From http://www.jpl.nasa.gov/galileo/

   
                           Pele Plume Deposit on Io
                                       
   
   
   NOTE: This JPEG image is made available in order to share with the
   public the excitement of new discoveries being made via the NASA/JPL
   Galileo spacecraft. Galileo scientists are in the process of
   calibrating and validating this data. The full digital image necessary
   for scientific analysis will be released within one year of receipt of
   this orbit's last data.
   
   This image is available only on the WWW; it is not available in
   hardcopy or other forms.
   
   
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Pele Plume Deposit on Io

   
   
   The varied effects of Ionian volcanism can be seen in this false color
   infrared composite image of Io's trailing hemisphere. Low resolution
   color data from Galileo's first orbit (June, 1996) have been combined
   with a higher resolution clear filter picture taken on the third orbit
   (November, 1996) of the spacecraft around Jupiter.
   
   A diffuse ring of bright red material encircles Pele, the site of an
   ongoing, high velocity volcanic eruption. Pele's plume is nearly
   invisible, except in back-lit photographs, but its deposits indicate
   energetic ejection of sulfurous materials out to distances more than
   600 kilometers from the central vent. Another bright red deposit lies
   adjacent to Marduk, also a currently active ediface. High temperature
   hot spots have been detected at both these locations, due to the
   eruption of molten material in lava flows or lava lakes. Bright red
   deposits on Io darken and disappear within years or decades of
   deposition, so the presence of bright red materials marks the sites of
   recent volcanism.
   
   This composite was created from data obtained by the Solid State
   Imaging (CCD) system aboard NASA's Galileo spacecraft. The region
   imaged is centered on 15 degrees South, 224 degrees West, and is
   almost 2400 kilometers across. The finest details that can discerned
   in this picture are about 3 kilometers across. North is towards the
   top of the picture and the sun illuminates the surface from the west.
   
   Launched in October 1989, Galileo entered orbit around Jupiter on
   December 7, 1995. The spacecraft's mission is to conduct detailed
   studies of the giant planet, its largest moons and the Jovian magnetic
   environment. The Jet Propulsion Laboratory, Pasadena, CA manages the
   mission for NASA's Office of Space Science, Washington, DC.
   
   This image and other images and data received from Galileo are posted
   on the World Wide Web, on the Galileo mission home page at URL
   http://www.jpl.nasa.gov/galileo.