The track pattern — dot-dash-dash-dash, dot-dash-dash-dot, dot-
dash-dot-dot (".--- .--. .-..") — spells out "JPL" in Morse
code, which translates letters and numbers into a series of
short ("dot") and long ("dash") signals. Curiosity's signature
wheel-print was a nod to NASA's lead center for unmanned
planetary exploration, which built the rover and now commands it
as Curiosity prepares to explore Mars in search of conditions
habitable to past or present life. The dashes and dots are more
than just an autograph on the ground. They serve as "visual
odometry" marks, which allow Curiosity's engineers to determine
the position and orientation of the rover, as well as how far it
traveled, by analyzing images of its tracks. "We have
intentionally put holes in the wheels to leave a unique track on
Mars," Heverly said. "So if we are in sand dunes where we don't
have lots of rock features around us, we can use those patterns
to do our visual odometry." In addition to the Morse code JPL,
Curiosity's wheels also feature