I o is seen here against the clouds of Jupiter in this spectacular image taken from Galileo spacecraft on September 7, 1996. The color has been enhanced from three separated images taken in the near-infrared, green and violet. Black and red materials correspond to the most recent volcanic deposits. The finest details that can be discerned in these frames are about 4.9km across. Its crater is 300 km across.
North is up.
I n late June 1996, Galileo spacecraft took pictures of Io. These changes were also detected comparing Hubble telescope photos . Io's surface is covered with volcanic deposits that are thought to contain ordinary silicate rock, along with various sulfur-rich compounds that give the satelite its distinctive color. Galileo images have also shown that the Ra Patera plume glows in the dark, perhaps due to the fluorescence of sulfur and oxygen ions created by the breaking apart of sulfur dioxide molecules by energetic particles in the Jovian magnetosphere. The next one shows Euboea Fluctus , an unusual volcanic pyroclastic vent.