Mars Rover Opportunity Exploring Matijevic Hill

NASA's Mars rover opportunity had recently produced an image of spherical objects at an outcrop. Researchers checked the spheres' composition by using an instrument called the Alpha Particle X-Ray Spectrometer on Opportunity's arm. Opportunity will continue its work for the next several weeks at the mission's most interesting geological features.

Opportunity kick started its investigation at "Matijevic Hill," that is 22 kilometer wide. It is investigating the site's concentration of small spherical objects reminiscent that differ in several ways from the iron rich spherules termed 'blueberries' discovered in 2004.

The spheres at the Matijevic Hill have a different composition and internal structure.  Opportunity is looking for evidence for the formation of the spheres that are about an eighth of an inch in diameter. 

The only way that nature can produce such small spherical particles is by the action of mineral-laden water inside rocks. One working hypothesis, out of several, is that the new-found spherules are also concretions but with a different composition.

"Right now we have multiple working hypotheses, and each hypothesis makes certain predictions about things like what the spherules are made of and how they are distributed," said Opportunity's principal investigator, Steve Squyres, of Cornell University, Ithaca, N.Y. "Our job as we explore Matijevic Hill in the months ahead will be to make the observations that will let us test all the hypotheses carefully, and find the one that best fits the observations."

The team chose to refer to this important site as Matijevic Hill in honor of Jacob Matijevic (1947-2012), who led the engineering team for the twin Mars Exploration Rovers Spirit and Opportunity for several years before and after their landings.

"We wouldn't have gotten to Matijevic Hill, eight-and-a-half years after Opportunity's landing, without Jake Matijevic," Squyres said.

Opportunity's project manager, John Callas, of JPL, said, "If there is one person who represents the heart and soul of all three generations of Mars rovers -- Sojourner, Spirit and Opportunity, Curiosity -- it was Jake."