The rover snapped an image of a thin, light-colored item laying on top of the reddish ground. It stands out from the surrounding surface.
Curiosity's Earth handlers labeled the enigmatic piece as "Pettegrove Point Foreign Object Debris." Pettegrove Point is the area the rover is currently exploring inside the Gale Crater on Mars.
There was some concern the rover might have dropped a piece of itself. "In fact, it was found to be a very thin flake of rock, so we can all rest easy tonight -- Curiosity has not begun to shed its skin," Curiosity team member Brittney Cooper declared, after a closer look.
Curiosity got a better view of the rock by using its ChemCam to zoom in and identify it as a natural piece of the Mars landscape.
The Curiosity team had a legitimate concern when it came to identifying the object. In 2012, the rover spotted an equally mysterious bright object on the surface that turned out to be a tiny piece of plastic material shed from the rover.
At least this time, Curiosity seems to be holding itself together just fine.