When NASA's Curiosity Rover first dug into the Martian desert, it found clays that could only have been formed by fresh water. This meant that, around three billion years ago, Mars was a watery planet. But did it support life? On the first anniversary of its landing, halfway through its primary mission, Curiosity is headed to the foothills of Mount Sharp, an 18,000-foot mountain whose rocks could provide clues to a time on Mars when life could have thrived. But because Curiosity is driving at a careful pace--about a hundred yards a day--the journey will take eight or nine months to complete.
The rover, roughly the size of a car, landed on Mars exactly where t had been aimed, within Gale Crater, a 96-mile-wide scar from an asteroid impact that took place at least 3.5 billion years ago. In that time layers of sediment filled much of the crater, which were then somehow carved away, leaving Mount Sharp at the center.
Mount Sharp, in the middle of Gale Crater, exposes many layers where scientists anticipate finding evidence about how the ancient Martian environment changed and evolved. In the Glenelg area, where Curiosity worked for the first half of 2013, the rover found evidence for an ancient wet environment that had conditions favorable for microbial life. This means the mission already accomplished its main science objective
The image of Mt. Sharp shown above is color balanced, which is why the Martian sky appears to be blue.