As NASA's Mars Exploration Rover Spirit began collecting images for a
360-degree panorama of new terrain, the rover captured this view of a
dark boulder with an interesting surface texture. The boulder sits about
40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet)
away from Spirit. It is one of many dark, volcanic rock fragments -- many
pocked with rounded holes called vesicles -- littering the slope of "Low
Ridge." The rock surface facing the rover is similar in appearance to the
surface texture on the outside of lava flows on Earth.
Spirit took this approximately true-color image with the panoramic camera
on the rover's 810th sol, or Martian day, of exploring Mars (April 13,
2006), using the camera's 753-nanometer, 535-nanometer, and 432-nanometer
filters.