Opposing Dunes, Opposing Winds
NASA/JPL/University of Arizona
Opposing Dunes, Opposing Winds
ESP_049481_1310  Science Theme: Aeolian Processes


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On the west (left) side of this image, fairly textbook-looking barchan sand dunes sit atop the bedrock. Barchan dunes pointing in the opposite direction are just a few kilometers away to the east.

In between these opposing barchan dunes are star dunes. Barchan dunes form when the sand-moving wind is fairly unidirectional. Star dunes, in contrast, form when the sand-moving wind comes from multiple directions—not all at once, but from varying directions at different times of day or year.

Where is the sand coming from? As with most places on Mars...well, that’s an area of on-going research. But the star dunes are telling us that this area seems to be accumulating sand.

Written by: Kirby Runyon  (4 September 2017)
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Acquisition date
15 February 2017

Local Mars time:
14:15

Latitude (centered)
-48.459°

Longitude (East)
282.463°

Range to target site
248.4 km (155.2 miles)

Original image scale range
49.7 cm/pixel (with 2 x 2 binning) so objects ~149 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle:
2.0°

Phase angle:
41.0°

Solar incidence angle
42°, with the Sun about 48° above the horizon

Solar longitude
317.6°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  44.0°
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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.