamp, J. A. Mosher, L. A. Soderblom, F.E. Leader, R. Mehlman, Roger N. Clark, F. P. Fanale
Publication Type Article
Publication Subtype Journal Article
Series Title Geophysical Research Letters
Index ID 70019235
Record Source USGS Publications Warehouse
USGS Organization Crustal Geophysics and Geochemistry Science Center