Spirit spent most of the last martian winter on standby, conducting science as it waited for winter to pass. This mosaic was made by Spirit's microscopic imager November 27, 2006, and shows "King George Island" after the rock was brushed by the rover's rock abrasion tool. The mosaic covers approximately 6 centimeters (2.4 inches) across and shows the rock's granular nature. The grains are about 1 millimeter (.04 inches) wide. The rover's Mössbauer spectrometer provides evidence the grains have an enhanced amount of the mineral hematite relative to surrounding soils.
NASA / JPL / Cornell University/USGS