NASA's Galileo spacecraft captured this dramatic image of mountains on Io in February 2000.
The image was taken when the Sun was low in the sky, illuminating the scene from the left, so it reveals topographic details of Io's surface. A low scarp, roughly 250 meters (820 feet) high, runs from the upper left toward the center of the image. Mongibello Mons, the jagged ridge at the left of the image, rises 7 kilometers (23,000 feet) above the plains of Io, higher than any mountain in North America.
Few of Io's mountains (see also PIA02526) resemble volcanoes. Instead, Galileo scientists believe that the mountains are formed when blocks of Io's crust are uplifted along thrust faults. Angular mountains are thought to be younger, while older mountains have more subdued topography, such as the rise near the top center of this image.
The image has a resolution of 335 meters (1,100 feet) per picture element. North is to the top of the image.
The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://galileo.jpl.nasa.gov . Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm. Image Credit: NASA/JPL/University of Arizona/Arizona State University