Sojourner's left rear wheel is perched on the rock "Wedge" in this image, taken on Sol 47 by the Imager for Mars Pathfinder (IMP). The rover's Alpha Proton X-ray Spectrometer (APXS) is the cylindrical object extending from the back of the rover.
This image and PIA01557 (right eye) make up a stereo pair.
Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech).
Photojournal note: Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998.