NASA's Curiosity rover has reached its ultimate destination, Mount Sharp, after more than two years of exploring the Martian surface, NBC News reported. "We have finally arrived at the far frontier that we have sought so long," said John Grotzinger, the principal investigator for the $2.5 billion Curiosity mission. Curiosity will build a time line of Mars' climatic and geological shifts using the info it gleans from the 3-mile-high mountain's rock layers.
