NASA Mars Rover Opportunity Reveals Geological Mystery Small
spherical objects fill the field in this mosaic combining four
images from the Microscopic Imager on NASA's Mars Exploration
Rover Opportunity. Image credit: NASA/JPL-Caltech/Cornell Univ./
USGS/Modesto Junior College› Full image and caption › See image
gallery PASADENA, Calif. -- NASA's long-lived rover Opportunity
has returned an image of the Martian surface that is puzzling
researchers. Spherical objects concentrated at an outcrop
Opportunity reached last week differ in several ways from iron-
rich spherules nicknamed "blueberries" the rover found at its
landing site in early 2004 and at many other locations to date.
Opportunity is investigating an outcrop called Kirkwood in the
Cape York segment of the western rim of Endeavour Crater. The
spheres measure as much as one-eighth of an inch (3 millimeters)
in diameter. The analysis is still preliminary, but it indicates
that these spheres do not have the high iron content of Martian
blueberries. "Thi