Mars rover Curiosity arrives at 'promised land' of Glenelg, spots shiny objects

The Mars rover Curiosity has arrived at the "promised land" of Glenelg, a site of particular scientific interest on the Red Planet, said John Grotzinger, Mars Science Laboratory Project Scientist and professor at California Institute of Technology, at a news briefing Thursday.

PHOTOS: Curiosity rover lands on Mars

For a little over a week, the rover has been sitting at a place called Rocknest, where it has used its scoop three times to pick up Martian material. The rover threw away the first two samples because they were used for cleaning high-tech instruments. Curiosity inserted material from the third sample into an instrument called Chemistry & Mineralogy (CheMin), which will analyze the minerals of which the material is composed.

"The most important thing about our mobile laboratory is that it eats dirt," Grotzinger said.

Scientists have been seeing something unexpected in the soil where Curiosity is scooping: Small bright objects. At first, they looked man-made and out of place, Grotzinger said. But upon closer examination, these one-millimeter flecks -- about the size of the granules in the soil -- were not uniformly bright, and didn't appear to have come from the rover.

"The majority of the science team felt that this might be something that is actually indigenous to Mars," he said.

There are two prevailing theories about what these flecks might be. One is that certain classes of minerals, when broken along a cleavage plane, would have a flat surface that reflects sunlight. Or, perhaps they're part of a soil-forming process.

This is likely not connected to the object that Curiosity found last week, which NASA scientists believe was "a shred of plastic material, likely benign."

The images that the rover sends from this location will help scientists come up with more hypotheses about how this area was formed. They will eventually pick a rock for the rover to drill into.

"Beginning with some rocks we studied before the scooping began, and going on now for the several weeks in front of us, those images will help guide us and give the team options of what I'm starting to call tours," he said.

The rover has been operating on Mars since its spectacular landing on August 6. After Glenelg, it will head to Mount Sharp, a three-mile-high mountain made of layers of sediment. Curiosity will examine these layers for organic molecules, evidence that life could have once existed there.

Curiosity's mission, which costs $2.6 billion, is slated to last for two years, although other rovers have far outlasted their expected lifetimes. The Opportunity rover is still chugging along, having landed in 2004.