Abrading Dome Dunes in the North Polar Erg
NASA/JPL/UArizona
Abrading Dome Dunes in the North Polar Erg
PSP_009295_2565  Science Theme: Aeolian Processes
This location is where Mars Global Surveyor (a previous Mars orbiter) saw evidence of dunes that either shrank or completely disappeared over a span of a few years. HiRISE provides new details at higher resolution.

As seen here, the dunes show clear evidence of erosion. Based on the shape of the dunes in this picture, the strongest winds have blown from the lower right (southeast) to upper left (northwest). Streamers of dark sand are visible on the white, frost-covered surface downwind of the dunes. This is particularly prominent at the “horns” of the barchan dunes (these are the dunes with the prominent points at their edges).

Scientists believe these dunes are cemented, by ice, such that the wind is progressively eroding them over time. Future observations by HiRISE will determine if the dunes shrink as indicated by MGS, or maybe even migrate, over time.



Written by: Nathan Briges  (1 September 2008)

This is a stereo pair with PSP_009743_2565.
 
Acquisition date
20 July 2008

Local Mars time
14:51

Latitude (centered)
76.178°

Longitude (East)
95.303°

Spacecraft altitude
316.6 km (196.8 miles)

Original image scale range
63.8 cm/pixel (with 2 x 2 binning) so objects ~191 cm across are resolved

Map projected scale
50 cm/pixel

Map projection
Polarstereographic

Emission angle
6.8°

Phase angle
50.1°

Solar incidence angle
56°, with the Sun about 34° above the horizon

Solar longitude
101.4°, Northern Summer

For non-map projected images
North azimuth:  100°
Sub-solar azimuth:  327.6°
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non-map           (107MB)

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RGB color
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ANAGLYPHS
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Full resolution JP2 download
Anaglyph details page

ADDITIONAL INFORMATION
B&W label
Color label
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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/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.