Mars rover discovers a mystery

WASHINGTON - Agence France-Presse

This image shows spherules on Mars discovered by the rover Opportunity.

NASA’s Opportunity rover, older brother to the Curiosity rover that landed on Mars last month, has made a new discovery that geologists find both puzzling and exciting, the US space agency said on Sept. 14.

Opportunity, which has been on the Red Planet since 2004, has come across an outcrop of tiny spheres, up to around an eighth of three millimeters in diameter, the likes of which scientists have never seen before. “This is one of the most extraordinary pictures from the whole mission,” said Opportunity’s principal investigator, Steve Squyres.

At first glance, the researchers thought the objects resembled iron-rich spheres, nicknamed “blueberries,” discovered near the Opportunity landing site.

The so-called Martian blueberries are formed when minerals separate from water and become hard masses inside sedimentary blocks; they’re part of the evidence Mars used to be wet.

But closer investigation revealed the new discoveries are “different in concentration. They are different in structure. They are different in composition. They are different in distribution,” Squyres said.