Strange Circular Sand Dunes Discovered on Mars by NASA Spacecraft

Sand dunes of many shapes and sizes are common on Mars. In this example, the dunes are almost perfectly circular, which is unusual. Credit: NASA/JPL-Caltech/University of Arizona Sand dunes of many shapes and sizes are common on <span class= »glossaryLink » aria-describedby= »tt » data-cmtooltip= » Mars Mars is the second smallest planet in our solar system and the fourth […]