A yardang sounds like a nautical term: “Swab down the yardang, matey, or you’ll walk the plank!” And, from certain angles, yardangs do look like boats. But they have nothing to do with the sea—they are massive geologic formations, on Earth and on Mars, that are formed by the steady erosion of rock by the wind.
From the HiRISE science team, which took the picture above:
Yardangs are streamlined hills that are carved by wind erosion from bedrock. The rock must be sufficiently erodible for wind to either deflate (pick up) poorly-consolidated pieces or scrape the surface by blowing sand. HiRISE resolution allows us to view yardangs and the component layers more closely, and to get a better understanding of the material.
“Yardang” is a word of Turkish origin, meaning “steep bank.“ When viewed from above, yardangs can look like the hull of a boat.
Resembling a boat? Yarrr…
Other experiments, including the Mars Express spacecraft, have documented the appearance of yardangs on the martian surface. The picture below shows yardangs near the base of the Martian volcano, Olympus Mons.
Yardangs can also show up much closer to home. Here on Earth, some of the most spectacular yardangs are in the Gobi desert, where seasonal dust storms have carved beautiful linear yardangs into the landscape.
H/T to Corey Powell who tweeted about Yardangs earlier this week.