The tablespoon of crushed rock will be sent through the rover’s suite of state-of-the-art instruments, which will provide important information about the ancient landscape at Gale crater and its potential habitability. Curiosity has already uncovered evidence that the spot it is currently placed at, Yellowknife Bay, is an ancient riverbed with a complex history of water. The rover’s science team described the interior sample as time capsule preserving a record of the environment in which the rocks formed.
“We’ve been preparing for this for weeks and months so you can image how happy it makes us to see it successfully completed,” said engineer Avi Okron, a member of the rover drilling team, during a NASA press conference on Feb. 20.
About two weeks ago, Curiosity drilled its first 2-cm-deep test hole on Mars, followed a few days later by a full drill hole 6.4 cm deep. The rover’s rotary percussive drill hammered into the rock as it bored down, collecting a fine powder from at least 5 cm below the surface of the rock. This bit of crushed rock was placed in Curiosity’s scoop, where it was processed further and delivered to the rover’s internal instruments, CheMin and SAM. The former instrument will bombard the sample with X-rays to reveal its composition while the latter will identify the individual elements from inside the rock.
The local geology at Yellowknife Bay suggests that Curiosity will find a rich and complicated history of water. The area around the rover is made of large bedrocks featuring veins containing different minerals and spherical nodules. The rocks are made of fine grains, too small to be resolved by the rover’s hand-held MAHLI camera, indicating that they are likely either siltstone or mudstone, both of which could have been deposited by water. Since the interior sample hasn’t been exposed to surface weathering processes, they will provide a clean example of the early history of Mars and whether or not it was favorable to life.
Because this is the first time the rover’s drill has been used on Mars, the sample may still have some residual contaminants from Earth. The science team actually wants to analyze this impure material because the contaminants will be scrubbed away each time a new sample is taken. Researchers can watch as the contaminants disappear in subsequent samples and figure out exactly what came from our planet and what is native to Mars.