Curiosity is continuing its mission on Mars and, while it looks for a suitable location to test its rock drill for the first time, it managed to use a less impressive but equally important piece of equipment for the first time, its brush.
The brush is designed to help clear away the Martian dust to reveal the rocks underneath. This was just a test of the equipment; NASA wasn't looking to discover anything. But the tool has an important purpose.
For one, it enables Curiosity's imaging equipment to get a better look at what's beneath the dust, particularly the Alpha Particle X-ray Spectrometer and the Mars Hand Lens Imager, found at the end of Curiosity's arm, along with the brush.
Second, it makes it possible to get a sample from inside the rock without contaminating it with the dust on the surface.