Zooming on the yardangs of Mount Sharp with Remote Micro Imager - sol 1994

Yardangs are common in some regions on Mars, especially in the

Medusae Fossae Formation The Medusae Fossae Formation is a large geological formation of probable volcanic origin on the planet Mars. It is named for the Medusa of Greek mythology. "Fossae" is Latin for "trenches". The formation is a collection of soft, easily eroded de ...

. This formation is found in the Amazonis quadrangle and near the equator. They are formed by the action of wind on sand sized particles; hence they often point in the prevailing direction that the winds were blowing when they were formed. Because they exhibit very few impact craters they are believed to be relatively young. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer ...

. Yardangs are parts of rock that have been sand blasted into long, skinny ridges by bouncing sand particles blowing in the wind.Yardangs in Arsinoes Chaos
University of Arizona HiRISE Operations, 04 January 2015 Layers are seen in parts of the formation. A resistant caprock on the top of yardangs has been observed in Viking,

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American robotic space probe developed by NASA's Jet Propulsion Laboratory and launched November 1996. MGS was a global mapping mission that examined the entire planet, from the ionosphere down through t ...

, and

HiRISE High Resolution Imaging Science Experiment is a camera on board the '' Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction ...

photos. Images from spacecraft show that they have different degrees of hardness probably because of significant variations in the physical properties, composition, particle size, and/or cementation. File:Medusae Fossae Formation.jpg, Medusae Fossae Formation as seen with Mars Odyssey's

THEMIS In Greek mythology and religion, Themis (; grc, Θέμις, Themis, justice, law, custom) is one of the twelve Titan children of Gaia and Uranus, and the second wife of Zeus. She is the goddess and personification of justice, divine order, fai ...

. Notice elongated formations called yardangs. WikiESP 035295 1885yardangstop.jpg, Yardangs of various sizes, as seen by HiRISE under HiWish program. WikiESP 039563 1730yardangs.jpg, Yardangs formed in light-toned material and surrounded by dark, volcanic basalt sand, as seen by HiRISE under HiWish program. WikiESP 039563 1730yardangsclose.jpg, Close-up image of yardangs, as seen by HiRISE under HiWish program. Arrows point to transverse aeolian ridges, a type of dune.. WikiESP 036429 1925yardangscrater.jpg, Yardangs near a crater, as seen by HiRISE under HiWish program Location is in the Amazonis quadrangle. WikiESP 035558 1830yardang.jpg, Yardangs, as seen by HiRISE under HiWish program Location is near Gordii Dorsum in the Amazonis quadrangle. These yardangs are in the upper member of the Medusae Fossae Formation. 35558 1830yardangs.jpg, Yardangs, as seen by HiRISE under HiWish program Location is near Gordii Dorsum in the Amazonis quadrangle. Note: this is an enlargement of previous image. 35558 1830yardangsclose.jpg, Yardangs, as seen by HiRISE under HiWish program Location is near Gordii Dorsum in the Amazonis quadrangle. Note: this is an enlargement of previous image. Wikiesp036510 1735layersyardang.jpg, Yardangs showing layers, as seen by HiRISE under HiWish program Location is

Aeolis quadrangle The Aeolis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Aeolis quadrangle is also referred to as MC-23 (Mars Chart-23). The Aeolis quadrangle c ...

. ESP 044777 1725yardangs.jpg, Wide view of yardangs, as seen by HiRISE under HiWish program Location is

Memnonia quadrangle The Memnonia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Memnonia quadrangle is also referred to as MC-16 (Mars Chart-16). The quadrangle is ...

. 44777 1725yardangs2.jpg, Close view of yardangs in previous image, as seen by HiRISE under HiWish program Location is

. ESP 047401 1715yardangslayers.jpg, Wide view of yardangs, as seen by HiRISE under HiWish program This image is odd in that the yardangs are lined up in different directions in the top and bottom part of image. The wind direction probably changed to cause this. Location is

References

{{Geography of Mars Geology of Mars Surface features of Mars

See also

References