Almost after two years of its arrival on the Martian surface, NASA's rover Curiosity has finally done its drilling in its most ultimate target Mt. Sharp, which is a 3-mile-high mountain in the middle of Gale Crater.

Ashwin Vasavada, deputy project scientist for the Mars Science Laboratory said, "It feels great. It's been a long time coming, but I think we're going to find that it was worth the drive. There was a reason we came here. I think we just all feel that it's nice to have all the pressure of driving behind us".

He added that the plan for Curiosity is to stick around the spot for a week or two, while the samples collected run through parts of the rover's internal chemical lab.

Before this, a drilling was done last week in which 2.6 inches were drilled into an outcrop on the base of Mt. Sharp. Samples were then pulled out of this powdered rock that is the softest yet that has been drilled. Fromall the samples generated, scientists will be looking for clay-rich material that could hold signs of past water on the Red Planet.

The drilling phase marks the start of a new period in Curiosity's career on Mars. After its landing in August 2012, rover took an alternate path to study the spot called Yellowknife Bay. The robotic explorer dug up evidence of the past wet environment with the right chemical ingredients for microbial life.

All this time, the scientists have been pushing rover to get to its original target, Mt. Sharp, as they believed that the clay-rich layers present in that place could hold the story of the Red Planet's past habitable environments.

In this span of two years, Curiosity's drivers have been picking their way carefully across the rocky surface as the team noticed an alarming amount of damage on the rover's thin wheels.