Dunes on the Move
NASA/JPL/University of Arizona

Dunes on the Move
ESP_027864_2295  Science Theme: Aeolian Processes
French German Spanish Portuguese Italian Dutch Russian Turkish Greek 


HICLIP

720p (MP4)  
Listen to the text  

WALLPAPER

800  1024  
1152  1280  
1440  1600  
1920  2048  
2560  2880 

HIFLYER

PDF, 11 x 17 in  

HISLIDES

PowerPoint  
Keynote  
PDF  
HiRISE has been carrying out a dedicated survey of sand dunes on Mars, determining whether and how fast the dunes move by observing repeatedly at intervals of Martian years. More than 60 sites have been monitored so far, showing that sand dunes from the equator to the poles are advancing at rates of up to 1 meter per Martian year.

These observations are still spotty, however, and tend to be concentrated in the tropics and the North Polar erg (the sand sea that surrounds the North Pole). One latitude band that had not been sampled at all lies between 30 and 65 degrees north. This observation is among a set of images acquired to fill that gap.

This image shows a variety of different dune types in southern Lyot Crater in the Northern lowlands at 48.9 degrees north. Transverse dunes to the west grade into longitudinal dunes downwind to the east and barchans to the south, possibly because of local winds channeled by topography in the impact basin. This image was intended to match the approximate illumination and viewing conditions of an earlier HiRISE observation that was made two Martian years earlier, in August 2008.

Detailed comparison of the two images shows movement on many of the dunes during this interval of nearly four Earth years. The subimage is an animation showing changes on one of the small barchans in the south of the dune field. The area pictured in the subimage is about 100 meters across. Winds from the west (left) have shifted the small ripples up the back of the dune towards the east. Sand has blown over the crest of the dune, cascaded down the steep slip face, and accumulated along the base of the slip face in the lee of the dune. In this way, the small dune advances slowly downwind.

Other images also show dune activity in this latitude band, adding to a growing suspicion that dunes are on the move everywhere on Mars, faster in some places than others.

Written by: Paul Geissler   (1 August 2012)

  Click to share this post on Twitter Click to share this post on Facebook Click to share this post on Google+ Click to share this post on Tumblr


 Image Products: All image links are drag & drop for HiView, or click to download
JPEG
Grayscale: map projected  non-map
IRB color: map projected  non-map
Merged IRB: map projected
Merged RGB: map projected
RGB color: non-map projected

JP2 DOWNLOAD
Grayscale: map-projected (409.7 MB)
IRB color: map-projected (286.0 MB)

JP2 EXTRAS
Grayscale: map-projected  (186.9 MB),
non-map  (126.9 MB)
IRB color: map projected  (81.4 MB)
non-map  (195.6 MB)
Merged IRB: map projected  (114.7 MB)
Merged RGB: map-projected  (109.2 MB)
RGB color: non map-projected  (188.0 MB)

ADDITIONAL IMAGE INFORMATION
Grayscale label   Color label
Merged IRB label   Merged RGB label
EDR products

About color products (PDF)
HiView main page

 Observation Toolbox
Acquisition date:06 July 2012 Local Mars time: 3:11 PM
Latitude (centered):48.905° Longitude (East):29.270°
Range to target site:308.1 km (192.6 miles)Original image scale range:from 30.8 cm/pixel (with 1 x 1 binning) to 61.7 cm/pixel (with 2 x 2 binning)
Map projected scale:25 cm/pixel and North is upMap projection:Equirectangular
Emission angle:5.8° Phase angle:55.4°
Solar incidence angle:50°, with the Sun about 40° above the horizon Solar longitude:135.4°, Northern Summer
For non-map projected products:
North azimuth:98° Sub-solar azimuth:343.6°
For map-projected products
North azimuth:270°Sub solar azimuth:159.3°

Context map

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: Image: NASA/JPL/University of Arizona
Postscript
For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. 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. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.