In this VIS image, taken by the NASA - Mars Odyssey Orbiter on October, 13th, 2013, and during its 52.488th orbit around the Red Planet, we can see a portion (approx. one half) of an ancient Unnamed Impact Crater (probably endowed with a dusty and rocky "Pedestal"), that is completely surrounded by the "Erg" (---> a Sea of Sand Dunes which, as you know, is located near and all around the North Polar Cap).
It is now Springtime over the Northern Hemisphere of Mars, and all these Dunes (or, if you prefer, this whole gigantic Dunefield - such as the aforementioned "Erg" - which once, perhaps - and according to the "vision" of a few Planetary Scientists -, was the bottom of an Ocean - that is commonly known as "Oceanus Borealis"), in a relatively short time (such as in a few months) will darken, as the Winter Frost that covers them sublimates into the Atmosphere, as a consequence of a rise - which is going to be quite remarkable, for this Region of Mars - in the average daytime temperature of the Surface.
Latitude (centered): 81,012° North
Longitude (centered): 190,215° East
This image (which is a crop taken from an Original Mars Odyssey Orbiter b/w and NON Map-Projected frame published on the NASA - Planetary Photojournal with the ID n. PIA 17716) has been additionally processed, reduced in size, contrast enhanced, Gamma corrected and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Mars Odyssey Orbiter and then looked down, towards the Surface of Mars), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.