Spirit hunkers down for winter; Opportunity sampling 'Chocolate Hills'

On Sol 2174 (Feb. 13, 2010), the robotic arm (IDD) was positioned to the most favorable orientation for winter. Documentary imaging is being collected of the terrain and rover. On board flash memory is being emptied, getting down all essential data products. A special table of long-range UHF communication passes is being developed to cover the entire winter period and beyond. As energy levels decrease rover wake times are shortened and many communication passes are being deleted.

As of Sol 2176 (Feb. 15, 2010), the rover solar array energy production was to 173 watt-hours with an atmospheric opacity (tau) of 0.361 and a dust factor of 0.526. Total odometry is 7,730.50 meters (4.80 miles).

This false-color image shows the rock "Chocolate Hills," perched on the rim of the 10-meter (33-foot) wide "Concepcion" crater. Patches of unusual dark material can be seen on top of this rock and on several others in the scene. The image was acquired by the Opportunity rover's panoramic camera (Pancam) on its 2144th Martian day, or sol, on Mars (Feb. 3, 2010), using several of the panoramic camera's filters (at wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers). The false-color enhancement increases the contrast between different rock and soil types on the Martian surface. Credit: Image Credit: NASA/JPL-Caltech/Cornell

Opportunity is positioned near the rim of the very young crater "Concepcion."

The instruments on the rover's robotic arm (IDD) have been investigating targets on the rock called "Chocolate Hills." This rock is of interest because it exhibits a dark rind or crust that may be impact melt. On Sol 2152 (Feb. 11, 2010), the rover made a small turn to reposition the robotic arm for targets on the surface of the Chocolate Hills. On Sol 2154 (Feb. 14, 2010), the IDD collected a Microscopic Imager (MI) mosaic, then placed the Alpha Particle X-ray Spectrometer (APXS) on a light-colored rind called "Arogo." On Sol 2157 (Feb. 17, 2010), the rover repeated these two sets of measurements on a target called "Tears."

Further investigation of this rock is expected before the rover drives away. As of Sol 2157 (Feb. 17, 2010), the solar array energy production was 305 watt-hours with an atmospheric opacity (tau) of 0.432 and a dust factor of 0.496. Total odometry is 19,335.35 meters (12 miles).

Source: Jet Propulsion Laboratory
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