Yardangs in Arsinoes Chaos
Yardangs in Arsinoes Chaos
ESP_039563_1730  Science Theme: Geologic Contacts/Stratigraphy
Several terrain types converge in this scene from Arsinoes Chaos, in the far eastern portions of Valles Marineris. The jumbled chaos terrain is likely related to the massive water-carved outflow channels that started in this area and flowed north across Mars’ hemispheric dichotomy and onto the northern plains.

The slightly curving, sublinear bright terrain is composed of yardangs. Yardangs are portions of rock that have been sand blasted into long, skinny ridges by saltating (or bouncing) sand particles blowing in the wind.

Zooming in, you can see transverse sand ridges between the yardangs. These sand ridges are termed “transverse aeolian ridges” (TAR) and are currently not moving in Mars’ current climate. TAR are a mystery—they are mid-way in height between dunes (formed from saltating sand) and ripples (formed by “reptated” or “splashed” sand grains).

Written by: Kirby Runyon (narration: Tre Gibbs)  (4 February 2015)
Acquisition date
04 January 2015

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
266.8 km (165.8 miles)

Original image scale range
26.8 cm/pixel (with 1 x 1 binning) so objects ~80 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
47°, with the Sun about 43° above the horizon

Solar longitude
265.6°, Northern Autumn

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  338.0°
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
map projected

RGB color
non-map projected

Black and white
map-projected   (534MB)

IRB color
map-projected   (309MB)

Black and white
map-projected  (229MB)
non-map           (311MB)

IRB color
map projected  (81MB)
non-map           (278MB)

Merged IRB
map projected  (122MB)

Merged RGB
map-projected  (124MB)

RGB color
non map           (262MB)
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

IRB: infrared-red-blue
RGB: red-green-blue
About color products (PDF)

Black & white is 5 km across; enhanced color about 1 km
For scale, use JPEG/JP2 black & white map-projected images

All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible:

NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA’s Science Mission Directorate, Washington. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.