Curiosity's Secret Message...

If you look carefully at Curiosity’s wheels, you might notice that along with treads, there are square and rectangular holes. According to JPL Rover Mechanical Engineering Team Manager Richard Rainen, these holes are actually odometer markers. Rainen said,“There are asymmetric patterns, actually holes, inside the wheels of the rover that will leave an imprint on the surface of Mars. We’re going to be looking at these imprints and verifying that it has traversed the distance it expects to traverse. If it looks like it’s not traversing, even though the wheels are going, that is an indication that the vehicle is getting stuck and it will stop and call back home.”

But back in 2007, when the Curiosity team at JPL was putting together the rover, its wheel cleats had a raised pattern with the letters “JPL,” leaving a little stamp of the rover’s birthplace everywhere it rolled. But the finished Curiosity rover wound up with a different pattern with holes and  the engineers got to make the markers in any shape they wanted. So what pattern did JPL choose to put on Curiosity’s wheels? The holes are in a pattern of short squares and longer rectangles - almost like dots and dashes. Morse code… And what does it spell out in Morse code? JPL!

J . - - - 
P . - - . 
L . - . .

The wheels of Curiosity will soon begin to leave there secret message on the surface of Mars. Software is being uploaded now that will allow the rover to begin moving about Gale Crater.

Source - http://www.arrl.org/news