“Round” sand dunes on Mars raise questions for scientists

NASA’s Mars Reconnaissance Orbiter (MRO) has captured stunning images of almost perfectly round sand dunes on the surface of the Red Planet.
While dunes of all shapes and sizes are common on Mars, round dunes like this one are a rare sight.
The dunes appear as slightly uneven patches in the image, which was taken on November 22 in the northern hemisphere of Mars by the University of Arizona’s HiRise Imaging Experiment Camera.
“The steep sides of the dunes are slanted south, which could be due to the Martian winds blowing the sand in this direction,” the university’s planetary scientists said in a statement. However, they are not sure why the dunes are almost completely circular.
The image is part of a series taken by HiRise to help monitor how frost on Mars is melting in 60 different locations as the planet’s northern hemisphere reaches the end of winter.
Like Earth, Mars goes through a cycle of the four seasons of summer, spring, autumn and winter.
While the round sand dunes appear devoid of ice in the image, the previous image showed that they were covered in frost.
HiRise, installed on the MRO spacecraft, has been orbiting and surveying sand dunes on Mars since 2006 to help scientists understand how they move and how weather patterns shape these dunes. Data from the high-resolution camera indicates that sand dunes migrate from the equator to the poles at a rate of up to 3.3 feet (1 meter) per Martian year, or 687 Earth days.
It is worth noting that researchers are also using HiRise to study glacier-like formations and deposits at the base of slopes across Mars, which scientists believe may once have been rich in ice, although the source of this ice remains a mystery, according to NASA.
It is important to note that MRO’s primary mission was to search for traces of water on Mars. But while that mission ended 12 years ago on December 21, 2010, the spacecraft still serves as a communications bridge back to Earth for other Mars missions and continues to transmit the amazing images captured by HiRise; The camera finally spotted rocks that looked exactly like a teddy bear.