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A picture of a variety of geological landforms on Io by NASA's Galileo spacecraft. The smallest features you can see on this picture are 2.6 kilometers across.
The following are visible: mountains several miles high and layered material that forms plateaus.
The many irregularly shaped depressions are called volcanic calderas.
Some lava flows are dark, other lava flows are bright (deposits of sulfur frost). No impact craters are visible - they are quickly filled with lava flows.
A picture by NASA's Galileo spacecraft of mountains and depressions on Io.
The dark, oval shaped depression on the left-hand side of the picture has been filled by lava flows. The large, dark spots at the top right-hand corner are also lava flows filling those depressions.
Shamshu Mons is the mountain in the middle of the picture. It has a 10-kilometer wide canyon running through it. Two other large mountains are also visible.
False color closeup photographs of Jupiter's volcanic moon Io by NASA's Galileo spacecraft during 1999.
These false color closeups make subtle colors more easily visible.
Close-up A: The range of colors indicate that the lava and sulfurous deposits are composed of complex mixtures.
Close-up B: The bright, white deposits seem like a transparent layer of frost.
Close-up C: Detail can now be seen in red areas that were previously seen just as large red areas.
Close-up D: Detail can be seen within the colorful flows of lava.
An enhanced-color picture of the key volcanic areas on Io by NASA's Galileo spacecraft.
These pictures are all scaled to the same proportions. The first picture is 575 kilometers across.
Some of these pictures show new, colorful lava flows.
