Gallery: Images of Mars from the Curiosity rover
After a series of starts and stops, Curiosity is getting back to the science on Mars.
The rover deposited its third scoop of Martian soil into its internal CheMin instrument on Thursday, where it will test the samples' chemical and mineralogical composition.
Much of the sample may have blown away when Curiosity placed the soil in its exterior observation tray, so the fine-grained soil looks lighter than it really is, said project scientist John Grotzinger of Caltech.
Mars Science Laboratory investigators previously ordered the rover to dump its second scoop after noticing "bright material" on the ground.
"In the end, the majority of the science team felt this might be something that's indigenous to Mars," Grotzinger said.
The sieved sample is about the same portion as a baby aspirin, according to JPL, but it represents an important new step in studying the geology of Mars.
CheMin is a powder X-ray diffractor, which analyzes how X-rays are scattered by minerals at an atomic level, identifying them at a greater level than was possible on previous rover missions.
The instrument also uses X-ray fluorescence to determine the ratio of elements in minerals.
The samples, taken from a site called Rocknest, are just the right balance of coarse and fine material for the rover's two sieves.
"We consider ourselves now to be in sort of the promised land," Grotzinger said.
Curiosity's next stop will involve drilling in rocks, which will take about a month, and the rover will spend time driving around Glenelg, a site that intrigues geologists because three different types of terrain converge there.
Glenelg is about 100 yards away from Rocknest.
Curiosity's ultimate destination is Mount Sharp, in the middle of the low-elevation crater where the rover landed on Mars in August.
Layers of rock visible on Mount Sharp provide a chance to discover clues about ancient Mars and the possibility that life could have survived then.
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