Story highlights A NASA camera's captured sand dunes of dots and dashes on Mars

Scientists don't know how the Morse code-like dunes formed

(CNN) Yes, astronomers have discovered dark sand dunes on Mars that resemble Morse code. But no, they don't think little green men are trying to tell us something.

The images of the dark dunes were snapped in February by a high-resolution camera on NASA's Mars Reconnaissance Orbiter.

So just what are they? A report from the red planet, or just a weird little topographical anomaly? Definitely the latter, NASA explains.

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The dunes have formed in a depressed area that's probably an old asteroid impact crater. The circular depression has had a weird effect on both the amount of sand available to form dunes and the way the winds carve up the dunes, NASA said. So instead of the long, flowing lines of dunes we're used to seeing on our planet, the winds on this part of Mars swirled in such a way to create distinct dots and dashes of dunes.

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