This false-color image taken by the panoramic camera on the Mars Exploration Rover Spirit shows the rock dubbed "Pot of Gold" (upper left), located near the base of the "Columbia Hills" in Gusev Crater. Scientists are intrigued by this unusual-looking, nodule-covered rock and plan to investigate its detailed chemistry in coming sols. This picture was taken on sol 159 (June 14, 2004).

To the right is a set of rocks referred to as "Rotten Rocks" for their resemblance to rotting loaves of bread. The insides of these rocks appear to have been eroded, while their outer rinds remain more intact. These outer rinds are reminiscent of those found on rocks at Meridiani Planum's "Eagle Crater." This image was captured on sol 158 (June 13, 2004).