Widened Gully Alcoves
Widened Gully Alcoves
PSP_005620_1210  Science Theme: Landscape Evolution
This image shows the west wall of a southern hemisphere crater. The scene is covered in dust devil tracks which appear as dark wispy features.

Dust devils are small-scale funnels that move across the surface kicking up dust as they go, thus leaving trails. The crater is covered in small polygons in many locations. These polygons are probably related to periglacial processes; for example, temperature cycling of ice-rich material or sublimation, when gases trapped under the surface escape causing the remaining terrain to collapse to form pits.

Also in this crater are several gullies on the southern wall. These gullies have very wide alcoves/source regions. It is unknown what is responsible for different gully alcove shapes and morphologies.

Written by: Kelly Kolb  (11 June 2008)
Acquisition date
08 October 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
250.4 km (155.6 miles)

Original image scale range
25.0 cm/pixel (with 1 x 1 binning) so objects ~75 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
53°, with the Sun about 37° above the horizon

Solar longitude
327.2°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  48.6°
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Black & white is 5 km across; enhanced color about 1 km
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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.