English: Original Caption Released with Image:

This color picture of Io, Jupiter's innermost Galilean satellite, was taken by Voyager 1 on the morning of March 5, 1979 at a range of 128,500 kilometers (77,100 miles). It is centered at 8 south latitude and 317 longitude. The width of the picture is about 1000 kilometers (600 miles). The diffuse reddish and orangish colorations are probably surface deposits of sulfur compounds, salts and possibly other volcanic sublimates. The dark spot with the irregular radiating pattern near the bottom of the picture may be a volcanic crater with radiating lava flows.

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Suggested for English Wikipedia:alternative text for images: diffuse reddish and orangish colorations in a field of smooth orange colour are probably surface deposits of sulfur compounds, salts and possibly other volcanic sublimates. The dark spot with the irregular radiating pattern near the bottom of the picture may be a volcanic crater with radiating lava flows.