A cliff slumps outward in these high-resolution views that NASA's Galileo spacecraft captured of the edge of a mountain named Telegonus Mensa on Jupiter's moon Io. Galileo scientists were intrigued by this region after seeing it at much lower resolution in February 2000 So, they targeted high-resolution observations of this cliff when Galileo flew near the south pole of Io in October 2001, in order to study the process of erosion. Water and wind cause most erosion on Earth, but Io has neither surface water nor an atmosphere. The cliff is slumping due to gravity.

The top image sets context with a resolution of 40 meters (131 feet) per picture element and was taken from a distance of about 4,200 kilometers (2,600 miles). The lower picture has a resolution of 10 meters (33 feet) per picture element. Galileo's camera took it from a distance of about 1,000 kilometers (620 miles). North is to the top and the Sun illuminates the surface from the upper right in both pictures.

Images produced by: (top) Dave Williams, Arizona State University
and (bottom) Moses Milazzo, Planetary Image Research Lab. (PIRL), Lunar and Planetary Lab. (LPL), University of Arizona

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/images/io/ioimages.html.

NASA's Planetary Photojournal PIA-02597

November 27, 2001