The hole, 2.65 millimetres (0.1 inch) deep and 45.5 millimetres (1.8 inches) in diameter, was hailed as a significant achievement by scientists working on the Mars exploration mission.

"I didn't think that it would cut this deep. In fact, when we saw virtually a complete circle, I was thrilled beyond anything I could have ever dreamed," said Steve Gorevan, lead scientist for the rock abrasion tools on the twin US Mars rovers.

Spirit, which was paralysed for several days due to a computer glitch, is now working normally, NASA said.

After probing the rock, Spirit will move 250 metres towards a crater to the northeast, the National Aeronautics and Space Administration said. 

Meanwhile, Spirit's twin, Opportunity, inched towards a rocky outcrop which scientists want to study.

The two rovers are on a three-month mission to examine Martian soil and rocks to determine whether the planet once had the ability to host life.