Dunes in Mars’ Polar Erg
Dunes in Mars’ Polar Erg
ESP_018742_2565  Science Theme: Mass Wasting Processes
Near the North Pole of Mars, the landscape is dominated by sand dunes forming a massive erg (sand sea), much like parts of the Sahara Desert on Earth. In parts of the erg, sand is abundant and covers the entire surface. Here near the edge, sand is in shorter supply and the dunes are separated by areas of lighter-toned soil.

Many dunes on Mars are simple crescent-shaped dunes called barchans, which commonly form in sand-starved areas. A very long ridge oriented at a right angle to the wind is called a transverse dune. Here many of the dunes are barchan-like, but they have partially coalesced and deformed into longer, straighter ridges and other, more complex forms. This suggests a more complex interaction between wind and sand.

Written by: Colin Dundas  (1 September 2010)
Acquisition date
26 July 2010

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
318.5 km (198.0 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

Emission angle

Phase angle

Solar incidence angle
59°, with the Sun about 31° above the horizon

Solar longitude
124.0°, Northern Summer

For non-map projected images
North azimuth:  103°
Sub-solar azimuth:  326.4°
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Black & white is 5 km across; enhanced color about 1 km
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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.