NASA scientists won't have to wait until InSight's 2016 drilling mission to see what lies beneath the surface of Mars -- Curiosity is already on the case. After developing a taste for Martian soil late last year, the intrepid rover has started exploring the red planet's bedrock, drilling a 0.63 inch (1.6 cm) wide hole 2.5 inches (6.4 cm) deep into Mars' surface. Curiosity will spend the next several days analyzing the resulting powder in hopes of finding evidence of a once-wet planet. The shallow hole marks the first drilling operation ever carried out on Mars, and getting there wasn't easy. "Building a tool to interact forcefully with unpredictable rocks on Mars required an ambitious development and testing program," explained Louise Jandura, the chief engineer of the rover's sample system. "To get to the point of making this hole in a rock on Mars we made eight drills and bored more than 1,200 holes in 20 types of rock on Earth." The Rover tested its drill by creating a shallower hole earlier this month, though samples will only be used from the second, deeper cavity. Check out the source link for more images of the operation, including an animated GIF of the drill in action.