Aeolian Features, Large and Small
Aeolian Features, Large and Small
PSP_010221_1420  Science Theme: Rocks and Regolith
One of the most important processes on present-day Mars is wind. Aeolian (wind-related) features are found in most regions of the planet. This image shows a diverse array of such features: large dunes, small ripples, and dust-devil tracks (the dark, arcing structures on the dunes).

Dust devils form in many parts of Mars, but they are often particularly distinct on sand dunes. One possibility is that the dust devils dislodge a small amount of fine dust, making the color of dark sand more prominent.

Ripples of wind-blown sand form regular patterns. In the simplest case, wind blowing in a constant direction creates evenly spaced straight ripples at right angles to the wind. More complex wind patterns create more complex ripples, and in this scene variations from linear to polygonal to checkerboard patterns are visible.

This image is particularly interesting because of the occurrence of seasonal frost on the south-facing slopes. (The image is in the Southern Hemisphere, so south faces the pole and gets little winter light). This is particularly apparent in the color swath, as the frost forms pale, purplish patterns. On the dunes, this highlights some of the regular patterns, as the frost forms only on parts of the ripples. The result is an intricately textured pattern of color.

Written by: Colin Dundas  (26 November 2008)
Acquisition date
30 September 2008

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
254.7 km (158.3 miles)

Original image scale range
51.3 cm/pixel (with 2 x 2 binning) so objects ~154 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
76°, with the Sun about 14° above the horizon

Solar longitude
135.0°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  41.6°
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   (349MB)

IRB color
map-projected   (176MB)

Black and white
map-projected  (161MB)
non-map           (213MB)

IRB color
map projected  (70MB)
non-map           (161MB)

Merged IRB
map projected  (315MB)

Merged RGB
map-projected  (298MB)

RGB color
non map           (150MB)
10K (TIFF)
HiClip mini 4K (MP4)

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.