Linear Dunes in the North Polar Region
NASA/JPL/University of Arizona
Linear Dunes in the North Polar Region
PSP_009739_2580  Science Theme: Aeolian Processes
Greek  Italian  Spanish 


800  1024  
1152  1280  
1440  1600  
1920  2048  
This observation shows linear dunes in the north polar region of Mars. Linear or longitudinal sand dunes are elongated, sharp crested ridges that are typically separated by a sand-free surrounding surface.

These features form from bi-directional winds and extend parallel to the net wind direction. In this case, the net wind direction appears to be from the west-southwest. Linear sand dunes are found in many different locations on Earth and commonly occur in long parallel chains with regular spacing.

Superimposed on the surface of the linear dunes are smaller secondary dunes or ripples. This is commonly observed on terrestrial dunes of this size as well. Polygons formed by networks of cracks cover the substrate between the linear dunes and may indicate that ice-rich permafrost (permanently frozen ground) is present or has been present geologically recently in this location.

Written by: Maria Banks   (22 October 2008)

Click to share this post on Twitter Click to share this post on Facebook Click to share this post on Google+ Click to share this post on Tumblr

Acquisition date
24 August 2008

Local Mars time:

Latitude (centered)

Longitude (East)

Range to target site
317.9 km (198.7 miles)

Original image scale range
from 31.8 cm/pixel (with 1 x 1 binning) to 63.6 cm/pixel (with 2 x 2 binning)

Map projected scale
25 cm/pixel

Map projection

Emission angle:

Phase angle:

Solar incidence angle
59°, with the Sun about 31° above the horizon

Solar longitude
117.1°, Northern Summer

North azimuth:

Sub-solar azimuth:
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   (1771MB)

IRB color
map-projected   (911MB)

Black and white
map-projected  (919MB)
non-map           (553MB)

IRB color
map projected  (378MB)
non-map           (660MB)

Merged IRB
map projected  (506MB)

Merged RGB
map-projected  (487MB)

RGB color
non map           (658MB)
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/JPL/University of Arizona

For information about NASA and agency programs on the Web, visit: 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. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.