A World of Snowy Dunes
NASA/JPL-Caltech/UArizona
A World of Snowy Dunes
ESP_050703_2560  Science Theme: Seasonal Processes
It was spring (2017) in the Northern Hemisphere when we took this image. Over the winter, snow and ice have inexorably covered the dunes. Unlike on Earth, this snow and ice is carbon dioxide, better known to us as dry ice.

When the sun starts shining on it in the spring, the ice on the smooth surface of the dune cracks and escaping gas carries dark sand out from the dune below, often creating beautiful patterns. On the rough surface between the dunes, frost is trapped behind small sheltered ridges.

Written by: Candy Hansen (narration: Tre Gibbs)  (21 August 2017)
 
Acquisition date
21 May 2017

Local Mars time
13:21

Latitude (centered)
75.597°

Longitude (East)
13.493°

Spacecraft altitude
319.4 km (198.5 miles)

Original image scale range
32.4 cm/pixel (with 1 x 1 binning) so objects ~97 cm across are resolved

Map projected scale
25 cm/pixel

Map projection
Polarstereographic

Emission angle
9.7°

Phase angle
79.2°

Solar incidence angle
73°, with the Sun about 17° above the horizon

Solar longitude
7.8°, Northern Spring

For non-map projected images
North azimuth:  105°
Sub-solar azimuth:  305.5°
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   (780MB)

IRB color
map-projected   (448MB)

JP2 EXTRAS
Black and white
map-projected  (463MB)
non-map           (339MB)

IRB color
map projected  (221MB)
non-map           (257MB)

Merged IRB
map projected  (207MB)

Merged RGB
map-projected  (189MB)

RGB color
non map           (228MB)
BONUS
4K (TIFF)
8K (TIFF)

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.