Why Don't We See the Curiosity Rover's Arm When it Takes a Selfie?

Every time the Curiosity rover takes a 'selfie' on Mars, we get the same questions: "How was this picture taken?" "Why isn't the rover's arm or the camera visible in this picture?" "In all of Curiosity's selfies, the camera mast is never visible... why?" And (sigh) "What is NASA hiding???" The answer is simple and […]