Unusual Gully Channels
Unusual Gully Channels
PSP_002884_1395  Science Theme: Fluvial Processes
This observation shows gullies in a Southern Hemisphere crater, whose floor has large mounds of material that are likely slump blocks that fell off the crater walls during a late stage of formation. There are also a large number of dunes of different sizes and facing different directions on the crater floor.

The gullies visible in this image formed over a period of time. The majority of them have experienced modification since they formed. This can be seen in the form of polygonal fractures on their walls, dunes or ripples on their channel floors, and rocks and material fallen from their walls. Some of the gullies facing east were active more recently. They do not have polygonal fractures or they have fractures that are less well-developed. A narrow, primarily unmodified channel is also visible.

It is unknown over what period of time gullies formed in individual settings and globally. It is possible that gully formation continues today.

Written by: Kelly Kolb  (18 July 2007)

This is a stereo pair with PSP_003517_1395.
Acquisition date
09 March 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
252.2 km (156.7 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

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Emission angle

Phase angle

Solar incidence angle
61°, with the Sun about 29° above the horizon

Solar longitude
197.0°, Northern Autumn

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North azimuth:  97°
Sub-solar azimuth:  22.8°
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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.