When NASA's Curiosity Rover quietly rolls across the Marseilles, it leaves a very subtle business card this points to his birthplace, which is several tens of millions of kilometers away. Over the 1
2.5-mile terrain, it has slowly rolled over and taken samples and photos along the way, leaving tracks in the ground that trace its way back to the starting point of the journey at the Bradbury Landing site in Gale Crater.  Most of the tread on the Rover wheels consists of a simple yet effective zig-zag pattern that provides a long-lasting profile with good purchasing power on dry and loose Martian soil. The entire wheel does not have the same tread, but a small segment of each tread is dedicated to a series of cutouts. The pattern of the cutouts ".- / .-. / .- .. "describes the initials of NASA's Jet Propulsion Laboratory on the Morse code (JPL). As the rover explores Mars, he prints the letters and makes a slight bow to his birthplace wherever he goes.
Although the markings are part of a vanity project, they have a useful function. When the cameras on board examine the tread left by the wheels, the different patterns introduced by the Morse Code provide some degree of scaling that researchers can use as a reference to indicate the distance, even if the terrain in the photograph has no features is.