4 Years on Mars! NASA's Historic Curiosity Rover Marks Anniversary

Four years ago today, NASA's Mars rover Curiosity made one of the most dramatic and harrowing landings in the history of space exploration. On the night of Aug. 5, 2012, a rocket-powered "sky crane" lowered the car-size Curiosity onto Mars' red dirt using cables, then flew off and crash-landed intentionally a safe distance away. Curiosity team members had modeled this novel technique repeatedly using computers, but it had never been tested fully here on Earth, let alone employed on the surf