Mars Exposes "Morse Code" in Dunes, NASA Finds

NASA released an image of "Martian Morse Code" as its Picture of the Day, explaining that the photo depicts dark dunes upon the surface of the red planet. The unusual dune patterns that resemble the dots and dashes of Morse code evoke the idea of a Martian civilization leaving a message for the human race to find.

The patterns are simply the result of the natural topography on Mars. The dot and dash formations of the dunes are generally indicative of the direction of winds sweeping the planetary surface. However, the complexity of these particular dunes makes it difficult to tell what that direction might be.

NASA scientists think that a rounded depression, most likely an ancient impact crater that has long since filled up, is keeping much of the Martian sand out of the reach of the winds, preventing regular dune patterning. The depression in the Hagal Dune field has "focused the wind, and also limited the amount of sand available for formation of the dunes," NASA analyst Veronica Bray informed Gizmodo.

The linear "dash" patterns are formed due to the force of bi-directional winds coming from directions at right angles to the dune, combining to funnel sand into the elongated shape. The "dots" are what are called "barchanoid dunes" and they build up in cases where something comes to interrupt the process that foms the lengthier dunes.

Barchanoid dune formation is still something of a mystery to NASA scientists, which is why the image is of great interest to the agency. The photo was captured using the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

HiRISE is collecting images of the Martian surface to help scientists better understand the forces shaping its planetary landscape. The message of the Martian Morse code may contain secrets, but rather than words, they are hints about the workings of Martian natural processes.