Sand Dunes in the Spring
Sand Dunes in the Spring
ESP_025416_2640  Science Theme: Seasonal Processes
In the winter, Martian dunes north of 70 degrees latitude are covered by a seasonal layer of carbon dioxide ice (dry ice). In the spring as the ice sublimates (goes directly from solid to gas) numerous seasonal phenomena are observed.

Mars’ sand dunes are dark, but appear pinkish because they are still covered by ice. Where the ice has cracked, dark sand is visible. On the steep sides of the dunes sand slides down in thin rivulets.

Dark splotches along the crest of the dunes may be sites where gas was released in pops, similar to champagne, carrying sand out in multiple directions.

Written by: Candy Hansen  (29 February 2012)
Acquisition date
28 December 2011

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
317.6 km (197.4 miles)

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

Map projected scale
25 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
65°, with the Sun about 25° above the horizon

Solar longitude
49.6°, Northern Spring

For non-map projected images
North azimuth:  117°
Sub-solar azimuth:  313.1°
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   (592MB)

IRB color
map-projected   (318MB)

Black and white
map-projected  (306MB)
non-map           (252MB)

IRB color
map projected  (114MB)
non-map           (222MB)

Merged IRB
map projected  (143MB)

Merged RGB
map-projected  (141MB)

RGB color
non map           (192MB)
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.