Sand dunes are not uncommon on the Martian surface. However, during observations to observe how the planet’s winter frost is melting, the Mars Reconnaissance Orbiter captured images of bizarre Martian dunes that appear almost perfectly round. This nearly perfectly round appearance is unusual and has attracted the attention of NASA and astronomers around the world.

The strange Martian sand dunes appear to have steeper sides on the south side, according to NASA’s page detailing the image. NASA says this is because windows on Mars often move south. Of course they can vary, but the effect is clear in these images, where the south side of the round dunes is steeper.

Images of these strange Martian dunes were made possible by the High Resolution Imaging Spectroradiometry Science Experiment (HiRISE), an MRO instrument. HiRISE is the largest and most powerful camera humanity has ever sent to another planet, providing outstanding observations of the Red Planet’s surface.

The facility is operated by the University of Arizona in Tuscona. The above image is from a much larger view showing the more common sand dunes as well as the even weirder Martain Dunes. To understand how big these dunes are, the map is projected at 25 centimeters per pixel.

Of course, the meaning of these strange Martian sand dunes is ambiguous or may not even make any particular sense. All that being said, it’s awe-inspiring to watch these dunes protruding from the Martian surface in near-perfect circular formations. And if nothing else, the planet continues to unravel mysteries that astronomers will no doubt uncover as we learn more about the planet. Data like this will undoubtedly play a role in how humanity explores Mars, especially when NASA and others begin sending manned missions to the Red Planet in the future. Source