Late Springtime Defrosting of Northern Dunes
NASA/JPL/University of Arizona
Late Springtime Defrosting of Northern Dunes
ESP_026226_2565  Science Theme: Seasonal Processes
Greek  Italian  Spanish 

HICLIP

720p (MP4)  
Listen to the text  

WALLPAPER

800  1024  
1152  1280  
1440  1600  
1920  2048  
2560  

HIFLYER

PDF, 11 x 17 in  

HISLIDES

PowerPoint  
Keynote  
PDF  
This observation shows dunes in the Martian north polar sand sea (commonly referred to as the "north polar erg") in the process of defrosting.

Every winter, dunes and other surfaces at these northern latitudes are coated with several tens of centimeters of carbon dioxide frost and ice, plus a minor amount of water frost. Details of this process are particularly visible this subimage. The white material is fine grained frost.

The dark, splotchy tones on the dunes may be deposits of particulates deposited from carbon dioxide "geysers" or relatively thick deposits of carbon dioxide ice. The more brownish colors represent defrosted areas. Polygonal patterns on the surface of the dunes are probably cracks in overlying carbon dioxide ice.

Landslides on the dunes' lee slopes are apparent,with a morphology consistent with fluidization from carbon dioxide frost. This and other areas of the north polar region are being investigated by HiRISE to compare to changes in past years.

Written by: Nathan Bridges   (18 April 2012)

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
01 March 2012

Local Mars time:
14:21

Latitude (centered)
76.176°

Longitude (East)
95.376°

Range to target site
316.6 km (197.8 miles)

Original image scale range
31.7 cm/pixel (with 1 x 1 binning) so objects ~95 cm across are resolved

Map projected scale
25 cm/pixel

Map projection
Polarstereographic

Emission angle:
1.7°

Phase angle:
56.0°

Solar incidence angle
55°, with the Sun about 35° above the horizon

Solar longitude
77.2°, Northern Spring

North azimuth:
103°

Sub-solar azimuth:
321.9°
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   (1482MB)

IRB color
map-projected   (885MB)

JP2 EXTRAS
Black and white
map-projected  (731MB)
non-map           (565MB)

IRB color
map projected  (257MB)
non-map           (551MB)

Merged IRB
map projected  (424MB)

Merged RGB
map-projected  (389MB)

RGB color
non map           (489MB)
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/University of Arizona



Postscript
For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. 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.