Scientists have found that summer on Mars is a little different from our planet's hot season -- especially at the north poles.
NASA released images of a dune field that formed near the base of the North Polar cap on Mars. Scientists believe the dune fields formed from layers of dusty ice that were eroded by strong polar winds.
However, the images taken during the Martian northern summer showed clearly visible patterns within the dunes, completely frost-free.
See images of the surface of then planet during the martian summer:
In the mosaic, the NASA's HiRISE satellite shows off the Red Planet's polar ice cap in conjunction with its distinct dark spiraling troughs.
Dunes that are closer to the base of the polar cap are long and parallel, which scientists believe is a response from strong winds blowing from the direction of the cap.
The dunes begin to take on a more crescent shape the further they are from the polar cap. These dunes are called "barchan dunes" -- a term that was introduced by Russian naturalist Alexander von Middendorf in 1881 and really just means "crescent-shaped dunes."
This observation is just one of a series conducted by HiRISE of dunes, each showing measurable changes across Mars. This discovery adds to the accumulating evidence that such active processes are happening all over the planet.
The HiRISE satellite, operated by the University of Arizona, was built by Ball Aerospace & Technologies Corp. in Boulder, Colorado at NASA's Jet Propulsion Laboratory.