The calibration target for the Mars Hand Lens Imager (MAHLI) instrument also includes a “Joe the Martian” character, color references, a metric bar graphic, and a stair-step pattern for depth calibration. […]
The Joe the Martian character appeared regularly in a children’s science periodical, “Red Planet Connection,” when Edgett directed the Mars outreach program at Arizona State University, Tempe, in the 1990s. Joe was created earlier, as part of Edgett’s schoolwork when he was 9 years old and NASA’s Mars Viking missions, launched in 1975, were inspiring him to dream of becoming a Mars researcher.