By Elizabeth Landau, CNN

As the rover Curiosity tries out more of its tools on Mars, surprises emerge on the Red Planet. After using the rover to scooping dirt, scientists saw something unexpected: small bright objects.

At first, they looked man-made and out of place, said John Grotzinger, Mars Science Laboratory Project scientist and professor at California Institute of Technology, at a news briefing Thursday.

But upon closer examination, these 1-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 probably 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.

Curiosity is currently situated at the "promised land" of Glenelg , a site of particular scientific interest on the Red Planet because three different kinds of terrain exist there.

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.

The rover has been operating on Mars since its spectacular landing on August 6. After Glenelg, it will head to Mount Sharp, a 3-mile-high mountain made of layers of sediment. Curiosity will examine these layers for organic molecules, evidence that life could have once existed there.

What we've done on Mars, and what's next