Active Dune Gullies in Kaiser Crater
Active Dune Gullies in Kaiser Crater
ESP_025900_1330  Science Theme: Aeolian Processes
Gullies remain an interesting feature to study on Mars, especially because we are still learning about their formation and what processes still act on them.

In this observation, we see large gullies on a huge, barchan dune. We've observed these gullies before, seeing that they appear to be active at different times. When we say "active," we mean that we can see changes in their appearance between different HiRISE images of the same area.

The major objective of this and similar images is to better understand the mechanism for these changes. A specific hypothesis the HiRISE team is investigating is that the changes we see are associated with frost deposits. The frost may be thick and heavy enough to cause parts of the sand dune to collapse, especially if it is "lubricated" by a layer of gas at the base of the frost layer. The gas would form at the bottom of the frost if sunlight passes through the frost and heats the underlying dark sand, working like a greenhouse.

Written by: HiRISE Science Team  (1 April 2012)
Acquisition date
04 February 2012

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
251.7 km (156.4 miles)

Original image scale range
25.4 cm/pixel (with 1 x 1 binning) so objects ~76 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
83°, with the Sun about 7° above the horizon

Solar longitude
66.1°, Northern Spring

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  51.4°
Black and white
map projected  non-map

IRB color
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Merged IRB
map projected

Merged RGB
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RGB color
non-map projected

Black and white
map-projected   (930MB)

IRB color
map-projected   (564MB)

Black and white
map-projected  (422MB)
non-map           (594MB)

IRB color
map projected  (187MB)
non-map           (485MB)

Merged IRB
map projected  (227MB)

Merged RGB
map-projected  (226MB)

RGB color
non map           (467MB)
B&W label
Color label
Merged IRB label
Merged RGB label
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’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.