Layers and Slope Streaks within Valleys along the Highland-Lowland Boundary
NASA/JPL/UArizona
Layers and Slope Streaks within Valleys along the Highland-Lowland Boundary
PSP_005574_1720  Science Theme: Mass Wasting Processes
This image shows slope streaks and layering on the walls of a valley along the border between the Martian southern highlands and northern lowlands (see the subimage). At the bottom of the valley and in the lower portion of the valley walls are many large dunes.

The slope streaks generally start at a point source and widen downslope as a single streak or branch into multiple streaks. Some of the slope streaks show evidence that downslope movement is being diverted around obstacles, such as large boulders. In particular, several of the slope streaks in this image appear to be diverting around individual dunes, with downslope movement occurring in the low troughs between the dunes. The darkest slope streaks are youngest and cross cut and lie on top of the older and lighter-toned streaks. The lighter-toned streaks are believed to be dark streaks that are lightening with time as new dust is deposited on their surface.

Slope streak formation is among the few known processes currently active on Mars. Since the slope streaks in this image appear to superpose (lie on top of) the surfaces between individual dunes, the streaks most likely formed more recently and are younger than the dunes.

Many hypotheses have been proposed for the formation of slope streaks including dry avalanching, geochemical weathering, liquid stains or flows, and moisture wickering. Recent observations from HiRISE images have revealed that the dark interior of slope streaks is lower in elevation than the surroundings, suggesting that material must have been removed in the formation of the streak.

Written by: Maria Banks  (12 March 2008)
 
Acquisition date
04 October 2007

Local Mars time
14:14

Latitude (centered)
-7.943°

Longitude (East)
192.173°

Spacecraft altitude
265.2 km (164.8 miles)

Original image scale range
53.1 cm/pixel (with 2 x 2 binning) so objects ~159 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle
0.1°

Phase angle
33.5°

Solar incidence angle
33°, with the Sun about 57° above the horizon

Solar longitude
325.2°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  352.6°
JPEG
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
map projected

RGB color
non-map projected

JP2
Black and white
map-projected   (662MB)

IRB color
map-projected   (242MB)

JP2 EXTRAS
Black and white
map-projected  (369MB)
non-map           (416MB)

IRB color
map projected  (208MB)
non-map           (371MB)

Merged IRB
map projected  (733MB)

Merged RGB
map-projected  (689MB)

RGB color
non map           (354MB)
ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products
HiView

NB
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

USAGE POLICY
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

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.