While its twin Spirit is currently struggling to get out of Troy, the sandy trap that has been keeping it hostage since late April, Opportunity is having a field day studying a rock known as Marquette Island. On Sol 2070 (Nov. 19), the explorations robot used its rock abrasion tool's wire brush to investigate the peculiar formation, in an attempt to get more insight into its composition. The announcement was made by scientists at the NASA Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology (Caltech), in Pasadena, California.

Using the rover’s front hazard-avoidance camera, scientists collected this image of the rock, shortly after the abrasion tool completed its task, The targeted area, which is known as Peck Bay, is revealed in the small, circular and dark shape just below the end of Opportunity's robotic arm. The “Bay” only has a diameter of about 5 centimeters (2 inches), but experts hope that this will be enough to allow them a sneak peak into the rock internal composition. Finding it out is very important, because it may provide them with clues as to past climate changes on Mars, as well as details of the planet's wet past.

Astronomers jokingly say that Endeavor has to be driving down Meteorite Alley. Since 2005, it discovered five such structures, of which one in 2005, just one year into its mission and all the other four in 2009. The first was Block Island, which the rover spent the most time studying, in July. Then, at the end of September, it came across Shelter Island, when the robot completed its 2,020th Sol on the Red Planet. On October 13, it found Mackinac Island, which was named in what is now shaping to be the tradition of adding “Island” at the end of every meteorite's name. All of the meteorites that were found until Marquette Island were determined to be made out mostly of iron and nickel.

Opportunity used its navigation camera to record the new image during its 2,056th Martian day (November 5). “The dark-toned rock stood out so prominently in more distant views on earlier sols that the rover team referred to it as 'Sore Thumb' before assigning the Marquette name in accord with an informal naming convention of choosing island names for the isolated rocks that the rover is finding as it crosses a relatively barren plain on its long trek from Victoria Crater toward Endeavor Crater,” the press release accompanying the image says.