When NASA makes a new timelapse video, it's not for reminiscence or clout chasing on the Internet. The U.S. space agency recently pulled together images from Curiosity , one of its two robotic rovers on Mars , for a scientific purpose. The two-minute video provides a quick succession of clips spanning six years of exploration at Gale Crater. Each image shows the rover ambling over crumbling lithic landscapes as it slowly climbs Mount Sharp, which rises three miles above the basin floor.  The montage isn't just an intriguing look back on the mission, but a tool for the rover's science team. Using views from Curiosity's right navigation camera, mounted on its head, the researchers analyze the sand grains shifting on the rover's deck.  You can watch the Martian dust churn in the rover's treads in the Instagram post below.…