Sand dunes are not uncommon on the surface of Mars. However, during observations to see how the frost from winter melts on the planet, the Mars Reconnaissance Orbiter captured images of strange Martian dunes that appear almost completely circular. This almost perfectly circular appearance is unusual, which has sparked the interest of NASA and astronomers worldwide.
According to NASA’s page detailing the image, the strange Martian dunes appear to have steeper sides on the south side. NASA says this is because the winds on Mars generally move towards the south. Of course, they can vary, but the effect is clearly seen in these images, where the southern side of the circular dunes is steeper.
The images of these strange Martian dunes were made possible thanks to the High Resolution Imaging Science Experiment (HiRISE), an instrument on the MRO. HiRISE is the largest and the most powerful camera that humanity has ever sent to another planet, and it has delivered exceptional observations about the surface of the Red Planet.
The instrument is operated by the University of Arizona in Tuscon. The image above was taken from a much larger image, showcasing even more strange Martain dunes and the more commonly found dunes. For an idea of just how giant these dunes are, the map is projected at a scale of 25 centimeters per pixel, making these dunes quite massive.
Of course, the meaning of these strange Martian dunes is unclear and might not even mean anything in particular. Still, seeing these sandy hills poking out of the Martian surface in almost perfect circular designs is striking. And, if nothing else, the planet continues to deliver mysteries that astronomers will no doubt pour over as we learn more about the planet.
Data like this will also, no doubt, play a part in how humanity explores Mars, especially once NASA and others start sending manned missions to the Red Planet sometime in the future.