The brown, orange areas are probably covered by sulphur or a mixture containing sulphur. This is the highest resolution color global mosaic of Io. It was then projected to an ortographic projection centered at 0 degrees latitude and 315 degrees longitude. Almost all the features visible here have volcanic origins, including several calderas and eruption plumes that were active at the time of the Voyager 1 encounter. Global Mercator Mosaic Io's volcanic plains are shown in this Voyager 1 image mosaic which covers the area roughly from latitude 60 degrees N. to latitude 60 degrees S. and longitude 100-345.
North is up.
Numerous volcanic calderas, lava flows, and volcanic eruption plumes are visible here. The bright whitish patches probably consist of freshly deposited sulfur dioxide frost. This image is a mosaic of Io based of Galileo C3 Io images. The USGS controlled global mosaic was used for reference. This image of Jupiter and its satellite Io were taken on March 5, 1994.