March 2, 2004 — An extreme close-up of the El Capitan region appears laminated, or composed of layers of firmly united material. At the upper right, in the zone surrounding two larger sphere-shaped particles, this image shows the granularity of the rock the spherules are embedded in. The grains are different near the spherules from with grains farther away. Around the upper spherule, the grain size is increased. This change in grain size might represent a "reaction rim," a feature produced by fluid interacting with the rock around the spherule as the spherule was growing.