NASA's Mars Reconnaissance Orbiter (MRO) has observed a wind-carved rock on the surface of the Red Planet.
MRO's High Resolution Imaging Science Experiment (HiRISE) camera has captured an image of the distinctively fluted surface in the Medusae Fossae region on Mars caused by wind erosion of a soft fine-grained rock.
These features are called yardangs - streamlined hills that are carved by wind erosion from bedrock. According to the HiRISE team, the rock should be "sufficiently erodible for wind to either deflate (pick up) poorly consolidated pieces or scrape the surface by blowing sand."
The word "yardang" is of Turkish origin, which means "steep bank." When viewed from above, yardangs resemble the hull of a boat. HiRISE's resolution allows scientists to view these features and their component layers more closely and provide a better understanding of the material.
According to NASA, the wind direction may have dominated for a very long time to carve the large-scale features into the exposed rock observed in the image from HiRISE.
Scientists said that yardangs reveal the strength and direction of historic winds in the Red Planet, as well as provide insight about the host rock itself. The HiRISE image does not show any presence of boulders or rubble, especially along the steep yardang cliffs and buttresses. According to NASA, the absence of rubble and the scale of the yardangs indicate that the host rock may only be made of weakly cemented fine granules in deposits as thick as about tens of meters or more.
The deposits may have come from the extended settling of volcanic ash, atmospheric dust, or accumulations of wind deposited fine sands. In time, the deposits became cemented and cohesive, as shown by the high standing relief and exposed cliffs.
Yardangs can also be found on Earth as well. According to the Smithsonian Mag, some of the most stunning yardangs could be found in the Gobi desert, where linear yardangs were carved on the landscape by seasonal dust storms.