- Press Release
- Nov 30, 2022
NASA Mars Odyssey THEMIS Image: Yardangs in Gusev
Context image credit: NASA/Mars Orbiter Laser Altimeter (MOLA) Team
[ Find on map: CGI version ]
Full data on this image has now been released via the THEMIS Data Releases website.
The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.
Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.
Just above the sand dunes in this image are
multiple linear ridges. These ridges are yardangs. On
Earth yardangs are found in desert regions such as the
Gobi Desert of Mongolia. These features are formed by long-term
unidirectional winds in areas of partially or poorly
indurated materials (such as loess, flash flood deposits,
and soils). The wind erosion is cutting the trough between
the ridges – steadily deepening and widening the space.
Erosion rates on Earth have been measured at ~4mm/year of
For more information on terrestrial yardangs see:
“Wind erosion research in China: Past, present and future”,
Shi Peijun, Keynote paper of the 12th International Soil
Conservation Organizaion Conference, 2002, Beijing, China.
[Source: ASU THEMIS Science Team]
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
Image Credit: NASA/JPL/Arizona State University
|[ Show Full-Size Image (GIF) ] [ Show Full-Size Image (JPG) ]|
|[ Show Full-Size Image (PNG) ] [ Show Full-Size Image (TIF) ]|
|[ Printer-friendly version ]|