Active Sand Abrasion in the Northern Polar Region of Mars
NASA/JPL-Caltech/UArizona
Active Sand Abrasion in the Northern Polar Region of Mars
ESP_026839_2550  Science Theme: Aeolian Processes
The large dune field which surrounds Mars' North Polar cap is actively being modified by the wind, with dunes moving at rates of a meter or more per year (PDF). This new HiRISE image shows that the blowing sand is also abrading the ice-rich ground over which the dunes migrate.

Clearly visible in the black and white and color HiRISE frames is a linear texture on the interdune surface that is oriented north-northeast to south-southwest. This orientation matches that of the horns and slipfaces of the barchan dunes, which together indicate migration from the north-northeast to the south-southwest. Visible here are four zoomed views that provide details of this texture. Zoom A/blue box shows a typical barchan dune. The linear texture is visible, albeit subtly, on the surrounding ground surface.

The texture is more apparent in the next views: A zoom of an interdune surface (Zoom B/red box) shows the wind-etched topography as a series topographic high and lows, with the directional trend indicated by the white arrows. This is also clearly seen next to another dune (Zoom C/yellow box). Further zooming in shows that the topographic highs contain boulders, which may be ice rich (Zoom D/orange box). Most of the sand abrasion probably occurs within the topographic troughs, accentuating topography and abrading away boulders, leaving remnant rocks on the highs. This shows that sand abrasion is actively modifying the surface in Mars’ northern latitudes.

Written by: Nathan Bridges  (6 June 2012)

This is a stereo pair with ESP_027248_2550.
 
Acquisition date
17 April 2012

Local Mars time
14:25

Latitude (centered)
74.884°

Longitude (East)
279.346°

Spacecraft altitude
317.6 km (197.4 miles)

Original image scale range
32.0 cm/pixel (with 1 x 1 binning) so objects ~96 cm across are resolved

Map projected scale
25 cm/pixel

Map projection
Polarstereographic

Emission angle
7.0°

Phase angle
59.4°

Solar incidence angle
53°, with the Sun about 37° above the horizon

Solar longitude
98.3°, Northern Summer

For non-map projected images
North azimuth:  104°
Sub-solar azimuth:  324.3°
JPEG
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

JP2
Black and white
map-projected   (987MB)

IRB color
map-projected   (530MB)

JP2 EXTRAS
Black and white
map-projected  (605MB)
non-map           (448MB)

IRB color
map projected  (277MB)
non-map           (350MB)

Merged IRB
map projected  (259MB)

Merged RGB
map-projected  (245MB)

RGB color
non map           (334MB)
ANAGLYPHS
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

DIGITAL TERRAIN MODEL (DTM)
DTM details page

ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products
HiView

NB
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

USAGE POLICY
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/JPL-Caltech/UArizona

POSTSCRIPT
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.