Dunes on the Rim of the Hellas Impact Basin
NASA/JPL/University of Arizona
Dunes on the Rim of the Hellas Impact Basin
ESP_034101_1385  Science Theme: Aeolian Processes


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Sand dunes like these seen in this image have been observed to creep slowly across the surface of Mars through the action of the wind. These are a particular type of dune called a “barchan”, which forms when the wind blows in one direction (here, east to west) for long periods of time. Barchan dunes are common on Mars and in the desert regions of the Earth.

These barchan dunes are located on the western rim of the Hellas impact basin, in the Southern Hemisphere of Mars. This area is covered by extensive deposits of layered rocks that were initially deposited as loose sediments and over time formed these rock layers. Portions of these layered rocks were subsequently eroded away and the remaining layers now form numerous flat-topped hills called “mesas”. The barchan dunes are forming in the lee (or downwind) of the mesas.

This area was previously image by HiRISE in 2008 and was retargeted here through a public request via HiWish. Careful comparison of repeat images such as these can reveal the speed and manner by which dunes move across the Martian surface. This information can be used to study the current atmosphere of Mars, the age and mobility of sand deposits on the planet’s surface, and the hazards that sand dunes may pose to landed vehicles such as rovers.

Over the course of its mission, the science instruments on board the Mars Reconnaissance Orbiter (MRO) have returned over 200 terabits of data back to Earth. This image was taken on November 4, 2013, the same day that MRO’s 200-terabit mark was surpassed.

Written by: Chris Okubo (audio by Tre Gibbs)  (15 January 2014)
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Acquisition date
04 November 2013

Local Mars time:

Latitude (centered)

Longitude (East)

Range to target site
273.9 km (171.2 miles)

Original image scale range
27.4 cm/pixel (with 1 x 1 binning) so objects ~82 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle:

Phase angle:

Solar incidence angle
74°, with the Sun about 16° above the horizon

Solar longitude
45.0°, Northern Spring

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  51.9°
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Merged IRB
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Black & white is 5 km across; enhanced color about 1 km
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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

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.