Indicators of Recent Winds on Mars
Indicators of Recent Winds on Mars
PSP_007153_2505  Science Theme: Glacial/Periglacial Processes
Windblown sand can be used to tell us the wind direction on Mars. Small-scale features, such as ripples and wind tails, indicate the most recent wind directions.

Wind tails may be the remnants of a formerly widespread mantle of sediment that has been removed. Alternatively, they may have formed when aeolian sediment is deposited in the wind-shadow zone behind obstacles such as the 1.5 meter diameter boulders on the crater rim. Their orientation points in the downwind direction. In the figure, two wind tails extend from some boulders indicating winds from at least two directions.

Ripples occur on the surface of all dunes imaged at HiRISE resolution on Mars. The alignment of ripples often results from the influence of more than one wind direction. In this figure, the ripples are superimposed on a low dome dune. On Earth, ripples on the surface of sand dunes may re-orientate in a matter of hours. The time required to re-orientate ripples on Mars is unknown.

Written by: Mary Bourke/Cathy Weitz  (25 June 2008)
Acquisition date
04 February 2008

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
315.2 km (195.9 miles)

Original image scale range
31.6 cm/pixel (with 1 x 1 binning) so objects ~95 cm across are resolved

Map projected scale
25 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
63°, with the Sun about 27° above the horizon

Solar longitude
27.4°, Northern Spring

For non-map projected images
North azimuth:  100°
Sub-solar azimuth:  315.3°
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IRB color
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Black and white
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non-map           (439MB)

IRB color
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non-map           (321MB)

Merged IRB
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Merged RGB
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RGB color
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B&W label
Color label
Merged IRB label
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EDR products

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

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.