Like a circular ripple intersecting a flowing stream, the tracks created by NASA's Spirit rover are reminiscent of a Zen rock garden. Highly prized in Japan, such gardens use rocks and raked gravel to suggest entire landscapes of islands, seas, and streams. A centuries-old Buddhist and Taoist tradition, the creation and contemplation of rock gardens serves to reduce the complexity of life and allow the individual to develop inner calm, though whether or not Spirit is developing robotic inner calm may be open to speculation.

Spirit took this mosaic of images with the navigation camera on martian day, or sol, 476 (May 5, 2005), at the end of a drive. Spirit previously had to abandon climbing hills on Sol 455 (April 14, 2005) because of steep slopes. The backtracking was fortuitous, allowing the science team to discover layered outcrops of rock that had been overlooked on the first drive past this area. Since then, Spirit has been examining those "Methuselah" outcrops in the "Columbia Hills" for several weeks. This mosaic looks back at the tracks Spirit left while backtracking and heading to "Methuselah."