Pebbles are seen in lander images, along with cobbles. For example, in this picture, we see the same pebbles that were visible in the Sojourner rover image of the "Cabbage Patch" (path010.htm). In addition, a cobble within the rock "Lamb" (upper left) is apparent. This indicates that Lamb may be a conglomerate (Lamb is 0.32 m x 0.15 m).
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 a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.