Dust Devil Tracks

When I first saw this image from the HiRise Imager aboard the MRO I focused in on what looks like ripples in the sand and not the dust devil tracks. The blue color usually indicates coarse material), I actually thought the dunes looked like a fingerprint.
I’ve included the press release below (credit: HiRise website and University of Arizona) and you can get many versions including full-sized and wallpapers of the images at the HiRise website; but first: as nice as this image is, the grayscale image is outstanding, I couldn’t help but think of both H.G. Wells and Percival Lowell, see what you think, CLICK HERE.
Here’s the HiRise press release:
This image shows a set of dark sand dunes within the northern part of an unnamed crater in the Terra Cimmeria region.
The dunes have a distinctive shape, with two horns on one end and a rounded edge on the other. The side of the dunes with the horns has a steeper slope and the rounded side a more shallow slope. These types of dunes are called “barchans” and, by analogy with similar dunes on Earth, form in areas with limited sand supply.
The horns of the barchans point in the downwind direction, thereby indicating that the predominant surface winds in this region blew from the east (right side of image). Further evidence of this wind regime is apparent when one zooms into the image. “Wind tails” are visible on the western (left) side of many rocks (many of these rocks may be ejecta from the degraded crater in the northern part of the image). Wind tails are formed by the accumulation of dust and sand in the lee of rocks, which act as wind shadows. Very small light ripples at a scale of a few meters (yards) are also apparent.
The dark, sinuous forms in the image are tracks left by dust devils, which lift bright dust off the surface, revealing the darker surface. Where dust devils cross the dunes, the fine texture on the dunes is undisturbed, indicating that the particles making up the dunes are coarse and fairly immobile.
Images and Source: High Resolution Imaging Science Experiment, Department of Planetary Sciences, Lunar and Planetary Laboratory, The University of Arizona

Comments(1)









Makes me want to meditate. That was just a first impression but it is one of the more interesting, tranquil photos I’ve seen in a while.