The surface of Mars is constantly changing due to the planet's seasonal patterns.
High resolution images captured by NASA's Mars Reconnaissance Orbiter show the effects of the passage of time on the basalt sand dunes located near the red planet's north pole. According to the images, these dunes shift and reform--just like those on Earth.
It was previously though that this dune sea, which covers an area about the size of Texas, was a fairly static region. But new research shows that wind and seasonal erosion can physically transform the area from year to year. According to Discovery News, "The research includes tracking climate and environmental processes active on Mars today, so scientists can figure out what might have been different in the past, when Mars was warmer, wetter and more hospitable for life as we know it."
Take a look through the slideshow (below) to see changes in the dunes near Mars's north pole. Then, check out our slideshow of more extraordinary images of Mars, as well as NASA's most stunning images from 2010.