This false color infrared composite of Jupiter's moon Io was produced from images acquired in July and September, 1996, during the first two orbits through the Jovian system by NASA's Galileo spacecraft. The area shown is 11,420 kilometers in width. Grid lines in this cylindrical map projection are superimposed at latitude and longitude intervals of 30 degrees. Deposits of sulfur dioxide frost appear in white and grey hues while yellowish and brownish hues are probably due to other sulfurous materials. Bright red materials (such as the prominent ring surrounding the currently erupting plume Pele) and spots with low brightness or albedo ("black" spots) mark areas of recent volcanic activity and are usually associated with high temperatures and surface changes (Voyager to Galileo or Galileo to Galileo). The color map will be compared to other observations, such as maps of topography and hot spots, to better understand the volcanic and surface processes on this dynamic satellite.
The color in the image is composed of data taken in the near-infrared (756 nanometer), green and violet filters (shown as red, green, and blue respectively) of the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. Images were obtained at resolutions ranging from 10 to 23 kilometers per picture element (pixel) and phase angles (spacecraft-Io-sun angle) from 4 to 55 degrees. The spacecraft range varied from 485,000 to 2,243,000 kilometers. North is to the top of the picture.
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://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo