 Drilling into the ground on Earth is quite easy, but on Mars there will be much less gravity and so it is hard to generate the down-force needed to force a drill into the rock. Similarly, rotating a powerful drill while a rover is positioned on soft sand could be dangerous. An ultrasonic drill tool can pulverise rock through high-frequency vibrations without needing excessive force, so it has the potential to allow exploration deep below the surface where evidence of the past climate, and perhaps life, could lie. |