Astronomy:Yardangs on Mars

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

Yardangs are common in some regions on Mars, especially in the Medusae Fossae Formation. This formation is found in the Amazonis quadrangle and near the equator.[1] 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.[2] [3] Because they exhibit very few impact craters they are believed to be relatively young.[4] 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. Yardangs are parts of rock that have been sand blasted into long, skinny ridges by bouncing sand particles blowing in the wind.[5][6] Layers are seen in parts of the formation. A resistant caprock on the top of yardangs has been observed in Viking,[7] Mars Global Surveyor,[8] and HiRISE photos.[9] 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.

See also


  1. SAO/NASA ADS Astronomy Abstract Service: Yardangs on Mars, Journal of Geophysical Research Vol. 84, Issue B14, 30 December 1979.
  2. Yardangs on Mars, ESA Mars Express, 23 Jul 2004
  3. ESA High-resolution image, Yardangs on Mars near Olympus Mons on Mars, image taken by the High Resolution Stereo Camera (HRSC) on board the ESA Mars Express spacecraft.
  4. THEMIS image of Medusae Fossae Formation, ASU, 2002-04-16
  5. 5.0 5.1 Yardangs in Arsinoes Chaos University of Arizona HiRISE Operations, 04 January 2015
  7. Scott, David H.; Tanaka, Kenneth L. (1982). "Ignimbrites of Amazonis Planitia Region of Mars". Journal of Geophysical Research 87: 1179–1190. doi:10.1029/JB087iB02p01179. Bibcode1982JGR....87.1179S. 
  8. Malin, MC; Carr, MH; Danielson, GE; Davies, ME; Hartmann, WK; Ingersoll, AP; James, PB; Masursky, H et al. (March 1998). "Early views of the martian surface from the Mars Orbiter Camera of Mars Global Surveyor". Science 279 (5357): 1681–5. doi:10.1126/science.279.5357.1681. PMID 9497280. Bibcode1998Sci...279.1681M. 
  9. Mandt, Kathleen E.; De Silva, Shanaka L.; Zimbelman, James R.; Crown, David A. (2008). "The origin of the Medusae Fossae Formation, Mars: Insights from a synoptic approach". Journal of Geophysical Research 113: 12011. doi:10.1029/2008JE003076. Bibcode2008JGRE..11312011M.