NASA's Mars Exploration Rover Opportunity used its microscopic
imager to get this view of the surface of a rock called "Block
Island" during the 1,963rd Martian day, or sol, of the rover's
mission on Mars (Aug. 1, 2009). The triangular pattern of small
ridges seen at the upper right in this image and elsewhere on
the rock is characteristic of iron-nickel meteorites found on
Earth, especially after they have been cut, polished and etched.
Block Island has been identified as an iron-nickel meteorite
based on this surface texture and analysis of its composition by
Opportunity's alpha particle X-ray spectrometer. At about 60
centimeters (2 feet) across, it is the largest meteorite yet
found on Mars. This image shows a patch 32 millimeters by 32
millimeters (1.3 inches by 1.3 inches) on the surface of Block
Island while the target was fully illuminated by the sun. This
target on the rock is informally named "New Shoreham." The
vertical white streaks, especially near the top and bottom of
the image, are artifacts c