Shapes and Spots on a Polar Sand Dune
NASA/JPL-Caltech/UArizona
Shapes and Spots on a Polar Sand Dune
ESP_034441_2565  Science Theme: Seasonal Processes
This image shows numerous dark shapes and bright spots on a sand dune in the northern polar regions of Mars.

The bright spots are carbon dioxide frost. On Mars, the main atmospheric component is carbon dioxide, which circulates seasonally between the atmosphere and the polar regions. One of the reasons that permit this process is the fact that temperatures on Mars are much colder than on Earth, which allows carbon dioxide frost to condense on the surface in winter.

When spring comes however, the surface heats up and the carbon dioxide frost eventually sublimates (turns directly from the solid to the vapor state), and forms jets of carbon dioxide mixed with dust, leading to the formation of the dark features we see in the image.

Such processes occur seasonally on Mars, and therefore are continuously being monitored by the HiRISE scientists to assess the differences from one year to the next.

Written by: M. Ramy El-Maarry (naration: Tre Gibbs)  (22 January 2014)
 
Acquisition date
01 December 2013

Local Mars time
14:09

Latitude (centered)
76.183°

Longitude (East)
95.411°

Spacecraft altitude
317.8 km (197.5 miles)

Original image scale range
31.9 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
6.0°

Phase angle
62.5°

Solar incidence angle
58°, with the Sun about 32° above the horizon

Solar longitude
56.8°, Northern Spring

For non-map projected images
North azimuth:  105°
Sub-solar azimuth:  319.4°
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non-map           (347MB)

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non-map           (297MB)

Merged IRB
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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.