[NormsRevenge]

Soft Rock Yields Clues to Mars' Past

This image taken by the Mars Exploration Rover Spirit shows the rock outcrop dubbed "Clovis." The rock was discovered to be softer than other rocks studied so far at Gusev Crater after the rover easily ground a hole into it with its rock abrasion tool. An analysis of the interior of the hole with the rover's scientific instruments found higher concentrations of sulfur, bromine and chlorine compared to basaltic, or volcanic, rocks at Gusev. This might indicate that Clovis was chemically altered, and that fluids once flowed through the rock depositing these elements. Spirit's solar panels can be seen in the foreground. This image was taken by the rover's navigation camera on sol 205 (July 31, 2004).

[NormsRevenge]

The Call of the Dark Rocks

This false-color image taken by the Mars Exploration Rover Spirit shows a group of darker rocks dubbed "Toltecs," lying to the southeast of the rover's current position. The rocks are believed to be basaltic, or volcanic, in composition because their color and spectral properties resemble those of basaltic rocks studied so far at Gusev Crater. Scientists hope to use these presumably unaltered rocks as a geologic standard for comparison to altered rocks in the area, such as "Clovis." This image was taken by the 750-, 530- and 430-nanometer filters of rover's panoramic camera on sol 220 (Aug. 15, 2004).