With drives on July 4 and July 7, the nuclear-powered, six-wheel Curiosity rover has departed its last science target in the "Glenelg" area and commenced a many-month overland journey to the base of the mission's main destination, Mount Sharp, NASA officials said.
The one-tonne rover finished close-up investigation of a target sedimentary outcrop called "Shaler" last week. On July 4, it drove 18 meters away from Shaler.
On July 7, a second drive added another 40 meters on the trip toward a destination about 8 kilometres away, the entry to the lower layers of Mount Sharp.
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 favourable for microbial life.
This means the mission already accomplished its main science objective, the US space agency said.