Dark Sand at the Margin
NASA/JPL/UArizona
Dark Sand at the Margin
ESP_062827_2620  Science Theme: Aeolian Processes
This image covers the boundary between north polar ice and nearby polar sand dunes. The color data clearly distinguishes between the bright ice, dark sand, and reddish dust.

An animation compares an exact same area to how it appeared in March 2009 at the same Martian time of year. The dark sand appears to be on the move, covering much of this area that was formerly bright ice or dust-covered ice. However, this may also show year-on-year variability of seasonal processes. In other words, this area may have looked similar in 2009 a month or so after the HiRISE image was acquired. The seasonal defrosting patterns vary from year to year, perhaps depending on dust storm activity.

Written by: Alfred McEwen (narration: Tre Gibbs)  (17 March 2020)
 
Acquisition date
21 December 2019

Local Mars time
14:06

Latitude (centered)
82.002°

Longitude (East)
225.222°

Spacecraft altitude
318.9 km (198.2 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
0.4°

Phase angle
62.3°

Solar incidence angle
63°, with the Sun about 27° above the horizon

Solar longitude
124.1°, Northern Summer

For non-map projected images
North azimuth:  111°
Sub-solar azimuth:  323.4°
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   (449MB)

IRB color
map-projected   (262MB)

JP2 EXTRAS
Black and white
map-projected  (220MB)
non-map           (170MB)

IRB color
map projected  (64MB)
non-map           (159MB)

Merged IRB
map projected  (111MB)

Merged RGB
map-projected  (103MB)

RGB color
non map           (138MB)
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
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.