A big milestone for Nasa's "Curiosity" rover on Tuesday. It has now spent three-thousand days on Mars. Those are Martian days, not earth days, by the way. Martian days, also called "Sols," are more than a half-hour longer than earth days. Nasa says the rover continues to make new discoveries as it gradually climbs up a mountain. It landed on the red planet on august 6th, 20-12 and has been exploring the three-mile tall 'mount sharp' since 20-14.