Scientists need to see results from a chemical analysis of the sample to understand it better, but one theory is that this rock could have once been underwater, Hurowitz said.

The successful usage of the drill marks the final check-out of Curiosity's elaborate suite of instruments.

Back on Earth, however, scientists have encountered a potential problem in one of two terrestrial copies of the CHIMRA instrument, which NASA's Daniel Limonadi describes as a "martini mixer on the spacecraft."

CHIMRA has a sieve that filters out material that is bigger than 150 micrometers, because the CheMin instrument needs tiny particles for its X-ray diffraction work. One of the Earth-based units, the "edge welds are popping and slowly unziping the sieve from the primary structure in CHIMRA over time," Limonadi said.

The same problem has not been observed on its Martian counterpart, or in the second copy of CHIMRA.

Scientists have several theories about why this is happening, but there's no established root cause, Limonadi said. However, it's important to note that this copy of CHIMRA has been used more than Curiosity's CHIMRA unit will be used during its two-year prime mission.

Rover planners are taking precautions just in case the CHIMRA sieve on Mars is vulnerable. For example, they've reduced the sieving time of material in this instrument to expose it to less wear and tear, Limonadi said.

Sieving is the next step for the gray powder recovered from the drill. It will then be fed to the CheMin and SAM instruments to gain more insights about the geological history and potential habitability of Mars, Hurowitz said.

Previous analyses by Curiosity instruments determined that white veins seen in this kind of rock are made of calcium sulfate. The rover will soon use its chemistry experiments to see the full composition of the gray stuff found by the drill.

"Stay tuned, results are coming shortly," Hurowitz said.