NASA discovers unusual sand dunes on Mars

If on Earth they might be considered alien traces, but these are signs on Mars .

NASA's Mars Reconnaissance Orbiter (MRO) , a longtime resident of the planet since it launched in 2005, has captured a fascinating image of sand dunes with unusual and remarkable rounded shapes on the surface of the Red Planet.

MRO's High Resolution Imaging Camera (HiRise) has previously captured images of some interesting dunes, including some crescent-shaped dunes. The data also showed that the dunes come in a variety of shapes and sizes. But the latest images show that some of the dunes are almost perfectly circular, which scientists say is "quite unusual."

Beautiful round sand dunes on Mars. (Photo: NASA).

Mars is a dusty, sandy, windy planet. And that makes it the perfect place for sand dunes to form. However, if we look closely, we can see that these dunes are not perfect, precise circles.

'They are still slightly asymmetrical, with steeper slip faces at the southern end. This suggests that the sands generally move south, but the winds can change,' said planetary geologist Alfred McEwen.

MRO's HiRise camera system is currently controlled and operated from Earth by the University of Arizona in the US. MRO took these pictures of the dunes in late November last year. Scientists are focusing on this area to monitor seasonal changes in the dunes. This image shows that the area is free of the frost typical of Martian winter.

Views of Mars like this may seem like another world, but they also show a connection to our own planet. We have beautiful sand dunes on Earth, too, and they tell similar stories about winds and changing seasons.