A selfie taken by NASA's Curiosity Mars rover on Sol 2291 (Jan. 15) at the "Rock Hall" drill site, located on Vera Rubin Ridge. (Credit:NASA/JPL-Caltech/MSSS)

LOS ANGELES, Jan. 29 (Xinhua) -- NASA's Curiosity rover has taken its last selfie on Vera Rubin Ridge and descended toward a clay region of Mount Sharp, according to a release of NASA's Jet Propulsion Laboratory (JPL) on Tuesday.

The twisting ridge on Mars has been the car-size rover's home for more than a year, providing scientists with new samples to puzzle over.

Curiosity drilled its 19th sample at a location on the ridge called Rock Hall on Dec. 15 last year. The spacecraft used its Mars Hand Lens Imager camera on the end of its robotic arm to take a series of 57 pictures on Jan. 15, which were stitched together into this selfie.

The "Rock Hall" drill hole is visible to the lower left of the rover, according to the mission team. The scene is dustier than usual at this time of year due to a regional dust storm.

Curiosity has been exploring the ridge since September 2017. It is now headed into the "clay-bearing unit," which sits in a trough just south of the ridge.

Clay minerals in this unit may hold more clues about the ancient lakes that helped form the lower levels on Mount Sharp, according to the team.

Curiosity landed near Mount Sharp in the Gale Crater on Mars in August 2012 and reached the base of the mountain in 2014. It has since traversed through a diversity of environments where both water and wind have left their imprint.